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2020 Volume 40 Issue 5
2020, 40(5): 1087-1095
doi: 10.6023/cjoc202002017
Abstract:
Catalytic asymmetric hydrofunctionalization of alkene is an important research field, which enables efficient construction of chiral molecules from readily available starting materials. Asymmetric hydrofunctionalization of multiple substituted alkenes represents a significant challenge to organic chemists because this process involves the simutaneous control of regio-, diastereo-, and enantio-selectivities. The key to solve this challenge is to identify novel catalyst systems to exert powerful regio- and stereo-control. Recently, by taking advantage of substrate-directed strategy, we have developed a number of alkene functionalization methods with excellent regio-, diastereo-, and enantio-selectivities. In particular, we focus on catalytic asymmetric hydroalkynylation of alkenes as a model transformation to analyze the factors that control the selectivity.
Catalytic asymmetric hydrofunctionalization of alkene is an important research field, which enables efficient construction of chiral molecules from readily available starting materials. Asymmetric hydrofunctionalization of multiple substituted alkenes represents a significant challenge to organic chemists because this process involves the simutaneous control of regio-, diastereo-, and enantio-selectivities. The key to solve this challenge is to identify novel catalyst systems to exert powerful regio- and stereo-control. Recently, by taking advantage of substrate-directed strategy, we have developed a number of alkene functionalization methods with excellent regio-, diastereo-, and enantio-selectivities. In particular, we focus on catalytic asymmetric hydroalkynylation of alkenes as a model transformation to analyze the factors that control the selectivity.
2020, 40(5): 1096-1104
doi: 10.6023/cjoc201912025
Abstract:
Transition metal complexes-catalyzed homogeneous asymmetric hydrogenation is an important method for the synthesis of chiral compounds. At present, it is mainly focused on precious transition metal catalytic systems, such as ruthenium, rhodium, iridium and palladium. However, they are suffered from the difficulties of limited resource, high cost and environmental contamination. Therefore, it is important and necessary to develop catalytic systems based on cheap, non-toxic or low toxic, environmentally friendly and earth-abundant iron, cobalt, nickel, copper transition metal, which are in accordance with the requirements and research trend of the sustainable development of modern chemistry. The recent progress of nickel-catalyzed homogeneous asymmetric hydrogenation of prochiral unsaturated compounds containing carbon oxygen double bond (C=O), carbon carbon double bond (C=C) and carbon nitrogen double bond (C=N) is reviewed, and some breakthroughs and considerable research results achieved are introduced. In addition, the advantages and disadvantages of different types of substrates in nickel catalyst system are analyzed, and the future research direction is prospected.
Transition metal complexes-catalyzed homogeneous asymmetric hydrogenation is an important method for the synthesis of chiral compounds. At present, it is mainly focused on precious transition metal catalytic systems, such as ruthenium, rhodium, iridium and palladium. However, they are suffered from the difficulties of limited resource, high cost and environmental contamination. Therefore, it is important and necessary to develop catalytic systems based on cheap, non-toxic or low toxic, environmentally friendly and earth-abundant iron, cobalt, nickel, copper transition metal, which are in accordance with the requirements and research trend of the sustainable development of modern chemistry. The recent progress of nickel-catalyzed homogeneous asymmetric hydrogenation of prochiral unsaturated compounds containing carbon oxygen double bond (C=O), carbon carbon double bond (C=C) and carbon nitrogen double bond (C=N) is reviewed, and some breakthroughs and considerable research results achieved are introduced. In addition, the advantages and disadvantages of different types of substrates in nickel catalyst system are analyzed, and the future research direction is prospected.
2020, 40(5): 1105-1116
doi: 10.6023/cjoc201912024
Abstract:
The CHF2 moiety has been widely utilized in the design of pharmaceuticals and agrochemicals, because this group can act as hydrogen-bonding donor to improve the binding selectivity of biologically active compounds, as a bioisostere to substitute for methyl, methoxy, hydroxy, amino and thiol groups, and as a lipophilic regulator to improve the liposolubility of the active compounds. For example, 3-difluoromethylpyrazole scaffolds are present in many organic compounds that exhibit important biological activities. In this content, there are nearly ten kinds of pesticide molecules on the market that contain 3, 4-disubstituted-3-(difluoromethyl)pyrazole units, with annual sales of up to one billion dollars. In this review, the methods of construction of 3, 4-disubstituted 3-difluoromethylpyrazoles will been briefly summarized that have been reported so far. Four different strategies including using fluorinated reagents as substrates, difluoroacetic acid and its derivatives as fluorine building blocks, difluorodiazonium and others as fluorine building blocks will be introduced.
The CHF2 moiety has been widely utilized in the design of pharmaceuticals and agrochemicals, because this group can act as hydrogen-bonding donor to improve the binding selectivity of biologically active compounds, as a bioisostere to substitute for methyl, methoxy, hydroxy, amino and thiol groups, and as a lipophilic regulator to improve the liposolubility of the active compounds. For example, 3-difluoromethylpyrazole scaffolds are present in many organic compounds that exhibit important biological activities. In this content, there are nearly ten kinds of pesticide molecules on the market that contain 3, 4-disubstituted-3-(difluoromethyl)pyrazole units, with annual sales of up to one billion dollars. In this review, the methods of construction of 3, 4-disubstituted 3-difluoromethylpyrazoles will been briefly summarized that have been reported so far. Four different strategies including using fluorinated reagents as substrates, difluoroacetic acid and its derivatives as fluorine building blocks, difluorodiazonium and others as fluorine building blocks will be introduced.
2020, 40(5): 1117-1128
doi: 10.6023/cjoc201912011
Abstract:
Thiocyanate, as a versatile synthon, which has important application value in many fields such as pharmaceutical, pesticide and materials. The photocatalytic and electrocatalytic thiocyanation reactions have been widely concerned in organic chemistry due to the advantages of green, efficiency and safety. In this review, the cross-coupling/thiocyanation reactions based on the photocatalytic and electrocatalytic are described, which is expected to be helpful in exploring the green synthesis of thiocyanates compounds.
Thiocyanate, as a versatile synthon, which has important application value in many fields such as pharmaceutical, pesticide and materials. The photocatalytic and electrocatalytic thiocyanation reactions have been widely concerned in organic chemistry due to the advantages of green, efficiency and safety. In this review, the cross-coupling/thiocyanation reactions based on the photocatalytic and electrocatalytic are described, which is expected to be helpful in exploring the green synthesis of thiocyanates compounds.
2020, 40(5): 1129-1149
doi: 10.6023/cjoc201911011
Abstract:
Optically pure 1, 3-amino alcohol is not only the important synthon in organic synthesis, but also the core structure of numerous bioactive molecule. As a result, the formation of 1, 3-amino alcohols occupies a hot resarch topic in asymmetric synthesis. This review symmarizes several types of frequently-used methods and progress on synthesizing 1, 3-amino alcohols:aldol or azo-aldol condensation synthesis, transition metal catalyzed C-H activation and amination synthesis, ring-opening and addition of azocyclic compounds, and[3+2] dipolar-cycloaddition reaction etc.
Optically pure 1, 3-amino alcohol is not only the important synthon in organic synthesis, but also the core structure of numerous bioactive molecule. As a result, the formation of 1, 3-amino alcohols occupies a hot resarch topic in asymmetric synthesis. This review symmarizes several types of frequently-used methods and progress on synthesizing 1, 3-amino alcohols:aldol or azo-aldol condensation synthesis, transition metal catalyzed C-H activation and amination synthesis, ring-opening and addition of azocyclic compounds, and[3+2] dipolar-cycloaddition reaction etc.
2020, 40(5): 1150-1176
doi: 10.6023/cjoc201910019
Abstract:
Due to its high ring strain, cyclopropanes can react with a variety of unsaturated compounds to construct five- membered carbo- and hetero-cycles through[3+2] ring-expansion reaction. These five-membered compounds are key skeletons of many drugs, natural products and bioactive molecules, and are also an important class of organic intermediates which have wide applications in medicine, agriculture, chemical engineering, organic synthesis and other related areas. Recently, more and more chemists have constructed a lot of complex five-membered carbo- and hetero-cycles by using cyclopropane as a three-carbon synthon, which has promoted the rapid development of focus area. This review summarizes the most recent [3+2] ring-expansion reaction of cyclopropanes with compounds containing unsaturated bonds such as olefins, aldehydes, ketones and nitriles in the past decade. Moreover, the prospects of future development are also discussed.
Due to its high ring strain, cyclopropanes can react with a variety of unsaturated compounds to construct five- membered carbo- and hetero-cycles through[3+2] ring-expansion reaction. These five-membered compounds are key skeletons of many drugs, natural products and bioactive molecules, and are also an important class of organic intermediates which have wide applications in medicine, agriculture, chemical engineering, organic synthesis and other related areas. Recently, more and more chemists have constructed a lot of complex five-membered carbo- and hetero-cycles by using cyclopropane as a three-carbon synthon, which has promoted the rapid development of focus area. This review summarizes the most recent [3+2] ring-expansion reaction of cyclopropanes with compounds containing unsaturated bonds such as olefins, aldehydes, ketones and nitriles in the past decade. Moreover, the prospects of future development are also discussed.
2020, 40(5): 1177-1187
doi: 10.6023/cjoc201910012
Abstract:
Cobalt is abound in the earth and has advantages of low cost and low toxicity. Cobalt complexes have been widely applied as catalysts in numerous catalytic organic reactions, in which the complexes show excellent catalytic performance and have been recognized as a very important research field. The recent progress in the application of cobalt complexes in the catalytic hydrosilylation of alkenes, alkynes, carbonyl compounds and other unsaturated double bond is summarized. Furthermore, the deficiencies of the catalysts have been discussed. At last, the future development and prospects of these complexes as catalysts are also proposed.
Cobalt is abound in the earth and has advantages of low cost and low toxicity. Cobalt complexes have been widely applied as catalysts in numerous catalytic organic reactions, in which the complexes show excellent catalytic performance and have been recognized as a very important research field. The recent progress in the application of cobalt complexes in the catalytic hydrosilylation of alkenes, alkynes, carbonyl compounds and other unsaturated double bond is summarized. Furthermore, the deficiencies of the catalysts have been discussed. At last, the future development and prospects of these complexes as catalysts are also proposed.
2020, 40(5): 1188-1205
doi: 10.6023/cjoc201910002
Abstract:
The N-arylsulfonamide group is an important moiety in medicinal chemistry because of its presence in many useful molecules with potential bioactivities. As a result, the development of synthetic routes to N-arylsulfonamides has been actively investigated. In recent years, the transition metal-catalyzed sulfonamidations of aryl halides, arylboronic acids and CAr-H bonds have extensively investigated, providing more efficient and environmentally friendly procedures for the synthesis of N-arylsulfonamides. The recent progress in the transition metal-catalyzed sulfonamidation reactions is reviewed. The aromatic substrates, transition metal-catalysts, ligands, sulfonamidating reagents, mechanisms of the sulfonamidation reactions are mainly discussed. Finally, the future development of them is also prospected.
The N-arylsulfonamide group is an important moiety in medicinal chemistry because of its presence in many useful molecules with potential bioactivities. As a result, the development of synthetic routes to N-arylsulfonamides has been actively investigated. In recent years, the transition metal-catalyzed sulfonamidations of aryl halides, arylboronic acids and CAr-H bonds have extensively investigated, providing more efficient and environmentally friendly procedures for the synthesis of N-arylsulfonamides. The recent progress in the transition metal-catalyzed sulfonamidation reactions is reviewed. The aromatic substrates, transition metal-catalysts, ligands, sulfonamidating reagents, mechanisms of the sulfonamidation reactions are mainly discussed. Finally, the future development of them is also prospected.
2020, 40(5): 1206-1231
doi: 10.6023/cjoc201911004
Abstract:
Hypochlorous acid (HClO) and sodium hypochlorite (NaClO) exist widely in living organisms and environment and is closely related to the health or disease of living organisms. In recent years, in order to reveal the effect and mechanism of HClO on living organisms, many HClO colorimetric and fluorimetric probes have been designed and applied to the detection HClO or ClO- in environment or living organisms due to their sensitivity, rapidity, high selectivity and real-time monitoring. According to the different recognition mechanism of probes for HClO, HCO colorimetric fluorescent probes are divided into five categories. The design, characteristics and practical application of hypochlorite colorimetric fluorescent probes in the past five years are summarized and evaluated.
Hypochlorous acid (HClO) and sodium hypochlorite (NaClO) exist widely in living organisms and environment and is closely related to the health or disease of living organisms. In recent years, in order to reveal the effect and mechanism of HClO on living organisms, many HClO colorimetric and fluorimetric probes have been designed and applied to the detection HClO or ClO- in environment or living organisms due to their sensitivity, rapidity, high selectivity and real-time monitoring. According to the different recognition mechanism of probes for HClO, HCO colorimetric fluorescent probes are divided into five categories. The design, characteristics and practical application of hypochlorite colorimetric fluorescent probes in the past five years are summarized and evaluated.
2020, 40(5): 1232-1238
doi: 10.6023/cjoc201909037
Abstract:
Based on 3, 4, 5-trihydroxybenzohydrazide and 4-methyl-7-hydroxy-8-aldehyde coumarin, a simple sensor FQ was designed and synthesized, which showed the "turn-on" fluorescence response to cyanide in an aqueous medium. The hydrazide, hydroxyl and phenolic hydroxyl groups on FQ were receptor unit, and coumarin plays a role in signal reporting. The electron withdrawing group (hydroxyl group) of FQ prevented its intramolecular charge transfer with coumarin group. When CN- was added, the protons of hydrazide and hydroxyl group were removed by protonation in two-step, so that intramolecular charge transfer (ICT) between phenyl group and coumarin group could be carried out. The mechanism of step-by-step deprotonation was confirmed by 1H NMR titration and DFT calculation. Furthermore, compared to the reported literature, FQ had a lower detection line for CN- fluorescence detection (9.92×10-8 mol·L-1). Notably sensor FQ has been successfully used to detect cyanide anions in food samples. The prepared FQ-containing test strip could be used colorimetric device for CN- detection.
Based on 3, 4, 5-trihydroxybenzohydrazide and 4-methyl-7-hydroxy-8-aldehyde coumarin, a simple sensor FQ was designed and synthesized, which showed the "turn-on" fluorescence response to cyanide in an aqueous medium. The hydrazide, hydroxyl and phenolic hydroxyl groups on FQ were receptor unit, and coumarin plays a role in signal reporting. The electron withdrawing group (hydroxyl group) of FQ prevented its intramolecular charge transfer with coumarin group. When CN- was added, the protons of hydrazide and hydroxyl group were removed by protonation in two-step, so that intramolecular charge transfer (ICT) between phenyl group and coumarin group could be carried out. The mechanism of step-by-step deprotonation was confirmed by 1H NMR titration and DFT calculation. Furthermore, compared to the reported literature, FQ had a lower detection line for CN- fluorescence detection (9.92×10-8 mol·L-1). Notably sensor FQ has been successfully used to detect cyanide anions in food samples. The prepared FQ-containing test strip could be used colorimetric device for CN- detection.
2020, 40(5): 1239-1245
doi: 10.6023/cjoc201911015
Abstract:
Intracellular small-molecule thiols, such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play pivotal roles in several physiological and pathological processes. A bodipy-nitroolefin-conjugated fluorescent probe based on photoinduced electron transfer (PET) mechanism was designed and successfully constructed. The probe selectively responds to biothiols by Michael addition reaction of the sulfhydryl group to the double bond activated by Nitroolefin moiety and gives an off-on fluorescent response. The fluorescence detection limit for GSH was calculated to be 11×10-9 mol/L. The results of fluorescence confocal imaging indicated that the probe has appreciable cell permeability and can serve as a fluorescent probe for detecting biothiols in living cells and zebrafish.
Intracellular small-molecule thiols, such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play pivotal roles in several physiological and pathological processes. A bodipy-nitroolefin-conjugated fluorescent probe based on photoinduced electron transfer (PET) mechanism was designed and successfully constructed. The probe selectively responds to biothiols by Michael addition reaction of the sulfhydryl group to the double bond activated by Nitroolefin moiety and gives an off-on fluorescent response. The fluorescence detection limit for GSH was calculated to be 11×10-9 mol/L. The results of fluorescence confocal imaging indicated that the probe has appreciable cell permeability and can serve as a fluorescent probe for detecting biothiols in living cells and zebrafish.
2020, 40(5): 1246-1250
doi: 10.6023/cjoc201911022
Abstract:
A near-infrared region (NIR) fluoroborodipyrrole fluorescent dye (QBOP-lys) was synthesized through Knoevenagel condensation reaction. The D-A configuration of the QBOP-lys dyes was conjugated by two p-morpholine styrene with one 8-hydroxyquino BODIPY structure. This QBOP-lys dye has been characterized by NMR and high resolution mass spectrometry. In dimethyl sulfoxide (DMSO) solution, the maximum absorption wavelength of QBOP-lys was at 698 nm and its molar extinction coefficient was 5.9×104 L·mol-1·cm-1, the maximum emission wavelength was at 770 nm and its stokes shift was 73 nm. Besides that, QBOP-lys has been prepared as water-soluble nano-silica fluorescent nanoparticles (QBOP-lys/SiO2). The maximum emission wavelength of QBOP-lys/SiO2 was 726 nm in pure aqueous solution and the fluorescence quantum of QBOP-lys/SiO2 was 0.33, which made QBOP-lys have good near-infrared fluorescence emission characteristics in organic solvents or pure water. On the other hand, QBOP-lys was also used for lysosomal imaging in SGC-7901 cells, the colocalization coefficient of dye QBOP-lys with Lyso-Tracker Green, a commercial lysosomal green dye, was up to 0.9. Besides that, after QBOP-lys incubate with cells SGC-7901 for 48 h, it could still maintain good fluorescence imaging performance which could be used for long-term tracking imaging. The spectroscopy experiments and cell experiments both proved that dye QBOP-lys was a very promising NIR dye in future application.
A near-infrared region (NIR) fluoroborodipyrrole fluorescent dye (QBOP-lys) was synthesized through Knoevenagel condensation reaction. The D-A configuration of the QBOP-lys dyes was conjugated by two p-morpholine styrene with one 8-hydroxyquino BODIPY structure. This QBOP-lys dye has been characterized by NMR and high resolution mass spectrometry. In dimethyl sulfoxide (DMSO) solution, the maximum absorption wavelength of QBOP-lys was at 698 nm and its molar extinction coefficient was 5.9×104 L·mol-1·cm-1, the maximum emission wavelength was at 770 nm and its stokes shift was 73 nm. Besides that, QBOP-lys has been prepared as water-soluble nano-silica fluorescent nanoparticles (QBOP-lys/SiO2). The maximum emission wavelength of QBOP-lys/SiO2 was 726 nm in pure aqueous solution and the fluorescence quantum of QBOP-lys/SiO2 was 0.33, which made QBOP-lys have good near-infrared fluorescence emission characteristics in organic solvents or pure water. On the other hand, QBOP-lys was also used for lysosomal imaging in SGC-7901 cells, the colocalization coefficient of dye QBOP-lys with Lyso-Tracker Green, a commercial lysosomal green dye, was up to 0.9. Besides that, after QBOP-lys incubate with cells SGC-7901 for 48 h, it could still maintain good fluorescence imaging performance which could be used for long-term tracking imaging. The spectroscopy experiments and cell experiments both proved that dye QBOP-lys was a very promising NIR dye in future application.
2020, 40(5): 1251-1256
doi: 10.6023/cjoc201912026
Abstract:
A novel acylhydrazone derivative (i.e. fluorescence probe L) was designed and synthesized based on 7-hydroxy- tetrahydroquinoxaline-6-formaldehyde. Probe L can recognize for Al3+ with highly selectivity in DMSO/Tris (V:V=7:3) solution. When Al3+ is added into the solution of L, the fluorescence color of solution changes from non-fluorescence to purple red fluorescence, and the maximum emission wavelength of L is 640 nm within range of the near-infrared. Probe L possesses a large Stokes shift (170 nm) and the detection limit of L is 0.521 μmol/L. In addition, L can detect Al3+ in the real water samples and imaging for Al3+ in MCF-7 cells.
A novel acylhydrazone derivative (i.e. fluorescence probe L) was designed and synthesized based on 7-hydroxy- tetrahydroquinoxaline-6-formaldehyde. Probe L can recognize for Al3+ with highly selectivity in DMSO/Tris (V:V=7:3) solution. When Al3+ is added into the solution of L, the fluorescence color of solution changes from non-fluorescence to purple red fluorescence, and the maximum emission wavelength of L is 640 nm within range of the near-infrared. Probe L possesses a large Stokes shift (170 nm) and the detection limit of L is 0.521 μmol/L. In addition, L can detect Al3+ in the real water samples and imaging for Al3+ in MCF-7 cells.
2020, 40(5): 1257-1265
doi: 10.6023/cjoc201911036
Abstract:
Sulfuric acid efficiently catalyzes the direct substitution of the hydroxyl group of propargylic alcohols with a variety of C- and O-based nucleophiles to aid C-C and C-O bond formation. The reactions can be performed in an undried solvent under air atmosphere to obtain the desired products in good yields. In most cases, the reaction proceeds to completion in 1 min at room temperature.
Sulfuric acid efficiently catalyzes the direct substitution of the hydroxyl group of propargylic alcohols with a variety of C- and O-based nucleophiles to aid C-C and C-O bond formation. The reactions can be performed in an undried solvent under air atmosphere to obtain the desired products in good yields. In most cases, the reaction proceeds to completion in 1 min at room temperature.
2020, 40(5): 1266-1274
doi: 10.6023/cjoc201908007
Abstract:
A series of thiazolo[3, 2-a]pyrimidine derivatives were synthesized from the reaction of α-bromoacetophenone, aromatic aldehyde, malononitrile and thiourea which was catalyzed by Tröger's base derivative 5, 12-dimethyl-3, 10-diphenyl- bis-1H-pyrazol[b, f] [4 , 5 ]-1, 5- diazadicyclo[3.3.1]-2, 6-octadiene (1). The reaction mechanism was discussed by the 1H NMR analysis and chemical experiments. The pharmacological activity results of the products indicated that most of products showed high inhibitory on one or more cancer cells in human hepatocarcinoma cell (HepG2), human non-small cell lung cancer cell (247) and human non-small cell lung cancer cell (A549) in vitro. And seven products have antibacterial activity against the methicillin-resistant Staphylococcus aureus. These results showed the great potential of these compounds in drug development.
A series of thiazolo[3, 2-a]pyrimidine derivatives were synthesized from the reaction of α-bromoacetophenone, aromatic aldehyde, malononitrile and thiourea which was catalyzed by Tröger's base derivative 5, 12-dimethyl-3, 10-diphenyl- bis-1H-pyrazol[b, f] [
2020, 40(5): 1275-1280
doi: 10.6023/cjoc201911040
Abstract:
Subergorgic acid (1), a cyclopentapentalane sesquiterpenoid and potential reversible cholinesterase inhibitor, and its analogue 2-deoxy-2β-hydroxysubergorgic acid (2) were first isolated from soft coral-associated symbiotic and epiphytic fungus Aspergillus sp. EGF15-0-3. Their structures were established by NMR and HRESIMS spectroscopic data. According to the strategy of one strain many compounds (OSMAC) and eutrophic culture, Global Natural Products Molecular Networking (GNPS) was applied to detect the presence of compounds 1 and 2 in 23 different media for optimal medium compositions. As a result, compound 1 was found in 6 different media besides potato dextrose broth (PDB) medium, the contents of 2 were different in the solid and liquid media, and the best medium for compounds 1 and 2 was GPY+CaCO3. It was demonstrated that the soft coral-associated symbiotic and epiphytic fungus Aspergillus sp. EGF15-0-3 was the microbiological producer of compounds 1 and 2. This work provided strong evidence to support the hypothesis that novel and bioactive secondary metabolites produced by marine invertebrates often come from endogenetic, epiphytic, symbiotic or environmental microorganisms.
Subergorgic acid (1), a cyclopentapentalane sesquiterpenoid and potential reversible cholinesterase inhibitor, and its analogue 2-deoxy-2β-hydroxysubergorgic acid (2) were first isolated from soft coral-associated symbiotic and epiphytic fungus Aspergillus sp. EGF15-0-3. Their structures were established by NMR and HRESIMS spectroscopic data. According to the strategy of one strain many compounds (OSMAC) and eutrophic culture, Global Natural Products Molecular Networking (GNPS) was applied to detect the presence of compounds 1 and 2 in 23 different media for optimal medium compositions. As a result, compound 1 was found in 6 different media besides potato dextrose broth (PDB) medium, the contents of 2 were different in the solid and liquid media, and the best medium for compounds 1 and 2 was GPY+CaCO3. It was demonstrated that the soft coral-associated symbiotic and epiphytic fungus Aspergillus sp. EGF15-0-3 was the microbiological producer of compounds 1 and 2. This work provided strong evidence to support the hypothesis that novel and bioactive secondary metabolites produced by marine invertebrates often come from endogenetic, epiphytic, symbiotic or environmental microorganisms.
2020, 40(5): 1281-1289
doi: 10.6023/cjoc201912002
Abstract:
A novel synthetic route for the total syntheses of 1-benzoyl-3, 4-dihydroisoquinoline alkaloids was developed. Nelumstemine was synthesized for the first time via 6 steps in 50% overall yield starting from 3, 4-dimethoxybenzaldehyde, and longifolonine was also synthesized for the first time via 9 steps in 35% overall yield starting from vanillin. The key step of these total syntheses is photo-oxidation of 1-benzyl-3, 4-dihydroisoquinolines to 1-benzoyl-3, 4-dihydroisoquinolines by air under visible-light irradiation at room temperature. The unique mild photo-oxidation of 1-benzyl-3, 4-dihydro-isoquinolines has been studied in detail.
A novel synthetic route for the total syntheses of 1-benzoyl-3, 4-dihydroisoquinoline alkaloids was developed. Nelumstemine was synthesized for the first time via 6 steps in 50% overall yield starting from 3, 4-dimethoxybenzaldehyde, and longifolonine was also synthesized for the first time via 9 steps in 35% overall yield starting from vanillin. The key step of these total syntheses is photo-oxidation of 1-benzyl-3, 4-dihydroisoquinolines to 1-benzoyl-3, 4-dihydroisoquinolines by air under visible-light irradiation at room temperature. The unique mild photo-oxidation of 1-benzyl-3, 4-dihydro-isoquinolines has been studied in detail.
2020, 40(5): 1290-1296
doi: 10.6023/cjoc201911020
Abstract:
A highly selective and efficient copper-catalyzed sequential approach for the one-pot two-step synthesis of unsymmetrical 1, 4-diamino-2-butynes from propiolic acid, secondary alkylamine, aldehyde and formaldehyde solution has been developed. The process of this reaction was involved in the generation of key intermediate propargylamines which were obtained via decarboxylative A3-coupling reaction. After that, the intermediate propargylamines would react with in situ formed iminium ions to give the cross-coupling target products in moderate to excellent yields under microwave irradiation.
A highly selective and efficient copper-catalyzed sequential approach for the one-pot two-step synthesis of unsymmetrical 1, 4-diamino-2-butynes from propiolic acid, secondary alkylamine, aldehyde and formaldehyde solution has been developed. The process of this reaction was involved in the generation of key intermediate propargylamines which were obtained via decarboxylative A3-coupling reaction. After that, the intermediate propargylamines would react with in situ formed iminium ions to give the cross-coupling target products in moderate to excellent yields under microwave irradiation.
2020, 40(5): 1297-1304
doi: 10.6023/cjoc201911024
Abstract:
4-Alkyl Hasntzch esters are good alkyl radical storage. The preparation of multisubstituted α, β-unsaturated carboxylic acid esters under photocatalytic redox conditions by 4-alkyl Hantzsch esters and Baylis-Hillman adducts was investigated. The reaction conditions are mild and no additional additives are required. The coupling products were obtained in moderate to good yields.
4-Alkyl Hasntzch esters are good alkyl radical storage. The preparation of multisubstituted α, β-unsaturated carboxylic acid esters under photocatalytic redox conditions by 4-alkyl Hantzsch esters and Baylis-Hillman adducts was investigated. The reaction conditions are mild and no additional additives are required. The coupling products were obtained in moderate to good yields.
2020, 40(5): 1305-1309
doi: 10.6023/cjoc201910028
Abstract:
On the basis of density functional theory, theoretical calculation is conducted to obtain the free energy barriers of the reaction path, which may exist in the process of propylene epoxidation with co-reductant acrolein, propanal, crotonaldehyde, N-butyl aldehyde and isobutyl aldehyde respectively. And the optimal reaction path was determined to be free radical addition of peroxy acyl and propylene through analysis and comparison. In addition, the conclusion that auto-oxidation process of aldehydes and the decarboxylation in the reaction process have a certain influence on the epoxidation reaction can be conducted, and the results are in good consistent with the experimental data. It has a certain guiding effect on the choosing of co-reducing aldehydes.
On the basis of density functional theory, theoretical calculation is conducted to obtain the free energy barriers of the reaction path, which may exist in the process of propylene epoxidation with co-reductant acrolein, propanal, crotonaldehyde, N-butyl aldehyde and isobutyl aldehyde respectively. And the optimal reaction path was determined to be free radical addition of peroxy acyl and propylene through analysis and comparison. In addition, the conclusion that auto-oxidation process of aldehydes and the decarboxylation in the reaction process have a certain influence on the epoxidation reaction can be conducted, and the results are in good consistent with the experimental data. It has a certain guiding effect on the choosing of co-reducing aldehydes.
2020, 40(5): 1310-1315
doi: 10.6023/cjoc201912001
Abstract:
Amination using N-fluorobenzenesulfonimide (NFSI) as nitrogen source has become an important route to prepare amines. However, there are few methods to prepare N-vinyl sulfonimides using NFSI as nitrogen source. In the presence of Na2HPO4, the hydroamination of propiolates or propiolamides with N-fluorobenzenesulfonimide (NFSI) was realized, where Ag2CO3 and 1, 10-phenanthroline derivatives were added as catalysts. It leads to N-vinyldibenzenesulfonimides in high selectivity of Z isomers in the yields of 35%~71%.
Amination using N-fluorobenzenesulfonimide (NFSI) as nitrogen source has become an important route to prepare amines. However, there are few methods to prepare N-vinyl sulfonimides using NFSI as nitrogen source. In the presence of Na2HPO4, the hydroamination of propiolates or propiolamides with N-fluorobenzenesulfonimide (NFSI) was realized, where Ag2CO3 and 1, 10-phenanthroline derivatives were added as catalysts. It leads to N-vinyldibenzenesulfonimides in high selectivity of Z isomers in the yields of 35%~71%.
2020, 40(5): 1345-1354
doi: 10.6023/cjoc201911012
Abstract:
A series of novel derivatives containing triazolo-thiadiazole moiety have been synthesized by structural modifications on a lead disruptor of telomeric silencing 1-like (DOT1L) inhibitor 8. All the compounds have been evaluated for their DOT1L inhibitory activities at the concentration of 50 μmol/L. The results showed that the tested compounds showed certain DOT1L inhibitory activities. Among them, N, N-dimethyl-4-(6-methyl-[1, 2, 4]triazolo[3, 4-b] [1, 3, 4]thiadiazol-3-yl)aniline (14b) and (R)-tert-butyl (1-((3-(4-(dimethylamino)phenyl)-[1, 2, 4]triazolo[3, 4-b] [1, 3, 4]thiadiazol-6-yl)methyl)-piperidin-3-yl)carba- mate (16a) were the best ones with IC50 values of 7.37 and 7.84 μmol/L, respectively, near that of the positive control 8. The structure-activity analysis showed that when the triazolo-thiadiazole moiety occupied the binding-site of S-adenosylmethionine (SAM) in DOT1L and R1 group was 4-N, N-dimethyl, the hydrophobic substituents as the tailed R2 groups would be accommodated into the DOT1L binding site, and the sizes of the substituents seemed no effects on their DOT1L inhibitory activities of the compounds.
A series of novel derivatives containing triazolo-thiadiazole moiety have been synthesized by structural modifications on a lead disruptor of telomeric silencing 1-like (DOT1L) inhibitor 8. All the compounds have been evaluated for their DOT1L inhibitory activities at the concentration of 50 μmol/L. The results showed that the tested compounds showed certain DOT1L inhibitory activities. Among them, N, N-dimethyl-4-(6-methyl-[1, 2, 4]triazolo[3, 4-b] [1, 3, 4]thiadiazol-3-yl)aniline (14b) and (R)-tert-butyl (1-((3-(4-(dimethylamino)phenyl)-[1, 2, 4]triazolo[3, 4-b] [1, 3, 4]thiadiazol-6-yl)methyl)-piperidin-3-yl)carba- mate (16a) were the best ones with IC50 values of 7.37 and 7.84 μmol/L, respectively, near that of the positive control 8. The structure-activity analysis showed that when the triazolo-thiadiazole moiety occupied the binding-site of S-adenosylmethionine (SAM) in DOT1L and R1 group was 4-N, N-dimethyl, the hydrophobic substituents as the tailed R2 groups would be accommodated into the DOT1L binding site, and the sizes of the substituents seemed no effects on their DOT1L inhibitory activities of the compounds.
2020, 40(5): 1316-1322
doi: 10.6023/cjoc201912003
Abstract:
In this paper, copper nanoparticles (Cu NPs) were synthesized from copper sulfate by hydrothermal method using hydrazine hydrate as reducing agent. The obtained catalyst was characterized by transmission electron microscope (TEM) and X-ray diffraction (XRD), and successfully used as heterogeneous catalyst to promote the three-component coupling reaction of phenylacetylene, amine and aldehyde in solvent-free. Under Cu NPs (10 mol%), 110℃ and reaction time 10 h, the catalyst exhibits excellent catalytic activity with 88% yield. It is worth noting that the catalyst system can maintain high catalytic activity with only a slight decrease after 4 cycles (all isolated yields >84%). A propargylamine synthetic method by three-component coupling reaction was provided possessing the advantages of simple post-treatment procedure, solvent-free, extensive substrate range and good reusability of catalyst.
In this paper, copper nanoparticles (Cu NPs) were synthesized from copper sulfate by hydrothermal method using hydrazine hydrate as reducing agent. The obtained catalyst was characterized by transmission electron microscope (TEM) and X-ray diffraction (XRD), and successfully used as heterogeneous catalyst to promote the three-component coupling reaction of phenylacetylene, amine and aldehyde in solvent-free. Under Cu NPs (10 mol%), 110℃ and reaction time 10 h, the catalyst exhibits excellent catalytic activity with 88% yield. It is worth noting that the catalyst system can maintain high catalytic activity with only a slight decrease after 4 cycles (all isolated yields >84%). A propargylamine synthetic method by three-component coupling reaction was provided possessing the advantages of simple post-treatment procedure, solvent-free, extensive substrate range and good reusability of catalyst.
2020, 40(5): 1323-1330
doi: 10.6023/cjoc201910038
Abstract:
A green and efficient nucleophilic addition reaction of trifluoromethyl ketone with pyrazolone was developed under "on water" conditions, affording pyrazolone substituted tertiary trifluoromethyl alcohols in high yields. The advantages of being catalyst-free, column chromatography-free, environmentally benign and easy workup make it a promising method for preparation of a variety of pyrazolone substituted tertiary trifluoromethyl alcohols.
A green and efficient nucleophilic addition reaction of trifluoromethyl ketone with pyrazolone was developed under "on water" conditions, affording pyrazolone substituted tertiary trifluoromethyl alcohols in high yields. The advantages of being catalyst-free, column chromatography-free, environmentally benign and easy workup make it a promising method for preparation of a variety of pyrazolone substituted tertiary trifluoromethyl alcohols.
2020, 40(5): 1331-1336
doi: 10.6023/cjoc201911010
Abstract:
In this paper, a convenient method for multi-component one-pot synthesis of N, O-acetal compounds was developed, using aromatic aldehyde, urea and alcohol as materials, alcohol also as solvent and D-proline as catalyst. A series of N, O-acetal compounds were synthesized in good yields after reacting for 30 h at room temperature.
In this paper, a convenient method for multi-component one-pot synthesis of N, O-acetal compounds was developed, using aromatic aldehyde, urea and alcohol as materials, alcohol also as solvent and D-proline as catalyst. A series of N, O-acetal compounds were synthesized in good yields after reacting for 30 h at room temperature.
2020, 40(5): 1337-1344
doi: 10.6023/cjoc201911029
Abstract:
The cyclization reaction between 2-(arylvinyl)aniline and acetophenone in presence of iodine was reported, which offered an efficient and cost effective strategy to generate 2-acylquinoline derivatives under mild and metal-free conditions.
The cyclization reaction between 2-(arylvinyl)aniline and acetophenone in presence of iodine was reported, which offered an efficient and cost effective strategy to generate 2-acylquinoline derivatives under mild and metal-free conditions.
2020, 40(5): 1355-1360
doi: 10.6023/cjoc202001005
Abstract:
A new and efficient approach has been developed to synthesize 2-substituted acylamino naphtho[2, 1-d]thiazole compounds through the reaction between 3-(2-naphthyl)-1-substituted acylthiourea and manganese(Ⅲ) acetate under ambient air. This reaction has the advantage of simple operation, high atom economy, environmentally friendly, and cheap reagents.
A new and efficient approach has been developed to synthesize 2-substituted acylamino naphtho[2, 1-d]thiazole compounds through the reaction between 3-(2-naphthyl)-1-substituted acylthiourea and manganese(Ⅲ) acetate under ambient air. This reaction has the advantage of simple operation, high atom economy, environmentally friendly, and cheap reagents.
2020, 40(5): 1361-1366
doi: 10.6023/cjoc201912014
Abstract:
Due to the coordination-unsaturation feature of d8 and d10 transition metals, their unique electronic structures and easy formation of metal-metal bonds make them exhibit special photophysical and photochemical properties. The optical properties of luminescent molecules can be regulated through host-guest interactions. In order to further explore the effect of host-guest interaction on the optical properties of d8 and d10 transition metal complexes, the member with the largest cavity in the macrocyclic family of cucurbit[n]uril (CB[n], n=5~8, 10)-CB[10] was selected as host. The changes in photophysical properties of such water-soluble planar transition metal complexes after entering the host cavity were studied by means of UV/Vis, fluorescence, 1H NMR and mass spectra. The results show that the cavity of CB[10] can accommodate multiple Pt(Ⅱ) complex molecules. By enhancing the π-π interaction between guest molecules in the cavity of CB[10], the distance between metal atoms was shortened, leading the formation of metal-metal interactions in the water phase. Encapsulation of Ir(Ⅲ)complex in CB[10] causes the formation of excimer. In addition, strong metal-metal interactions between Rh(Ⅰ) complex molecules were weakened after the guest went into CB[10], which should be attributed to the formation of 1:1 host-guest complex. The introduction of host-guest chemistry in regulating photophysical properties of d8 and d10 metal complexes would further expand the application of transition metal complexes in a wider range of fields.
Due to the coordination-unsaturation feature of d8 and d10 transition metals, their unique electronic structures and easy formation of metal-metal bonds make them exhibit special photophysical and photochemical properties. The optical properties of luminescent molecules can be regulated through host-guest interactions. In order to further explore the effect of host-guest interaction on the optical properties of d8 and d10 transition metal complexes, the member with the largest cavity in the macrocyclic family of cucurbit[n]uril (CB[n], n=5~8, 10)-CB[10] was selected as host. The changes in photophysical properties of such water-soluble planar transition metal complexes after entering the host cavity were studied by means of UV/Vis, fluorescence, 1H NMR and mass spectra. The results show that the cavity of CB[10] can accommodate multiple Pt(Ⅱ) complex molecules. By enhancing the π-π interaction between guest molecules in the cavity of CB[10], the distance between metal atoms was shortened, leading the formation of metal-metal interactions in the water phase. Encapsulation of Ir(Ⅲ)complex in CB[10] causes the formation of excimer. In addition, strong metal-metal interactions between Rh(Ⅰ) complex molecules were weakened after the guest went into CB[10], which should be attributed to the formation of 1:1 host-guest complex. The introduction of host-guest chemistry in regulating photophysical properties of d8 and d10 metal complexes would further expand the application of transition metal complexes in a wider range of fields.
2020, 40(5): 1372-1377
doi: 10.6023/cjoc201912010
Abstract:
The hydrodehalogenation of halogenated organic compounds which have brought serious pollution to the environment can not only transform them into other usefull chemicals, but also reduce their pollution in the field of environment. A Pd-catalyzed hydrodehalogenation of o-triazole aryl halides is introduced, taking Pd/C as catalyst and Et3N as base, reductant and hydrogen source. This strategy is highlighted by appealing features such as simple reaction condition, recyclable catalyst, and good yield etc.
The hydrodehalogenation of halogenated organic compounds which have brought serious pollution to the environment can not only transform them into other usefull chemicals, but also reduce their pollution in the field of environment. A Pd-catalyzed hydrodehalogenation of o-triazole aryl halides is introduced, taking Pd/C as catalyst and Et3N as base, reductant and hydrogen source. This strategy is highlighted by appealing features such as simple reaction condition, recyclable catalyst, and good yield etc.
2020, 40(5): 1384-1387
doi: 10.6023/cjoc201910003
Abstract:
3-Selenocyanateindole derivatives have potential application in drug research due to their good biological activity. Until now, many methods for the synthesis of 3-selenocyanateindoles have been reported. However, drawbacks still exist, such as harsh reaction conditions, low yields and poor functional groups tolerance. A series of 3-selenocyanateindoles have been synthesized via the microwave-assisted 3-selenocyanation of indole derivatives by using 25 mol% iodine as catalyst, affording the corresponding products in good yields. Compared with the previous methods, this protocol has the advantages of rapid reaction, high yields and good atomic economy, providing an efficient route to 3-selenocyanateindole derivatives.
3-Selenocyanateindole derivatives have potential application in drug research due to their good biological activity. Until now, many methods for the synthesis of 3-selenocyanateindoles have been reported. However, drawbacks still exist, such as harsh reaction conditions, low yields and poor functional groups tolerance. A series of 3-selenocyanateindoles have been synthesized via the microwave-assisted 3-selenocyanation of indole derivatives by using 25 mol% iodine as catalyst, affording the corresponding products in good yields. Compared with the previous methods, this protocol has the advantages of rapid reaction, high yields and good atomic economy, providing an efficient route to 3-selenocyanateindole derivatives.
2020, 40(5): 1388-1393
doi: 10.6023/cjoc201910030
Abstract:
The 1, 1-dichloroalkene structural unit is found in many natural products. 1, 1-Dichloroalkenes are important intermediates, which have been widely used in the synthesis of alkynes, halogenated acetylenes and aromatic compounds. In this paper, a new dichloroolefinating reagent, dichloromethyl 2-pyridyl sulfone, was reported. 1, 1-Dichloroalkenes can be conveniently obtained from the reaction of dichloromethyl 2-pyridyl sulfone with aromatic aldehydes using t-BuOK as base. This method has the advantage of operational simplicity, usage of easily available reagents and easy purification, which may find applications in organic synthesis.
The 1, 1-dichloroalkene structural unit is found in many natural products. 1, 1-Dichloroalkenes are important intermediates, which have been widely used in the synthesis of alkynes, halogenated acetylenes and aromatic compounds. In this paper, a new dichloroolefinating reagent, dichloromethyl 2-pyridyl sulfone, was reported. 1, 1-Dichloroalkenes can be conveniently obtained from the reaction of dichloromethyl 2-pyridyl sulfone with aromatic aldehydes using t-BuOK as base. This method has the advantage of operational simplicity, usage of easily available reagents and easy purification, which may find applications in organic synthesis.
2020, 40(5): 1367-1371
doi: 10.6023/cjoc201912012
Abstract:
One new compound, named hypoxone A (1), together with two new natural products 4, 8-dimethoxy-1-naphthol (2) and 1'-hydroxy-4', 8, 8'-trimethoxy[2, 2']binaphthalenyl-1, 4-dione (3), and fourteen known derivatives 4~17 were isolated from the broth extract of the marine fungus Hypoxylon rubiginosum FS521, which was isolated from a deep-sea sediment sample. Their structures were elucidated by interpretation of spectroscopic analysis and comparison with previously published data for the known ones. Moreover, compounds 1~4 were evaluated for their in vitro cytotoxic activities against SF-268, MCF-7, HepG-2, and A549 tumor cell lines, and compound 3 exhibited potent cytotoxic activity with IC50 values of 1.85, 3.21, 2.53, and 5.09 mmol·L-1, respectively.
One new compound, named hypoxone A (1), together with two new natural products 4, 8-dimethoxy-1-naphthol (2) and 1'-hydroxy-4', 8, 8'-trimethoxy[2, 2']binaphthalenyl-1, 4-dione (3), and fourteen known derivatives 4~17 were isolated from the broth extract of the marine fungus Hypoxylon rubiginosum FS521, which was isolated from a deep-sea sediment sample. Their structures were elucidated by interpretation of spectroscopic analysis and comparison with previously published data for the known ones. Moreover, compounds 1~4 were evaluated for their in vitro cytotoxic activities against SF-268, MCF-7, HepG-2, and A549 tumor cell lines, and compound 3 exhibited potent cytotoxic activity with IC50 values of 1.85, 3.21, 2.53, and 5.09 mmol·L-1, respectively.
2020, 40(5): 1378-1383
doi: 10.6023/cjoc201911027
Abstract:
The asymmetric Michael addition of 1-acetylindolin-3-ones to β, γ-unsaturated α-keto esters catalyzed by bifunctional thioureas has been developed. Enantio-pure 2-substituted indolin-3-one derivatives were obtained easily in excellent yields (up to 99%) with good diastereoselectivity (up to 10:1) and excellent enantioselectivities (up to 99.5%), which would be useful for the chiral synthesis of indole-related compounds.
The asymmetric Michael addition of 1-acetylindolin-3-ones to β, γ-unsaturated α-keto esters catalyzed by bifunctional thioureas has been developed. Enantio-pure 2-substituted indolin-3-one derivatives were obtained easily in excellent yields (up to 99%) with good diastereoselectivity (up to 10:1) and excellent enantioselectivities (up to 99.5%), which would be useful for the chiral synthesis of indole-related compounds.
2020, 40(5): 1394-1395
doi: 10.6023/cjoc202000022
Abstract:
2020, 40(5): 1396-1397
doi: 10.6023/cjoc202000023
Abstract:
2020, 40(5): 1398-1399
doi: 10.6023/cjoc202000024
Abstract:
2020, 40(5): 1400-1401
doi: 10.6023/cjoc202000025
Abstract:
2020, 40(5): 1402-1403
doi: 10.6023/cjoc202000026
Abstract:
2020, 40(5): 1404-1405
doi: 10.6023/cjoc202000027
Abstract:
2020, 40(5): 1406-1407
doi: 10.6023/cjoc202000028
Abstract:
