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2020 Volume 40 Issue 6
2020, 40(6): 1409-1422
doi: 10.6023/cjoc202003015
Abstract:
Development of efficient and practical asymmetric catalytic reactions plays a pivotal role for the concise syntheses of chiral drugs. Chiral ligands and catalysts are crucial for the selectivity and reactivity of the catalytic reactions. In this account, the design and development of a series of P-chiral mono- and bis-phosphorus ligands were summarized based on a benzooxaphosphane backbone and their applications in the synthesis of chiral drugs. Beside their P-chirality, these ligands are structurally rigid, sterically bulky, and electron-rich, providing good physical properties and tunabilities. Facilitated by these chiral ligands, a series of efficient and practical reactions including asymmetric hydrogenation, asymmetric cross-coupling, asymmetric cyclization, and asymmetric nucleophilic additions have been developed. The excellent conversions, yields, regioselectivities, enantioselectivities, and broad substrate scope have enabled concise and efficient syntheses of a series of chiral drugs.
Development of efficient and practical asymmetric catalytic reactions plays a pivotal role for the concise syntheses of chiral drugs. Chiral ligands and catalysts are crucial for the selectivity and reactivity of the catalytic reactions. In this account, the design and development of a series of P-chiral mono- and bis-phosphorus ligands were summarized based on a benzooxaphosphane backbone and their applications in the synthesis of chiral drugs. Beside their P-chirality, these ligands are structurally rigid, sterically bulky, and electron-rich, providing good physical properties and tunabilities. Facilitated by these chiral ligands, a series of efficient and practical reactions including asymmetric hydrogenation, asymmetric cross-coupling, asymmetric cyclization, and asymmetric nucleophilic additions have been developed. The excellent conversions, yields, regioselectivities, enantioselectivities, and broad substrate scope have enabled concise and efficient syntheses of a series of chiral drugs.
2020, 40(6): 1423-1436
doi: 10.6023/cjoc202002035
Abstract:
Transition-metal catalyzed C-C bond cleavage reaction is one of the most challenge topics, and has drawn considerable attention in recent years. This process has not only emerged as a useful strategy for syntheses of complex molecular skeletons, but also satisfied atom economy. Compared to the noble transition metals catalysis such as Rh, Pd and Ir, the nickel catalysis offered a more cost effective option and exhibited unique activity or selectivity. This recent advances on the Ni-catalyzed C-C bond activations are summarized.
Transition-metal catalyzed C-C bond cleavage reaction is one of the most challenge topics, and has drawn considerable attention in recent years. This process has not only emerged as a useful strategy for syntheses of complex molecular skeletons, but also satisfied atom economy. Compared to the noble transition metals catalysis such as Rh, Pd and Ir, the nickel catalysis offered a more cost effective option and exhibited unique activity or selectivity. This recent advances on the Ni-catalyzed C-C bond activations are summarized.
2020, 40(6): 1437-1447
doi: 10.6023/cjoc202003018
Abstract:
Covalent organic frameworks (COFs) are an emerging class of porous crystalline organic materials connected by covalent bonds. Owing to their high crystallinity, low density, large surface area and designable structures, COFs have potential applications in molecular adsorption and separation, catalysis, optoelectronic devices, and energy storage. Recently, due to their inherent characteristics, COFs have attracted a lot of interests in sensing. The research progress of COFs in sensing, including explosive sensing, humidity sensing, metal ions sensing, pH sensing, biosensing and gas sensing is summarized. Finally, a perspective of the application of COFs in sensing is given.
Covalent organic frameworks (COFs) are an emerging class of porous crystalline organic materials connected by covalent bonds. Owing to their high crystallinity, low density, large surface area and designable structures, COFs have potential applications in molecular adsorption and separation, catalysis, optoelectronic devices, and energy storage. Recently, due to their inherent characteristics, COFs have attracted a lot of interests in sensing. The research progress of COFs in sensing, including explosive sensing, humidity sensing, metal ions sensing, pH sensing, biosensing and gas sensing is summarized. Finally, a perspective of the application of COFs in sensing is given.
2020, 40(6): 1448-1460
doi: 10.6023/cjoc202001019
Abstract:
β, γ-Unsaturated α-ketoester is a class of polyfunctional synthon. Due to its 1, 2-dicarbonyl structure and multiple reactive sites, it has been used for the synthesis of various compounds. In the past twenty years, a number of chiral Lewis acid catalysts and organocatalysts have been applied to asymmetric catalytic reactions using β, γ-unsaturated α-ketoesters and various optically active compounds have been synthesized. The current progress of β, γ-unsaturated α-ketoesters in asymmetric catalysis according to the three different reaction sites, unsaturated acyl conjugate system, carbon-carbon double bond and carbonyl group, is summarized. Finally, the limitation of related reactions and the future development trends are also pointed out.
β, γ-Unsaturated α-ketoester is a class of polyfunctional synthon. Due to its 1, 2-dicarbonyl structure and multiple reactive sites, it has been used for the synthesis of various compounds. In the past twenty years, a number of chiral Lewis acid catalysts and organocatalysts have been applied to asymmetric catalytic reactions using β, γ-unsaturated α-ketoesters and various optically active compounds have been synthesized. The current progress of β, γ-unsaturated α-ketoesters in asymmetric catalysis according to the three different reaction sites, unsaturated acyl conjugate system, carbon-carbon double bond and carbonyl group, is summarized. Finally, the limitation of related reactions and the future development trends are also pointed out.
2020, 40(6): 1461-1472
doi: 10.6023/cjoc202001004
Abstract:
Over the past decade, the C(sp2)-H functionalization has emerged as a powerful methodology due to its high efficiency, simplicity, and high atomic economy. Among them, weak coordination between transition metal and oxygen atom has become an important strategy for C(sp2)-H alkenylation of arenes. In this paper, the transition metal-catalyzed C(sp2)-H alkenylation of substrates containing hydroxy, aryl ether, aldehyde, carbonyl, carboxyl, amide, phosphoric acid and sulfonic acid and their derivatives groups is reviewed, and its future development trends are prospected.
Over the past decade, the C(sp2)-H functionalization has emerged as a powerful methodology due to its high efficiency, simplicity, and high atomic economy. Among them, weak coordination between transition metal and oxygen atom has become an important strategy for C(sp2)-H alkenylation of arenes. In this paper, the transition metal-catalyzed C(sp2)-H alkenylation of substrates containing hydroxy, aryl ether, aldehyde, carbonyl, carboxyl, amide, phosphoric acid and sulfonic acid and their derivatives groups is reviewed, and its future development trends are prospected.
2020, 40(6): 1473-1483
doi: 10.6023/cjoc201911030
Abstract:
This paper focuses on cis-/trans-conformational interchanges of amide bonds in cyclic peptides that contain N-unsubstituted amino acids, N-methylated amino acids, and prolines. Conformational preferences of such cyclic peptides and their analogs are discussed. Proline has strong influences on the conformation due to the five-membered cyclic structure. N-Methylation not only increased the steric hindrance, but also led to increased population of cis-conformation of the amide bond.
This paper focuses on cis-/trans-conformational interchanges of amide bonds in cyclic peptides that contain N-unsubstituted amino acids, N-methylated amino acids, and prolines. Conformational preferences of such cyclic peptides and their analogs are discussed. Proline has strong influences on the conformation due to the five-membered cyclic structure. N-Methylation not only increased the steric hindrance, but also led to increased population of cis-conformation of the amide bond.
2020, 40(6): 1484-1501
doi: 10.6023/cjoc202001018
Abstract:
Compared with the traditional N-O bond-based energetic materials, N-F bond-regulated energetic materials have received worldwide research interest due to their special features of high density, high specific impulse, and high heat release upon combustion with metals. The N-F bond-regulated energetic materials are classified as N-F azoles, (difluoroamino)dinitromethyl-substituted derivatives, gem-bis(difluoramino)-substituted derivatives, and difluoroamino polymers according to their structural characteristics. The recent developments of N-F bond and difluoramino (NF2) energetic derivatives are reviewed. The construction methodologies of N-F bond and difluoroamino groups as well as the synthetic routes to their energetic derivatives are emphatically reviewed. Moreover, the physicochemical and energetic properties of some typical compounds are briefly introduced. It will be the inevitable trend to develop effective, safe, and simple N-F bond and difluoraminiation preparation method, and novel high-performing N-F bond-based azoles and cyclic difluoramino-nitramines with moderate sensitivities and stable structures.
Compared with the traditional N-O bond-based energetic materials, N-F bond-regulated energetic materials have received worldwide research interest due to their special features of high density, high specific impulse, and high heat release upon combustion with metals. The N-F bond-regulated energetic materials are classified as N-F azoles, (difluoroamino)dinitromethyl-substituted derivatives, gem-bis(difluoramino)-substituted derivatives, and difluoroamino polymers according to their structural characteristics. The recent developments of N-F bond and difluoramino (NF2) energetic derivatives are reviewed. The construction methodologies of N-F bond and difluoroamino groups as well as the synthetic routes to their energetic derivatives are emphatically reviewed. Moreover, the physicochemical and energetic properties of some typical compounds are briefly introduced. It will be the inevitable trend to develop effective, safe, and simple N-F bond and difluoraminiation preparation method, and novel high-performing N-F bond-based azoles and cyclic difluoramino-nitramines with moderate sensitivities and stable structures.
2020, 40(6): 1502-1513
doi: 10.6023/cjoc202001011
Abstract:
Aromatic compounds possess a particular fragrance and are widely present in natural products and pharmaceuticals. Among them, benzenes are the most abundant substructures of commercially available small-molecule drugs. Therefore, a variety of synthetic methodologies for the construction of aromatic compounds have been pursued vigorously and some significant progresses have been achieved. The dominant methods are transition metal-catalyzed benzannulation of enynes with alkynes to construct the functionalized benzenes. The synthesis of substituted benzene derivatives receives constant attentions since the formation and development of organocatalysis. Compared to metal catalysis, the organocatalytic benzannulation reaction avoids the introduction of a direct group into the pre-existed arene ring and appears to be tolerant of a broad range of substrates. While organocatalysis has emerged as a promising green and effieient synthetic tool and attracted a great deal of attention from synthetic chemists. The development of organocatalyzed aromatization reactions from acyclic starting materials is featured.
Aromatic compounds possess a particular fragrance and are widely present in natural products and pharmaceuticals. Among them, benzenes are the most abundant substructures of commercially available small-molecule drugs. Therefore, a variety of synthetic methodologies for the construction of aromatic compounds have been pursued vigorously and some significant progresses have been achieved. The dominant methods are transition metal-catalyzed benzannulation of enynes with alkynes to construct the functionalized benzenes. The synthesis of substituted benzene derivatives receives constant attentions since the formation and development of organocatalysis. Compared to metal catalysis, the organocatalytic benzannulation reaction avoids the introduction of a direct group into the pre-existed arene ring and appears to be tolerant of a broad range of substrates. While organocatalysis has emerged as a promising green and effieient synthetic tool and attracted a great deal of attention from synthetic chemists. The development of organocatalyzed aromatization reactions from acyclic starting materials is featured.
2020, 40(6): 1514-1528
doi: 10.6023/cjoc201908030
Abstract:
Chiral primary amine is a kind of important small organic molecule catalyst in the field of asymmetric organocatalysis. Like secondary amine catalyst, primary amine can react with carbonyl compounds to form reactive intermediate of enamine or iminium to catalyze various asymmetric reactions, achieving excellent enantioselectivities. The catalytic asymmetric 1, 2-addition to the electrophilic C=N double bond of imines (involving imine intermediates in the reaction process) is the most efficient way to obtain nitrogen-containing compounds bearing α-chiral center. In recent years, the highly enantioselective asymmetric reaction of imines by chiral primary amine catalysts has made some progress, so this topic is summarized and prospected.
Chiral primary amine is a kind of important small organic molecule catalyst in the field of asymmetric organocatalysis. Like secondary amine catalyst, primary amine can react with carbonyl compounds to form reactive intermediate of enamine or iminium to catalyze various asymmetric reactions, achieving excellent enantioselectivities. The catalytic asymmetric 1, 2-addition to the electrophilic C=N double bond of imines (involving imine intermediates in the reaction process) is the most efficient way to obtain nitrogen-containing compounds bearing α-chiral center. In recent years, the highly enantioselective asymmetric reaction of imines by chiral primary amine catalysts has made some progress, so this topic is summarized and prospected.
2020, 40(6): 1529-1539
doi: 10.6023/cjoc201912029
Abstract:
Remarkable achievements have been made in the construction of carbocyclic (heterocyclic) compounds through cyclization reaction of alkynes. It is vitally important to achieve the high selectivity of cyclization reactions, and neighboring group-participated selective cyclization reaction of alkynes is widely considered as an effective strategy. In this review, the recent advances in neighboring group-participated cyclization reaction of alkynes under transition metal-free conditions are summarized.
Remarkable achievements have been made in the construction of carbocyclic (heterocyclic) compounds through cyclization reaction of alkynes. It is vitally important to achieve the high selectivity of cyclization reactions, and neighboring group-participated selective cyclization reaction of alkynes is widely considered as an effective strategy. In this review, the recent advances in neighboring group-participated cyclization reaction of alkynes under transition metal-free conditions are summarized.
2020, 40(6): 1540-1548
doi: 10.6023/cjoc202002029
Abstract:
1, 3, 4-Oxadiazoles, standing for a class of five-membered heterocyclic compounds with multiple heteroatoms, show anti-inflammatory, anti-convulsant, anti-inositol and other biological activities. They also served as important intermediates in organic synthesis. Thus, the development of general and straightforward methods for their synthesis is of great significance. In this paper one-step synthesis of non-symmetric 2, 5-disubstituted 1, 3, 4-oxadiazole derivatives with good yield was completed under electrocatalytic conditions by using cheap and readily available aldehydes and hydrazides as starting materials. Their structures were confirmed by IR, 1H NMR, 13C NMR and HRMS analyses. The reaction features mild conditions, high atom-economy and wide substrate scope, providing a green and sustainable synthetic protocol for constructing 1, 3, 4-oxadiazole skeleton.
1, 3, 4-Oxadiazoles, standing for a class of five-membered heterocyclic compounds with multiple heteroatoms, show anti-inflammatory, anti-convulsant, anti-inositol and other biological activities. They also served as important intermediates in organic synthesis. Thus, the development of general and straightforward methods for their synthesis is of great significance. In this paper one-step synthesis of non-symmetric 2, 5-disubstituted 1, 3, 4-oxadiazole derivatives with good yield was completed under electrocatalytic conditions by using cheap and readily available aldehydes and hydrazides as starting materials. Their structures were confirmed by IR, 1H NMR, 13C NMR and HRMS analyses. The reaction features mild conditions, high atom-economy and wide substrate scope, providing a green and sustainable synthetic protocol for constructing 1, 3, 4-oxadiazole skeleton.
2020, 40(6): 1571-1577
doi: 10.6023/cjoc202001031
Abstract:
This paper has focused on developing a novel methodology for the total synthesis of quadrangularin A (3) and pallidol (4). These two resveratrol dimers have been obtained from the inexpensive materials of 3, 5-dimethoxybenzaldehyde (5) and 3, 5-dimethoxybenzaldehyde (6) within 9 steps and 11 steps with total yields of 2.6% and 1.3%, respectively. The stilbene skeleton constructed by two symmetric or asymmetric aromatic rings (A and B) has been synthesized simply through Knoevenagel reaction under mild conditions with yield of more than 98%, which expanded the diversity of stilbene skeleton (7), and addressed the problems of limited expansion of asymmetric structure, low yield and complex operation. In addition, the key intermediate of 4-enaldehyde skeleton structure (9) could be used to construct aromatic rings of C and D efficiently, which has thrown light on the expansion of resveratrol dimers with aromatic ring A, B, C and D in diversity structure. All the intermediates and natural products have been characterized by 1H NMR, 13C NMR, and HRMS.
This paper has focused on developing a novel methodology for the total synthesis of quadrangularin A (3) and pallidol (4). These two resveratrol dimers have been obtained from the inexpensive materials of 3, 5-dimethoxybenzaldehyde (5) and 3, 5-dimethoxybenzaldehyde (6) within 9 steps and 11 steps with total yields of 2.6% and 1.3%, respectively. The stilbene skeleton constructed by two symmetric or asymmetric aromatic rings (A and B) has been synthesized simply through Knoevenagel reaction under mild conditions with yield of more than 98%, which expanded the diversity of stilbene skeleton (7), and addressed the problems of limited expansion of asymmetric structure, low yield and complex operation. In addition, the key intermediate of 4-enaldehyde skeleton structure (9) could be used to construct aromatic rings of C and D efficiently, which has thrown light on the expansion of resveratrol dimers with aromatic ring A, B, C and D in diversity structure. All the intermediates and natural products have been characterized by 1H NMR, 13C NMR, and HRMS.
2020, 40(6): 1578-1587
doi: 10.6023/cjoc202001016
Abstract:
Garcinol possesses a wide range of biological activities, such as anti-inflammation, anti-tumors, anti-oxidation, induction of apoptosis and so on. In this paper, the modification of the side chains in garcinol was carried out to enhance its anti-tumor activity. Employing acetylacetone as starting material, three new analogs of garcinol were prepared by means of Michael addition, Knoevenagel condensation, and so on. Furthemore, their biological activity was assessed by methyl thiazolyl tetrazolium (MTT) method and the structure-activity relationship was analyzed. The results showed that the inhibitory activities of the three new analogs on oral squamous cell carcinoma were moderately lower than that of garcinol. Hence, the isoprenyl group at the C4 position and the allylic group at the C8 position might play vital roles for the biological activity of garcinol.
Garcinol possesses a wide range of biological activities, such as anti-inflammation, anti-tumors, anti-oxidation, induction of apoptosis and so on. In this paper, the modification of the side chains in garcinol was carried out to enhance its anti-tumor activity. Employing acetylacetone as starting material, three new analogs of garcinol were prepared by means of Michael addition, Knoevenagel condensation, and so on. Furthemore, their biological activity was assessed by methyl thiazolyl tetrazolium (MTT) method and the structure-activity relationship was analyzed. The results showed that the inhibitory activities of the three new analogs on oral squamous cell carcinoma were moderately lower than that of garcinol. Hence, the isoprenyl group at the C4 position and the allylic group at the C8 position might play vital roles for the biological activity of garcinol.
2020, 40(6): 1598-1607
doi: 10.6023/cjoc201911028
Abstract:
Nineteen novel 3, 4, 5-trimethoxyphenyl coumarin derivatives have been synthesized and evaluated for antitumor activity against three human cancer cell lines (EC-109, PC-3 and MGC-803). These chemical structures were well characterized by NMR and HRMS spectroscopic methods. N-Benzyl-2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)-N-(3, 4, 5-trimethoxy-phenyl)acetamide) (4a) and N-((5-chlorobenzo[b]thiophen-3-yl)methyl)-2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)-N-(3, 4, 5-trimethoxyphenyl)acetamide) (4n) had better inhibitory activity against three kinds of tumor cells than 5-fluorouracil. Compound 4n showed the most potent antitumor activity against PC-3 cells with an IC50 value of 4.18 μmol/L.
Nineteen novel 3, 4, 5-trimethoxyphenyl coumarin derivatives have been synthesized and evaluated for antitumor activity against three human cancer cell lines (EC-109, PC-3 and MGC-803). These chemical structures were well characterized by NMR and HRMS spectroscopic methods. N-Benzyl-2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)-N-(3, 4, 5-trimethoxy-phenyl)acetamide) (4a) and N-((5-chlorobenzo[b]thiophen-3-yl)methyl)-2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)-N-(3, 4, 5-trimethoxyphenyl)acetamide) (4n) had better inhibitory activity against three kinds of tumor cells than 5-fluorouracil. Compound 4n showed the most potent antitumor activity against PC-3 cells with an IC50 value of 4.18 μmol/L.
2020, 40(6): 1608-1617
doi: 10.6023/cjoc202002012
Abstract:
The unique Brønsted basic character of N-heterocyclic carbenes (NHCs) has been used to catalyze the double Michael addition between dienones and cyanoacetates. In the presence of 10 mol% NHC, divinyl ketones reacted with cyano acetates to produce multisubstituted cyclohexanones in 60%~89% yields with 5:1~>20:1 dr. Under the same conditions, benzenedi(enones) underwent double Michael addition with cyano acetates or malononitrile to construct multisubstituted indanes in 77%~98% yields and >20:1 dr.
The unique Brønsted basic character of N-heterocyclic carbenes (NHCs) has been used to catalyze the double Michael addition between dienones and cyanoacetates. In the presence of 10 mol% NHC, divinyl ketones reacted with cyano acetates to produce multisubstituted cyclohexanones in 60%~89% yields with 5:1~>20:1 dr. Under the same conditions, benzenedi(enones) underwent double Michael addition with cyano acetates or malononitrile to construct multisubstituted indanes in 77%~98% yields and >20:1 dr.
2020, 40(6): 1618-1624
doi: 10.6023/cjoc202002009
Abstract:
Hydroamination reaction is the addition of a N-H unit across the unsaturated C-C bond, which provides a convenient route for the formation of C-N bond. Considerable effort has been directed toward the development of multiple catalytic protocols for the hydroamination reaction in the past decades. Despite appreciable progress in this field, the development of general and practical strategy for the hydroamination of amides remains challenging, because the strong electron-with-drawing substituents (acyl, sulfonyl, or phosphinyl) strongly declined the nucleophilicity of the nitrogen. In this paper, a mild and efficient palladium-catalyzed 5-exo-trig hydroamidation of β, γ-unsaturated hydrazones for the synthesis of dihydropyrazoles has been developed. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and produces a series of valuable dihydropyrazoles in good to high yields (63%~88%) under mild reaction conditions. Furthermore, a gram-scale hydroamidation of 1a afforded the dihydropyrazole 2a in 85% yield. In addition, the deuterium labeling experiment demonstrated that N-H is the hydrogen source in this hydroamidation process.
Hydroamination reaction is the addition of a N-H unit across the unsaturated C-C bond, which provides a convenient route for the formation of C-N bond. Considerable effort has been directed toward the development of multiple catalytic protocols for the hydroamination reaction in the past decades. Despite appreciable progress in this field, the development of general and practical strategy for the hydroamination of amides remains challenging, because the strong electron-with-drawing substituents (acyl, sulfonyl, or phosphinyl) strongly declined the nucleophilicity of the nitrogen. In this paper, a mild and efficient palladium-catalyzed 5-exo-trig hydroamidation of β, γ-unsaturated hydrazones for the synthesis of dihydropyrazoles has been developed. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and produces a series of valuable dihydropyrazoles in good to high yields (63%~88%) under mild reaction conditions. Furthermore, a gram-scale hydroamidation of 1a afforded the dihydropyrazole 2a in 85% yield. In addition, the deuterium labeling experiment demonstrated that N-H is the hydrogen source in this hydroamidation process.
2020, 40(6): 1625-1629
doi: 10.6023/cjoc201911023
Abstract:
Using di-tert-butyl peroxide (DTBP) as oxidant, chloroform or carbon tetrachloride as trichloromethyl radical source and reaction solvent, enol silyl ethers derived from aryl ketone was transferred to β, β-dichloro-α, β-unsaturated ketone by trichloromethyl radical addition/elimination. The conditions are mild with avoiding the use of metal catalysts, and the enol silyl ethers substrate has good universality.
Using di-tert-butyl peroxide (DTBP) as oxidant, chloroform or carbon tetrachloride as trichloromethyl radical source and reaction solvent, enol silyl ethers derived from aryl ketone was transferred to β, β-dichloro-α, β-unsaturated ketone by trichloromethyl radical addition/elimination. The conditions are mild with avoiding the use of metal catalysts, and the enol silyl ethers substrate has good universality.
2020, 40(6): 1638-1646
doi: 10.6023/cjoc202002024
Abstract:
In search of novel pyrazole oxime compounds with potent bioactivities, twenty pyrazole oxime derivatives were synthesized by introducing N-pyridylpyrazole unit into pyrazole oxime skeleton, based on the lead of fenpyroximate. The title compounds were structurually characterized by 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay showed that all the title compounds had 100% insecticidal activities against Mythimna separata Walker at 500 μg/mL. Five compounds displayed 100% mortality rate towards Mythimna separata Walker at 100 μg/mL. Two compounds both exhibited 40% mortality rate against Mythimna separata Walker at 20 μg/mL. In addition, three compounds had 40~60% insecticidal activities to Aphis medicaginis at 500 μg/mL. It is worthy of noting that 5-(2-bromophenoxy)-1, 3-dimethyl-1H-pyrazole-4-carbaldehyde-O-{1-(3-chloropyridin-2-yl)-3-[(6-chloropyridin-3-yl)methoxy]-1H-pyrazole-5-formyl}oxime (10b) and 5-(4-t-butylphen-oxy)-1, 3-dimethyl-1H-pyrazole-4-carbaldehyde-O-{1-(3-chloropyridin-2-yl)-3-[(6-chloropyridin-3-yl)methoxy]-1H-pyrazole-5-formyl}oxime (10k) which have potent insecticidal activities against Mythimna separata Walker, can be utilized in insecticide research with further optimization.
In search of novel pyrazole oxime compounds with potent bioactivities, twenty pyrazole oxime derivatives were synthesized by introducing N-pyridylpyrazole unit into pyrazole oxime skeleton, based on the lead of fenpyroximate. The title compounds were structurually characterized by 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay showed that all the title compounds had 100% insecticidal activities against Mythimna separata Walker at 500 μg/mL. Five compounds displayed 100% mortality rate towards Mythimna separata Walker at 100 μg/mL. Two compounds both exhibited 40% mortality rate against Mythimna separata Walker at 20 μg/mL. In addition, three compounds had 40~60% insecticidal activities to Aphis medicaginis at 500 μg/mL. It is worthy of noting that 5-(2-bromophenoxy)-1, 3-dimethyl-1H-pyrazole-4-carbaldehyde-O-{1-(3-chloropyridin-2-yl)-3-[(6-chloropyridin-3-yl)methoxy]-1H-pyrazole-5-formyl}oxime (10b) and 5-(4-t-butylphen-oxy)-1, 3-dimethyl-1H-pyrazole-4-carbaldehyde-O-{1-(3-chloropyridin-2-yl)-3-[(6-chloropyridin-3-yl)methoxy]-1H-pyrazole-5-formyl}oxime (10k) which have potent insecticidal activities against Mythimna separata Walker, can be utilized in insecticide research with further optimization.
2020, 40(6): 1658-1664
doi: 10.6023/cjoc201912016
Abstract:
Cyclooctatetrathiophene (COTh) is a saddle-typed molecule with the interesting property of aggregation induced emission (AIE) discovered recently. In this paper, pyrene was introduced to the framework of COTh as a luminescent group. Three pyrene-COTh derivatives, mono-pyrene substituted COTh (Py-COTh), tetra-pyrene substituted COTh (4Py-COTh) and tetra(tri(trimethylsilyl)cyclooctatetrathiophenyl)pyrene (12TMS-4COTh-Py) were designed and synthesized. Their absorption spectra, fluorescene emission behaviors in solution, rigid state (77 K) and the aggregation state were explored. On the one hand, with increasing pyrene group to the framework of COTh, the molecular conjugation of pyrene-COTh derivatives, Py-COTh and 4Py-COTh changed slightly, but their emission intensity increased heavily with large red shift in both dilute solution and aggregation state. On the other hand, with the increase of COTh group to the framework of pyrene, the molecular conjugation of pyrene-COTh derivatives, Py-COTh and 12TMS-4COTh-Py changed significantly, and their emission intensity increased remarkably with large red shift in dilute solution. The relationship between the photophysical property and molecular structure is remarkably exhibited in our case.
Cyclooctatetrathiophene (COTh) is a saddle-typed molecule with the interesting property of aggregation induced emission (AIE) discovered recently. In this paper, pyrene was introduced to the framework of COTh as a luminescent group. Three pyrene-COTh derivatives, mono-pyrene substituted COTh (Py-COTh), tetra-pyrene substituted COTh (4Py-COTh) and tetra(tri(trimethylsilyl)cyclooctatetrathiophenyl)pyrene (12TMS-4COTh-Py) were designed and synthesized. Their absorption spectra, fluorescene emission behaviors in solution, rigid state (77 K) and the aggregation state were explored. On the one hand, with increasing pyrene group to the framework of COTh, the molecular conjugation of pyrene-COTh derivatives, Py-COTh and 4Py-COTh changed slightly, but their emission intensity increased heavily with large red shift in both dilute solution and aggregation state. On the other hand, with the increase of COTh group to the framework of pyrene, the molecular conjugation of pyrene-COTh derivatives, Py-COTh and 12TMS-4COTh-Py changed significantly, and their emission intensity increased remarkably with large red shift in dilute solution. The relationship between the photophysical property and molecular structure is remarkably exhibited in our case.
Synthesis and Insecticidal Activities of Novel Pyrazole Amide Derivatives Containing a Thiazole Unit
2020, 40(6): 1665-1672
doi: 10.6023/cjoc202001029
Abstract:
In search of novel pyrazole amide compounds possessing good biological activities, a series of pyrazole amides were synthesized by introducing thiazole unit into pyrazole ring via amido bond, based on the lead of tebufenpyrad. The title compounds were structurually confirmed by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay displayed that all the title compounds exhibited 100% insecticidal activities against Oriental armyworm at 500 μg/mL. At the concentration of 500 μg/mL, seven compounds showed 70%~100% mortality rate against Aphis medicaginis. In addition, three compounds had 40%~50% insecticidal activity against Tetranychus cinnabarinus at 500 μg/mL.
In search of novel pyrazole amide compounds possessing good biological activities, a series of pyrazole amides were synthesized by introducing thiazole unit into pyrazole ring via amido bond, based on the lead of tebufenpyrad. The title compounds were structurually confirmed by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay displayed that all the title compounds exhibited 100% insecticidal activities against Oriental armyworm at 500 μg/mL. At the concentration of 500 μg/mL, seven compounds showed 70%~100% mortality rate against Aphis medicaginis. In addition, three compounds had 40%~50% insecticidal activity against Tetranychus cinnabarinus at 500 μg/mL.
2020, 40(6): 1673-1679
doi: 10.6023/cjoc201912038
Abstract:
Palladium catalyzed Buchwald-Hartwig reactions between aryl halides and N-nucleophiles, and the copper catalyzed Chan-Evans-Lam reactions between aryl boronic acids and N-nucleophiles are all effective methods for constructing C-N bonds. Herein, under palladium acetate/tert-butanol system or copper acetate/dichloromethane system, benzophenone hydrazone can react with aryl chlorides and aryl boronic acids to afford corresponding aryl hydrazones, respectively. The obtained products are easily hydrolyzed to form aryl hydrazines, thus providing an indirect pathway to access aryl hydrazines from relatively less toxic reagents.
Palladium catalyzed Buchwald-Hartwig reactions between aryl halides and N-nucleophiles, and the copper catalyzed Chan-Evans-Lam reactions between aryl boronic acids and N-nucleophiles are all effective methods for constructing C-N bonds. Herein, under palladium acetate/tert-butanol system or copper acetate/dichloromethane system, benzophenone hydrazone can react with aryl chlorides and aryl boronic acids to afford corresponding aryl hydrazones, respectively. The obtained products are easily hydrolyzed to form aryl hydrazines, thus providing an indirect pathway to access aryl hydrazines from relatively less toxic reagents.
2020, 40(6): 1680-1688
doi: 10.6023/cjoc201911008
Abstract:
Using water-soluble phosphate salt pillar[5]arene (PP5A) as the host and indicate dye methylene blue (MB) as the guest, the MB/PP5A host-guest inclusion complex was constructed. The fluorescence properties, complexation constants, complexation ratios and binding modes of PP5A and MB were studied. The inclusion complex was applied to competitive fluorescent sensing of paraquat (PQ). When MB is complexed with PP5A receptor, its fluorescence is quenched. When PQ is added to the MB/PP5A sensing system, PQ competes into the cavity of PP5A and MB is detached from the cavity of PP5A, which led to fluorescence recovery. This enables competitive fluorescence sensing of PQ. Therefore, the MB/PP5A fluorescence sensing system can detect PQ sensitively with a minimum detection limit of 3.6×10-7mol·L-1. The probe has the advantages of strong selectivity, simple and fast preparation, response in a wide pH range and good anti-interference performance, and can provide the basis for the sensing detection of PQ in organisms and environments.
Using water-soluble phosphate salt pillar[5]arene (PP5A) as the host and indicate dye methylene blue (MB) as the guest, the MB/PP5A host-guest inclusion complex was constructed. The fluorescence properties, complexation constants, complexation ratios and binding modes of PP5A and MB were studied. The inclusion complex was applied to competitive fluorescent sensing of paraquat (PQ). When MB is complexed with PP5A receptor, its fluorescence is quenched. When PQ is added to the MB/PP5A sensing system, PQ competes into the cavity of PP5A and MB is detached from the cavity of PP5A, which led to fluorescence recovery. This enables competitive fluorescence sensing of PQ. Therefore, the MB/PP5A fluorescence sensing system can detect PQ sensitively with a minimum detection limit of 3.6×10-7mol·L-1. The probe has the advantages of strong selectivity, simple and fast preparation, response in a wide pH range and good anti-interference performance, and can provide the basis for the sensing detection of PQ in organisms and environments.
2020, 40(6): 1689-1696
doi: 10.6023/cjoc201912006
Abstract:
Allylation reactions of trifluoromethylated acylhydrazones with allyltrimethylsilane or pinacolyl allylboronate were found to proceed smoothly in the presence of Lewis acid to afford a series of trifluoromethylated homoallylic N-acylhydrazines with high yields. The results showed that the activity of pinacolyl allylboronate was higher than that of allyltrimethylsilane in allylation of trifluoromethylated acylhydrazones.
Allylation reactions of trifluoromethylated acylhydrazones with allyltrimethylsilane or pinacolyl allylboronate were found to proceed smoothly in the presence of Lewis acid to afford a series of trifluoromethylated homoallylic N-acylhydrazines with high yields. The results showed that the activity of pinacolyl allylboronate was higher than that of allyltrimethylsilane in allylation of trifluoromethylated acylhydrazones.
2020, 40(6): 1697-1703
doi: 10.6023/cjoc201912041
Abstract:
A simple, practical and highly efficient synthesis of multi substituted isoxazole derivatives via cheap metal salt FeCl2-catalyzed direct aerobic oxidative has been developed. Nineteen novel multi-substituted 3, 5-diaryl isoxazole derivtaves were synthesized and a single crystal was successfully cultivated. The products were get with about 70%~90% yields under mild conditions. The structures of products were fully characterized by 1H NMR, 13C NMR, elemental analysis and X-ray crystal.
A simple, practical and highly efficient synthesis of multi substituted isoxazole derivatives via cheap metal salt FeCl2-catalyzed direct aerobic oxidative has been developed. Nineteen novel multi-substituted 3, 5-diaryl isoxazole derivtaves were synthesized and a single crystal was successfully cultivated. The products were get with about 70%~90% yields under mild conditions. The structures of products were fully characterized by 1H NMR, 13C NMR, elemental analysis and X-ray crystal.
2020, 40(6): 1704-1715
doi: 10.6023/cjoc201911034
Abstract:
Twenty nine chalcone derivatives were designed, synthesized and characterized by IR, 1H NMR, 13C NMR and HRMS. The antifungal activities of all the synthesized compounds were determined against five plant pathogenic fungi namely Rhizoctonia solani, Fusarum graminearum, Helminthosporium maydis, Sclerotinia sclerotiorum and Botrytis cinerea. Preliminary results indicated that most of them revealed significant antifungal activity. Among them, (E)-N-(4-(3-(5-bromothiophen-2-yl)acryloyl)phenyl)nicotinamide (4m) (EC50 = 0.057 mg/L) and (E)-2-hydroxy-N-(4-(3-(pyridin-3-yl)acryloyl)phenyl)ace-tamide (6i) (EC50 = 0.054 mg/L) showed the strongest activities against S. sclerotiorum and possessed better antifungal activities than the commercial fungicide of fluopyram (EC50 = 0.244 mg/L). Meanwhile, the inhibitory activities of compounds 4m and 6i were tested against succinate dehydrogenase (SDH). The results displayed that they had also better activities than fluopyram. Molecular docking studies demonstrated that compounds 4m and 6i bound well to SDH and their binding energies were -31.0 and -31.4 kJ/mol, respectively. Moreover, compounds 4m and 6i formed hydrogen bonds with residue B/Trp-230 of SDH, respectively.
Twenty nine chalcone derivatives were designed, synthesized and characterized by IR, 1H NMR, 13C NMR and HRMS. The antifungal activities of all the synthesized compounds were determined against five plant pathogenic fungi namely Rhizoctonia solani, Fusarum graminearum, Helminthosporium maydis, Sclerotinia sclerotiorum and Botrytis cinerea. Preliminary results indicated that most of them revealed significant antifungal activity. Among them, (E)-N-(4-(3-(5-bromothiophen-2-yl)acryloyl)phenyl)nicotinamide (4m) (EC50 = 0.057 mg/L) and (E)-2-hydroxy-N-(4-(3-(pyridin-3-yl)acryloyl)phenyl)ace-tamide (6i) (EC50 = 0.054 mg/L) showed the strongest activities against S. sclerotiorum and possessed better antifungal activities than the commercial fungicide of fluopyram (EC50 = 0.244 mg/L). Meanwhile, the inhibitory activities of compounds 4m and 6i were tested against succinate dehydrogenase (SDH). The results displayed that they had also better activities than fluopyram. Molecular docking studies demonstrated that compounds 4m and 6i bound well to SDH and their binding energies were -31.0 and -31.4 kJ/mol, respectively. Moreover, compounds 4m and 6i formed hydrogen bonds with residue B/Trp-230 of SDH, respectively.
2020, 40(6): 1716-1724
doi: 10.6023/cjoc201911025
Abstract:
A natural tetrasaccharide of α-L-Rhap-(1→3)-α-L-Rhap-(1→3)-[β-D-Glup-(1→4)-]α-L-Rhap was synthesized via [2+2] assembly from 2, 3, 4-tri-O-benzoyl-α-L-rhamnopyranosyl trichloroacetimidate, p-methoxyphenyl 2, 4-di-O-benzoyl-α-L-rhamnopyranoside, 2, 3, 4, 6-tetra-O-benzoyl-β-D-glucopyranosyl trichloroacetimidate and p-methoxyphenyl 2, 3-O-isopro-pyl-α-L-rhamnopyranoside. This tetrasaccharide is a repeating unit of the lipopolisaccharides of the nitrogen fixing bacterium Azospirillum brasilense Sp246. In the reaction of the synthesis unit, silica gel loaded perchloric acid (HClO4-SiO2) was used as acid catalyst, and triethylsilyl group was used as selective protective group to construct a fully protected tetrasaccharide. The synthetic route is short, the reagents are few, and the post-processing is simple. The total yield of target tetrasaccharide is 23% based on L-rhamnose. The structures of the tetrasaccharide were confirmed by 1H NMR, 13C NMR, HRMS and IR spectra.
A natural tetrasaccharide of α-L-Rhap-(1→3)-α-L-Rhap-(1→3)-[β-D-Glup-(1→4)-]α-L-Rhap was synthesized via [2+2] assembly from 2, 3, 4-tri-O-benzoyl-α-L-rhamnopyranosyl trichloroacetimidate, p-methoxyphenyl 2, 4-di-O-benzoyl-α-L-rhamnopyranoside, 2, 3, 4, 6-tetra-O-benzoyl-β-D-glucopyranosyl trichloroacetimidate and p-methoxyphenyl 2, 3-O-isopro-pyl-α-L-rhamnopyranoside. This tetrasaccharide is a repeating unit of the lipopolisaccharides of the nitrogen fixing bacterium Azospirillum brasilense Sp246. In the reaction of the synthesis unit, silica gel loaded perchloric acid (HClO4-SiO2) was used as acid catalyst, and triethylsilyl group was used as selective protective group to construct a fully protected tetrasaccharide. The synthetic route is short, the reagents are few, and the post-processing is simple. The total yield of target tetrasaccharide is 23% based on L-rhamnose. The structures of the tetrasaccharide were confirmed by 1H NMR, 13C NMR, HRMS and IR spectra.
2020, 40(6): 1549-1562
doi: 10.6023/cjoc202004039
Abstract:
A mild and facile two-step strategy has been developed for the synthesis of fluorinated 3, 4-dihydropyrimido-[1, 6-a]-indol-1(2H)-ones through Cp*Rh(Ⅲ)-catalyzed C-H 3, 3-difluoroallylation and N-iodosuccinimide (NIS)-mediated cyclization. This strategy featured broad synthetic generality, unique versatility and high efficiency, which provided a potential tool for the construction of fluorine-containing heterocycles for drug discovery.
A mild and facile two-step strategy has been developed for the synthesis of fluorinated 3, 4-dihydropyrimido-[1, 6-a]-indol-1(2H)-ones through Cp*Rh(Ⅲ)-catalyzed C-H 3, 3-difluoroallylation and N-iodosuccinimide (NIS)-mediated cyclization. This strategy featured broad synthetic generality, unique versatility and high efficiency, which provided a potential tool for the construction of fluorine-containing heterocycles for drug discovery.
2020, 40(6): 1563-1570
doi: 10.6023/cjoc202003012
Abstract:
The reaction of 2-phosphaethynolate anion and primary amines for phosphinecarboxamides synthesis using mechanochemistry has been studied using IR, 13C NMR and 31P NMR spectra, and the reaction occurred under grinding, mild and acid-free conditions at room temperature. In this paper, a comprehensive mechanistic density functional theory (DFT) of B3LYP/6-31G(d, p) study reveals that H shift can be aided/catalyzed with solvents and further the activation free energies barrier can be dramatically decreased, which is responsible for the higher yield of the product in the experiment.
The reaction of 2-phosphaethynolate anion and primary amines for phosphinecarboxamides synthesis using mechanochemistry has been studied using IR, 13C NMR and 31P NMR spectra, and the reaction occurred under grinding, mild and acid-free conditions at room temperature. In this paper, a comprehensive mechanistic density functional theory (DFT) of B3LYP/6-31G(d, p) study reveals that H shift can be aided/catalyzed with solvents and further the activation free energies barrier can be dramatically decreased, which is responsible for the higher yield of the product in the experiment.
2020, 40(6): 1588-1597
doi: 10.6023/cjoc201911002
Abstract:
In this work, the novel fluorescent probes for detecting Fe3+ ions based on nanoparticles (TA-DF-BDM/PSMA NPs) of fluorescence material with twisting D-π-A configuration was designed and prepared, in which triphenylamine (TA), 9, 9-dioctylfluorene (DF) and benzylidenemalononitrile (BDM) serve as electron donor (D) unit, π conjugated unit, and electron acceptor (A) unit, respectively. TA-DF-BDM/PSMA NPs exhibit red-emission peak located at 610 nm in photoluminescence spectrum and larger stokes shifts (ca. 203 nm). And, TA-DF-BDM/PSMA NPs exhibit high selectivity for detecting Fe3+ ions in pure water with high sensitivity and low detection limit of 0.9833 μmol/L. More importantly, TA-DF-BDM/PSMA NPs show such properties as good photophysical stability, reversibility, excellent biocompatibility and low cytotoxicity, which can be utilized in bioimaging investigations.
In this work, the novel fluorescent probes for detecting Fe3+ ions based on nanoparticles (TA-DF-BDM/PSMA NPs) of fluorescence material with twisting D-π-A configuration was designed and prepared, in which triphenylamine (TA), 9, 9-dioctylfluorene (DF) and benzylidenemalononitrile (BDM) serve as electron donor (D) unit, π conjugated unit, and electron acceptor (A) unit, respectively. TA-DF-BDM/PSMA NPs exhibit red-emission peak located at 610 nm in photoluminescence spectrum and larger stokes shifts (ca. 203 nm). And, TA-DF-BDM/PSMA NPs exhibit high selectivity for detecting Fe3+ ions in pure water with high sensitivity and low detection limit of 0.9833 μmol/L. More importantly, TA-DF-BDM/PSMA NPs show such properties as good photophysical stability, reversibility, excellent biocompatibility and low cytotoxicity, which can be utilized in bioimaging investigations.
2020, 40(6): 1630-1637
doi: 10.6023/cjoc201912030
Abstract:
A new, versatile and highly efficient palladium-catalyzed asymmetric ring-opening reaction of oxabenzonor-bornadienes with a wide range of potassium trifluoroborate salts was developed. The corresponding cis-2-aryl-1, 2-dihydronaphthalen-1-ol products were obtained in good yields with moderate to good enantioselectivities under mild conditions.
A new, versatile and highly efficient palladium-catalyzed asymmetric ring-opening reaction of oxabenzonor-bornadienes with a wide range of potassium trifluoroborate salts was developed. The corresponding cis-2-aryl-1, 2-dihydronaphthalen-1-ol products were obtained in good yields with moderate to good enantioselectivities under mild conditions.
2020, 40(6): 1647-1657
doi: 10.6023/cjoc201912042
Abstract:
A series of novel 4-methyl-1, 2, 4-triazole-thioethers containing gem-dimethylcyclopropane ring were designed and synthesized by multi-step reactions in search of potent novel bioactive molecules. Structures of all the target compounds were characterized by means of UV-Vis, FTIR, NMR, ESI-MS, and elemental analysis. The antifungal and herbicidal activities of the target compounds were preliminarily evaluated. As indicated in bioassay results, 2 compounds exhibited excellent antifungal activity against Physalospora piricola, which are much better than that of the commercial fungicide of chlorothalonil used as positive control. Also, at 100 μg/mL, 4 compounds displayed prominent herbicidal activity against the root-growth of rape (Brassica campestris), which are much better than that of the commercial herbicide of flumioxazin used as positive control. In the interest of developing more effective antifungal compounds against P. piricola, the preliminary analysis of three-dimen-sional quantitative structure-activity relationship (3D-QSAR) was carried out using the molecular field analysis (CoMFA) method, and a reasonable and effective 3D-QSAR model (r2=0.985, q2=0.509) has been established.
A series of novel 4-methyl-1, 2, 4-triazole-thioethers containing gem-dimethylcyclopropane ring were designed and synthesized by multi-step reactions in search of potent novel bioactive molecules. Structures of all the target compounds were characterized by means of UV-Vis, FTIR, NMR, ESI-MS, and elemental analysis. The antifungal and herbicidal activities of the target compounds were preliminarily evaluated. As indicated in bioassay results, 2 compounds exhibited excellent antifungal activity against Physalospora piricola, which are much better than that of the commercial fungicide of chlorothalonil used as positive control. Also, at 100 μg/mL, 4 compounds displayed prominent herbicidal activity against the root-growth of rape (Brassica campestris), which are much better than that of the commercial herbicide of flumioxazin used as positive control. In the interest of developing more effective antifungal compounds against P. piricola, the preliminary analysis of three-dimen-sional quantitative structure-activity relationship (3D-QSAR) was carried out using the molecular field analysis (CoMFA) method, and a reasonable and effective 3D-QSAR model (r2=0.985, q2=0.509) has been established.
2020, 40(6): 1725-1730
doi: 10.6023/cjoc202001033
Abstract:
Wogonin is an important flavonoid with a wide range of pharmacological activities, and its research has received increasing attention. The large amount of wogonin is the basis of in-depth research on it, but currently there are problems, such as difficulty in extracting from natural products, difficult to obtain fully synthetic raw materials, harsh reaction conditions, use of valuable and toxic reagents, difficulty in isolation and purification, or low yields. Herein, an efficient synthesis of wogonin from benzene-1, 3, 5-triol as starting material via seven steps with total yield of 58% was reported. This method possesses advantages including available starting materials, mild reaction conditions, simple operation and no column chromatography purification, which will provide a foundation for the large-scale preparation and in-depth study of wogonin.
Wogonin is an important flavonoid with a wide range of pharmacological activities, and its research has received increasing attention. The large amount of wogonin is the basis of in-depth research on it, but currently there are problems, such as difficulty in extracting from natural products, difficult to obtain fully synthetic raw materials, harsh reaction conditions, use of valuable and toxic reagents, difficulty in isolation and purification, or low yields. Herein, an efficient synthesis of wogonin from benzene-1, 3, 5-triol as starting material via seven steps with total yield of 58% was reported. This method possesses advantages including available starting materials, mild reaction conditions, simple operation and no column chromatography purification, which will provide a foundation for the large-scale preparation and in-depth study of wogonin.
2020, 40(6): 1737-1744
doi: 10.6023/cjoc202001020
Abstract:
The selective aminocarbonylation of vicinal diketones using carbamoylsilane as an amide source affords β-keto-α-siloxyamide derivatives in 62%~90% yields under mild conditions without using any oxidants and catalysts. The steric hindrance, which is both from the groups of vicinal diketones and the carbamoylsilanes, affects reaction selectivity on two carbonyl groups. The methoxymethyl or benzyl used as an amino protecting group, can be easily converted into hydrogen atom leading to β-keto-α-hydroxy secondary or primary amides. The simple procedure allows the preparation of various β-keto-α-hydroxy amide derivatives including primary, secondary and tertiary β-keto-α-hydroxy amide derivatives. The reaction has the advantages of mild conditions, less by-products, high selectivity, good yield and simple post-treatment, and it is a new method for the efficient preparation of β-keto-α-hydroxyamides.
The selective aminocarbonylation of vicinal diketones using carbamoylsilane as an amide source affords β-keto-α-siloxyamide derivatives in 62%~90% yields under mild conditions without using any oxidants and catalysts. The steric hindrance, which is both from the groups of vicinal diketones and the carbamoylsilanes, affects reaction selectivity on two carbonyl groups. The methoxymethyl or benzyl used as an amino protecting group, can be easily converted into hydrogen atom leading to β-keto-α-hydroxy secondary or primary amides. The simple procedure allows the preparation of various β-keto-α-hydroxy amide derivatives including primary, secondary and tertiary β-keto-α-hydroxy amide derivatives. The reaction has the advantages of mild conditions, less by-products, high selectivity, good yield and simple post-treatment, and it is a new method for the efficient preparation of β-keto-α-hydroxyamides.
2020, 40(6): 1772-1778
doi: 10.6023/cjoc202001028
Abstract:
In order to find new pyrazole amides with wonderful bioactivities, a series of novel pyrazole amide derivatives were synthesized by introducing substituted oxazole ring into the C-5 position of pyrazole skeleton based on the lead chlorantraniliprole. The aimed compounds were structurally characterized through 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay results exhibited that all the title compounds displayed more than 90% insecticidal activities against Mythimna separata (Walker) at 500 μg/mL. At the dosage of 100 μg/mL, five compounds possessed 90%~100% insecticidal activities against Mythimna separata (Walker), and three compounds exhibited insecticidal property against Aphis craccivora with 90%~100%. Additionally, at the dosage of 500 μg/mL, two compounds possessed insecticidal activity against Tetranychus cinnabarinus with 80%~100%.
In order to find new pyrazole amides with wonderful bioactivities, a series of novel pyrazole amide derivatives were synthesized by introducing substituted oxazole ring into the C-5 position of pyrazole skeleton based on the lead chlorantraniliprole. The aimed compounds were structurally characterized through 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay results exhibited that all the title compounds displayed more than 90% insecticidal activities against Mythimna separata (Walker) at 500 μg/mL. At the dosage of 100 μg/mL, five compounds possessed 90%~100% insecticidal activities against Mythimna separata (Walker), and three compounds exhibited insecticidal property against Aphis craccivora with 90%~100%. Additionally, at the dosage of 500 μg/mL, two compounds possessed insecticidal activity against Tetranychus cinnabarinus with 80%~100%.
2020, 40(6): 1779-1784
doi: 10.6023/cjoc201912017
Abstract:
Montamide A (1), a new polycyclic tetramate macrolactam (PoTeM) with a 5/5/6 tricyclic system was isolated from recombinant strain S001-PoTeMS023, which is derived from Streptomyces sp. S001 by introducing a new PoTeM biosynthetic gene cluster cftS023. The chemical structure of 1 was elucidated by different spectroscopic techniques including HRMS, 1D and 2D-NMR and ECD spectroscopies. The antibacterial and antifungal activities of compound 1 were carried out by filter paper disc diffusion assay. The results showed that compound 1 has no effect on tested strains at 40 μg/disc. The cytotoxicity of compound 1 was evaluated by methyl thiazolyl tetrazolium (MTT) assay using doxorubicin as a positive control. Compound 1 showed weak antiproliferative activity against human lung carcinoma cell line A549 (IC50~22.6 μmol/L), and the substitution at C16 was critical for the cytotoxicity of compound 1. In addition, the biosynthetic gene cluster of compound 1 was identified and the biosynthetic pathway of compound 1 was proposed.
Montamide A (1), a new polycyclic tetramate macrolactam (PoTeM) with a 5/5/6 tricyclic system was isolated from recombinant strain S001-PoTeMS023, which is derived from Streptomyces sp. S001 by introducing a new PoTeM biosynthetic gene cluster cftS023. The chemical structure of 1 was elucidated by different spectroscopic techniques including HRMS, 1D and 2D-NMR and ECD spectroscopies. The antibacterial and antifungal activities of compound 1 were carried out by filter paper disc diffusion assay. The results showed that compound 1 has no effect on tested strains at 40 μg/disc. The cytotoxicity of compound 1 was evaluated by methyl thiazolyl tetrazolium (MTT) assay using doxorubicin as a positive control. Compound 1 showed weak antiproliferative activity against human lung carcinoma cell line A549 (IC50~22.6 μmol/L), and the substitution at C16 was critical for the cytotoxicity of compound 1. In addition, the biosynthetic gene cluster of compound 1 was identified and the biosynthetic pathway of compound 1 was proposed.
2020, 40(6): 1731-1736
doi: 10.6023/cjoc202001034
Abstract:
In order to find more effective antitumor drugs, a series of novel hydrazone-substituted pyrimidine derivatives were designed, synthesized and evaluated for their antitumor activity against five different human cancer cell lines including MCF-7 (human breast cancer cell), MGC-803 (human gastric cancer cell), PC-3 (human prostate cancer cell), Hela (human cervical cancer cell) and A549 (human lung cancer cell) using methyl thiazolyl tetrazolium (MTT) assay. Most of the target compounds showed moderate to potent antitumor activity against five selected cancer cell lines. Among them, 2-(prop-2-yn-1-ylthio)-4-(2-(pyridin-2-ylmethylene)-hydrazinyl)-6-(trifluoromethyl)pyrimidine (12l) displayed the most potent anti-proliferative activity against PC-3 cell line (IC50 = 1.37 μmol·L-1), which was significantly better than the positive control drug 5-fluorouracil. This work provided clues to discover new antitumor agents.
In order to find more effective antitumor drugs, a series of novel hydrazone-substituted pyrimidine derivatives were designed, synthesized and evaluated for their antitumor activity against five different human cancer cell lines including MCF-7 (human breast cancer cell), MGC-803 (human gastric cancer cell), PC-3 (human prostate cancer cell), Hela (human cervical cancer cell) and A549 (human lung cancer cell) using methyl thiazolyl tetrazolium (MTT) assay. Most of the target compounds showed moderate to potent antitumor activity against five selected cancer cell lines. Among them, 2-(prop-2-yn-1-ylthio)-4-(2-(pyridin-2-ylmethylene)-hydrazinyl)-6-(trifluoromethyl)pyrimidine (12l) displayed the most potent anti-proliferative activity against PC-3 cell line (IC50 = 1.37 μmol·L-1), which was significantly better than the positive control drug 5-fluorouracil. This work provided clues to discover new antitumor agents.
2020, 40(6): 1745-1751
doi: 10.6023/cjoc201912007
Abstract:
2, 2', 2''-(1, 3, 5-Triazine-2, 4, 6-triimino)tribenzoic acid (L, H3TATIB) fluorescence response chemosensor has been synthesized by one pot reaction and its fluorescent behaviors to transition metal ions were systematically investigated. The experimental results show that the recognition of Zr4+ and Fe3+ is realized in N, N-dimethylformamide (DMF) aqueous solution; The compound L can effectively detect acetone in organic solvent. The detection limits of Zr4+ and Fe3+ are 3.60×10-6 and 1.33×10-6 mol/L, respectively. It was preliminarily explored that compound L was used as a fluorescent probe to identify Fe3+ ion in human urine and water samples.
2, 2', 2''-(1, 3, 5-Triazine-2, 4, 6-triimino)tribenzoic acid (L, H3TATIB) fluorescence response chemosensor has been synthesized by one pot reaction and its fluorescent behaviors to transition metal ions were systematically investigated. The experimental results show that the recognition of Zr4+ and Fe3+ is realized in N, N-dimethylformamide (DMF) aqueous solution; The compound L can effectively detect acetone in organic solvent. The detection limits of Zr4+ and Fe3+ are 3.60×10-6 and 1.33×10-6 mol/L, respectively. It was preliminarily explored that compound L was used as a fluorescent probe to identify Fe3+ ion in human urine and water samples.
2020, 40(6): 1752-1759
doi: 10.6023/cjoc201912039
Abstract:
A novel and simple method for the selectively oxidation of sulfides to sulfoxides and oxidation of disulfides to thiosulfonates in the presence of t-butyl hydroperoxide (TBHP) has been established. The oxidation system has the advantages of avoiding the use of any catalyst and additive, possessing a broad substrate scope and high efficiency. Desired sulfoxides and thiosulfonates products were obtained in moderate to good yields. Furthermore, a plausible mechanism of the reaction is proposed. The results of control experiments revealed that a radical pathway was involved in this oxidation.
A novel and simple method for the selectively oxidation of sulfides to sulfoxides and oxidation of disulfides to thiosulfonates in the presence of t-butyl hydroperoxide (TBHP) has been established. The oxidation system has the advantages of avoiding the use of any catalyst and additive, possessing a broad substrate scope and high efficiency. Desired sulfoxides and thiosulfonates products were obtained in moderate to good yields. Furthermore, a plausible mechanism of the reaction is proposed. The results of control experiments revealed that a radical pathway was involved in this oxidation.
2020, 40(6): 1760-1765
doi: 10.6023/cjoc201912022
Abstract:
By introducing benzyloxy into the molecule, the as-prepared 1, 2-bis(4-(benzyloxy)phenyl)diselane showed superior activity in copper pollutant elimination over simple diselenides in regardless of their electron-donating or electron-with-drawing substituents. The copper-adsorption process occurred smoothly at room temperature and could completely remove the Cu2+ ions within 4 h. The compound has been successfully employed in our Imatinib base synthetic project to reduce the catalytic Cu residue in product. By using only 1 mol% 1, 2-bis(4-(benzyloxy)phenyl)diselane, the Cu residue in the produced Imatinib base could be depressed to be less than 10-7, showing good application potential of torganoselenium compound in pharmaceutical industry. A novel method for removing copper residue is reported and it may be applied in pharmaceutical industry owing to the safe and metabolizable features of selenium.
By introducing benzyloxy into the molecule, the as-prepared 1, 2-bis(4-(benzyloxy)phenyl)diselane showed superior activity in copper pollutant elimination over simple diselenides in regardless of their electron-donating or electron-with-drawing substituents. The copper-adsorption process occurred smoothly at room temperature and could completely remove the Cu2+ ions within 4 h. The compound has been successfully employed in our Imatinib base synthetic project to reduce the catalytic Cu residue in product. By using only 1 mol% 1, 2-bis(4-(benzyloxy)phenyl)diselane, the Cu residue in the produced Imatinib base could be depressed to be less than 10-7, showing good application potential of torganoselenium compound in pharmaceutical industry. A novel method for removing copper residue is reported and it may be applied in pharmaceutical industry owing to the safe and metabolizable features of selenium.
2020, 40(6): 1766-1771
doi: 10.6023/cjoc202002002
Abstract:
The C-2 alkylation of ethers and N-oxides was achieved via free radical coupling reaction under metal-free conditions. The reaction conditions are mild, and the desired products can be obtained in medium to high yields with the addition of the oxidant di-tert-butyl peroxide (DTBP).
The C-2 alkylation of ethers and N-oxides was achieved via free radical coupling reaction under metal-free conditions. The reaction conditions are mild, and the desired products can be obtained in medium to high yields with the addition of the oxidant di-tert-butyl peroxide (DTBP).
2020, 40(6): 1785-1786
doi: 10.6023/cjoc202000029
Abstract:
2020, 40(6): 1787-1789
doi: 10.6023/cjoc202000030
Abstract:
2020, 40(6): 1790-1791
doi: 10.6023/cjoc202000031
Abstract:
2020, 40(6): 1792-1793
doi: 10.6023/cjoc202000032
Abstract:
2020, 40(6): 1794-1796
doi: 10.6023/cjoc202000033
Abstract:
2020, 40(6): 1797-1799
doi: 10.6023/cjoc202000034
Abstract:
2020, 40(6): 1800-1801
doi: 10.6023/cjoc202000035
Abstract:
2020, 40(6): 1802-1803
doi: 10.6023/cjoc202000036
Abstract:
