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2018 Volume 38 Issue 7
2018, 38(7): 1569-1585
doi: 10.6023/cjoc201801041
Abstract:
The difluoromethyl functional group (CF2H) which has strong lipophilic and electron-withdrawing properties can significantly enhance the physiological activity of organic molecules. The applications of CF2H-containing compounds in the fields of drugs, agrochemicals and so on have attracted great attention of many research groups. Therefore, the development of effective and general methodologies for the selective incorporation of difluoromethyl groups has become one of the hotspots in the field of organic chemistry. Recently, new difluoromethylation reagents and methods that were able to efficiently incorporate the difluoromethyl group under mild conditions have been developed rapidly, that pave the way for the facile introduction of difluoromethyl group into site-specific positions of the target molecules. In this paper, we will first briefly introduce some organic molecules with different functional groups which can be difluoromethylated, and then focus on the development of the recent high-performance difluoromethylation reagents, new reactions and catalysts. Finally, we will discuss the remaining problems and challenges in this particular field.
The difluoromethyl functional group (CF2H) which has strong lipophilic and electron-withdrawing properties can significantly enhance the physiological activity of organic molecules. The applications of CF2H-containing compounds in the fields of drugs, agrochemicals and so on have attracted great attention of many research groups. Therefore, the development of effective and general methodologies for the selective incorporation of difluoromethyl groups has become one of the hotspots in the field of organic chemistry. Recently, new difluoromethylation reagents and methods that were able to efficiently incorporate the difluoromethyl group under mild conditions have been developed rapidly, that pave the way for the facile introduction of difluoromethyl group into site-specific positions of the target molecules. In this paper, we will first briefly introduce some organic molecules with different functional groups which can be difluoromethylated, and then focus on the development of the recent high-performance difluoromethylation reagents, new reactions and catalysts. Finally, we will discuss the remaining problems and challenges in this particular field.
2018, 38(7): 1586-1595
doi: 10.6023/cjoc201802021
Abstract:
As a kind of low toxicity, environmentally friendly, high reaction activity reagent, hypervalent iodine compounds have received the widespread attention. Acyclic diaryl iodonium salt as aryl cationic reagent, has an important application in organic synthesis. Under mild conditions, diaryl iodonium salt can react with nucleophilic reagent, which has been one of the effective means of the arylation of heteroatom. According to the classification of chemical bond formation, the application of the acyclic diaryl iodonium salt in the arylation of heteroatom (including oxygen, nitrogen, sulfur, phosphorus, etc.) is discussed and the development direction in the field is prospected.
As a kind of low toxicity, environmentally friendly, high reaction activity reagent, hypervalent iodine compounds have received the widespread attention. Acyclic diaryl iodonium salt as aryl cationic reagent, has an important application in organic synthesis. Under mild conditions, diaryl iodonium salt can react with nucleophilic reagent, which has been one of the effective means of the arylation of heteroatom. According to the classification of chemical bond formation, the application of the acyclic diaryl iodonium salt in the arylation of heteroatom (including oxygen, nitrogen, sulfur, phosphorus, etc.) is discussed and the development direction in the field is prospected.
2018, 38(7): 1596-1607
doi: 10.6023/cjoc201801022
Abstract:
Alzheimer's disease is the leading cause of dementia, which can endanger devastating damage to memory and cognition of the elderly and eventually lead to death. Over expression of glycogen synthase kinase-3 (GSK-3) is closely related to the development and progression of Alzheimer's disease, and has become a hot field for the development of therapies for Alzheimer's disease. The GSK-3 inhibitors reported in recent five years, mainly including ATP competitive inhibitors, non-ATP competitive inhibitors, substrate competitive inhibitors, allosteric inhibitors, irreversible inhibitors are summarized and natural products, furthermore, the source, chemical structure and mechanism about GSK-3 inhibitors are introduced. Research prospects in this field are also discussed.
Alzheimer's disease is the leading cause of dementia, which can endanger devastating damage to memory and cognition of the elderly and eventually lead to death. Over expression of glycogen synthase kinase-3 (GSK-3) is closely related to the development and progression of Alzheimer's disease, and has become a hot field for the development of therapies for Alzheimer's disease. The GSK-3 inhibitors reported in recent five years, mainly including ATP competitive inhibitors, non-ATP competitive inhibitors, substrate competitive inhibitors, allosteric inhibitors, irreversible inhibitors are summarized and natural products, furthermore, the source, chemical structure and mechanism about GSK-3 inhibitors are introduced. Research prospects in this field are also discussed.
2018, 38(7): 1608-1625
doi: 10.6023/cjoc201803005
Abstract:
Michael addition and aldol reaction are among the most basic and commoly used reactions. Cascade halo-Michael/Aldol reaction can effectively improve the atomic economy and step economy of organic synthesis. After the Michael addition of α, β-unsaturated compound with halide ion (Cl-, Br-, I-), the reactive intermediate reacts with aldehyde through aldol reaction in the same reaction system. This process is called cascade halo-Michael/Aldol reaction. The cascade halo-Michael/Aldol reaction and its applications in the synthesis of related compounds according to the types of Lewis acid are introduced.
Michael addition and aldol reaction are among the most basic and commoly used reactions. Cascade halo-Michael/Aldol reaction can effectively improve the atomic economy and step economy of organic synthesis. After the Michael addition of α, β-unsaturated compound with halide ion (Cl-, Br-, I-), the reactive intermediate reacts with aldehyde through aldol reaction in the same reaction system. This process is called cascade halo-Michael/Aldol reaction. The cascade halo-Michael/Aldol reaction and its applications in the synthesis of related compounds according to the types of Lewis acid are introduced.
2018, 38(7): 1626-1637
doi: 10.6023/cjoc201801046
Abstract:
Carbon dioxide as a green and cheap C1 synthon has significant research value and industrial application prospect. In recent years, using carbon dioxide to synthesize cyclic carbamates, quinazoline-2, 4-(1H, 3H)-diones, cyclic lactones and other heterocyclic compounds have been research hotspot. Many of the heterocyclic compounds can be synthesized by reacting the carbon atom in carbon dioxide with electron deficient with nucleophiles. This review focuses on the recent intermolecular and intramolecular reactions of carbon dioxide with nucleophiles centered around nitrogen, oxygen, or carbon.
Carbon dioxide as a green and cheap C1 synthon has significant research value and industrial application prospect. In recent years, using carbon dioxide to synthesize cyclic carbamates, quinazoline-2, 4-(1H, 3H)-diones, cyclic lactones and other heterocyclic compounds have been research hotspot. Many of the heterocyclic compounds can be synthesized by reacting the carbon atom in carbon dioxide with electron deficient with nucleophiles. This review focuses on the recent intermolecular and intramolecular reactions of carbon dioxide with nucleophiles centered around nitrogen, oxygen, or carbon.
2018, 38(7): 1638-1649
doi: 10.6023/cjoc201802007
Abstract:
Transition-metal-catalyzed C—C bond cleavage has been considered as one of the most interesting subject and challenging area in organometallic chemistry. The recent progress of transition-metal-catalyzed (Rh, Ni, Pd and Ru) nitrogen atom chelation-assisted C—C activation and controlled transformation is reviewed, and the mechanisms of these C—C activation reactions are also discussed.
Transition-metal-catalyzed C—C bond cleavage has been considered as one of the most interesting subject and challenging area in organometallic chemistry. The recent progress of transition-metal-catalyzed (Rh, Ni, Pd and Ru) nitrogen atom chelation-assisted C—C activation and controlled transformation is reviewed, and the mechanisms of these C—C activation reactions are also discussed.
2018, 38(7): 1650-1655
doi: 10.6023/cjoc201801045
Abstract:
Nitroarenes are easily synthesized, highly versatile and common aromatic building blocks in organic synthesis. Recently, transition metal-catalyzed denitration-coupling of nitroarenes has attracted extensive attention. The recent advances in denitration-coupling of nitroarenes for the formation of C-X (C) bonds under transition metal-catalysis conditions are summarized.
Nitroarenes are easily synthesized, highly versatile and common aromatic building blocks in organic synthesis. Recently, transition metal-catalyzed denitration-coupling of nitroarenes has attracted extensive attention. The recent advances in denitration-coupling of nitroarenes for the formation of C-X (C) bonds under transition metal-catalysis conditions are summarized.
2018, 38(7): 1656-1662
doi: 10.6023/cjoc201803015
Abstract:
Treatment of (2, 6-F2C6H3)(2-BrC6H4)NH with 2 equiv. of nBuLi, followed by the interaction with 0.5 equiv. of PhAsCl2 and quenching with aqueous solution, afforded the new bis(amido)-arsorane ligand ((o-(N-(2, 6-2C6H3)NH)C6H4)2AsPh (denoted as H2(dfpN2As)). The interaction of H2(dfpN2As)) with 0.5 equiv. of[Fe(N(TMS)2)2]2 resulted in amine elimination and gave the bis(amido)-arsorene-iron(Ⅱ) complex[(κ-N, N, P-dfpN2As)Fe(THF)2] (3). Further treatment of 3 with the organic azide DippN3 rendered the formation of the first iminoarsorane-transition-metal complex[(κ-N, N, N-dfpN2AsNDipp)Fe(THF)] (4) as an air- and moisture-sensitive green solid. Reactivity study indicated that 4 can undergo nitrene-transfer reactions with excess amounts of 2, 6-dimethylphenylisocyanide and PPh3 to produce the nitrene-transfer products DippNCNC6H3Me2-2, 6 and Ph3PCNC6H3Me2-2, 6, respectively and the corresponding bis(amido)-arsorane-iron(Ⅱ) complexes[(κ-N, N, As-dfpN2As)Fe(CNC6H3Me2-2, 6)3] (5) and[(κ-N, N, As-dfpN2As)Fe(PPh3)] (6). These complexes were fully characterized by various spectroscopic methods. Solution magnetic susceptibility measurements and 57Fe Mössbauer spectroscopy (δ=0.88 mm/s, |ΔEQ|=1.50 mm/s; δ=0.90 mm/s, |ΔEQ|=2.53 mm/s; and δ=0.65 mm/s, |ΔEQ|=2.23 mm/s for 3, 4, and 6, respectively) indicated that 3, 4 and 6 are high-spin iron(Ⅱ) complexes, whereas the well-resolved diamagnetic NMR spectra of 5 in combination with its 57Fe Mössbauer spectrum data (δ=0.05 mm/s, |ΔEQ|=0.40 mm/s) revealed its low-spin iron(Ⅱ) nature. The molecular structures of 3~5 have been characterized by single-crystal X-ray diffraction studies. The dianionic bis(amido)-arsorane ligands in 3 and 5 chelate to the metal centers in a fac-fashion with the Fe-As distances being 0.2562(3) and 0.2293(1) nm, respectively. The dianionic bis(amido)-iminoarsorane ligand in 4 binds to the iron(Ⅱ) center in a fac-fashion. The Fe-As distance (0.285 nm) observed in 4 is longer than the sum of the covalent radii of Fe and As, indicating the absence of strong Fe-As interaction in the iminoarsorane-iron(Ⅱ) complex. Its As-N distance of 0.1752(3) nm is found comparable to those of the As-N bonds in the reported iminoarsoranes and bis(arsoranylidene) ammonium compounds.
Treatment of (2, 6-F2C6H3)(2-BrC6H4)NH with 2 equiv. of nBuLi, followed by the interaction with 0.5 equiv. of PhAsCl2 and quenching with aqueous solution, afforded the new bis(amido)-arsorane ligand ((o-(N-(2, 6-2C6H3)NH)C6H4)2AsPh (denoted as H2(dfpN2As)). The interaction of H2(dfpN2As)) with 0.5 equiv. of[Fe(N(TMS)2)2]2 resulted in amine elimination and gave the bis(amido)-arsorene-iron(Ⅱ) complex[(κ-N, N, P-dfpN2As)Fe(THF)2] (3). Further treatment of 3 with the organic azide DippN3 rendered the formation of the first iminoarsorane-transition-metal complex[(κ-N, N, N-dfpN2AsNDipp)Fe(THF)] (4) as an air- and moisture-sensitive green solid. Reactivity study indicated that 4 can undergo nitrene-transfer reactions with excess amounts of 2, 6-dimethylphenylisocyanide and PPh3 to produce the nitrene-transfer products DippNCNC6H3Me2-2, 6 and Ph3PCNC6H3Me2-2, 6, respectively and the corresponding bis(amido)-arsorane-iron(Ⅱ) complexes[(κ-N, N, As-dfpN2As)Fe(CNC6H3Me2-2, 6)3] (5) and[(κ-N, N, As-dfpN2As)Fe(PPh3)] (6). These complexes were fully characterized by various spectroscopic methods. Solution magnetic susceptibility measurements and 57Fe Mössbauer spectroscopy (δ=0.88 mm/s, |ΔEQ|=1.50 mm/s; δ=0.90 mm/s, |ΔEQ|=2.53 mm/s; and δ=0.65 mm/s, |ΔEQ|=2.23 mm/s for 3, 4, and 6, respectively) indicated that 3, 4 and 6 are high-spin iron(Ⅱ) complexes, whereas the well-resolved diamagnetic NMR spectra of 5 in combination with its 57Fe Mössbauer spectrum data (δ=0.05 mm/s, |ΔEQ|=0.40 mm/s) revealed its low-spin iron(Ⅱ) nature. The molecular structures of 3~5 have been characterized by single-crystal X-ray diffraction studies. The dianionic bis(amido)-arsorane ligands in 3 and 5 chelate to the metal centers in a fac-fashion with the Fe-As distances being 0.2562(3) and 0.2293(1) nm, respectively. The dianionic bis(amido)-iminoarsorane ligand in 4 binds to the iron(Ⅱ) center in a fac-fashion. The Fe-As distance (0.285 nm) observed in 4 is longer than the sum of the covalent radii of Fe and As, indicating the absence of strong Fe-As interaction in the iminoarsorane-iron(Ⅱ) complex. Its As-N distance of 0.1752(3) nm is found comparable to those of the As-N bonds in the reported iminoarsoranes and bis(arsoranylidene) ammonium compounds.
2018, 38(7): 1663-1672
doi: 10.6023/cjoc201712014
Abstract:
For HSbF6/EtOH system, diazo γ-pyrones were cleanly obtained starting from 2-diazo-3, 5-dioxo-6-ynoates/ynones/ynamide at 80℃, whereas diazo 3(2H)-furanones were predominantly generated in HOAc-Et3N-1, 2-dichloroethane system at 25℃. These diazo compounds can undergo an efficient Rh(Ⅱ)-catalyzed intermolecular cyclopropanation with alkene.
For HSbF6/EtOH system, diazo γ-pyrones were cleanly obtained starting from 2-diazo-3, 5-dioxo-6-ynoates/ynones/ynamide at 80℃, whereas diazo 3(2H)-furanones were predominantly generated in HOAc-Et3N-1, 2-dichloroethane system at 25℃. These diazo compounds can undergo an efficient Rh(Ⅱ)-catalyzed intermolecular cyclopropanation with alkene.
2018, 38(7): 1673-1679
doi: 10.6023/cjoc201712026
Abstract:
In this paper, a series of 6-substituted-pyrido[3, 2-e] [1, 2, 4]triazolo[4, 3-a]pyrazine derivatives have been synthesized. Their anticonvulsant activity and neurotoxicity in mice were evaluated by maximal electroshock (MES) and rotarod test, respectively. The structures were confirmed by 1H NMR, 13C NMR, MS and HRMS. The experimental results show that 6-phenoxypyrido[3, 2-e] [1, 2, 4]triazolo[4, 3-a]pyrazine (5g) was safer than the reference drug, carbamazepine, with ED50value of 93.9 mg·kg-1and protective index (PI) value of 24.3, which was a potential anti-epilepsy candidate compound.
In this paper, a series of 6-substituted-pyrido[3, 2-e] [1, 2, 4]triazolo[4, 3-a]pyrazine derivatives have been synthesized. Their anticonvulsant activity and neurotoxicity in mice were evaluated by maximal electroshock (MES) and rotarod test, respectively. The structures were confirmed by 1H NMR, 13C NMR, MS and HRMS. The experimental results show that 6-phenoxypyrido[3, 2-e] [1, 2, 4]triazolo[4, 3-a]pyrazine (5g) was safer than the reference drug, carbamazepine, with ED50value of 93.9 mg·kg-1and protective index (PI) value of 24.3, which was a potential anti-epilepsy candidate compound.
Synthesis and Fungicidal Activity of Novel Benzothiophene-Fused Pyrido[1, 2-a]pyrimidine Derivatives
2018, 38(7): 1680-1686
doi: 10.6023/cjoc201801016
Abstract:
A series of novel benzothieno[3', 2':2, 3]pyrido[4, 5-d]pyrido[1, 2-a]pyrimidines are prepared via Pictet-Spengler reaction of 2-(3-aminobenzothiophene-2-yl)-4H-pyrido[1, 2-a]pyrimidin-4-one using sulfamic acid as a catalyst, which in turn were obtained from the Thorpe-Ziegler isomerization of 2-(chloromethyl)-4H-pyrido[1, 2-a]pyrimidin-4-one with 2-mercapto-benzonitrile. The structures of the products were characterized by FT-IR, 1H NMR, 13C NMR spectra and elemental analysis. The fungicidal activities of the prepared compounds were also preliminarily evaluated. For example, 5b exhibited more than 96% inhibition rate to Botrytis cinerea and Gibberella zeae at 50 mg/L, 5f exhibited 98% inhibition rate to Sclerotonia sclerotiorum at 50 mg/L, and 5g, 5i exhibited more than 93% inhibition rate to Alternaria alternata at 50 mg/L.
A series of novel benzothieno[3', 2':2, 3]pyrido[4, 5-d]pyrido[1, 2-a]pyrimidines are prepared via Pictet-Spengler reaction of 2-(3-aminobenzothiophene-2-yl)-4H-pyrido[1, 2-a]pyrimidin-4-one using sulfamic acid as a catalyst, which in turn were obtained from the Thorpe-Ziegler isomerization of 2-(chloromethyl)-4H-pyrido[1, 2-a]pyrimidin-4-one with 2-mercapto-benzonitrile. The structures of the products were characterized by FT-IR, 1H NMR, 13C NMR spectra and elemental analysis. The fungicidal activities of the prepared compounds were also preliminarily evaluated. For example, 5b exhibited more than 96% inhibition rate to Botrytis cinerea and Gibberella zeae at 50 mg/L, 5f exhibited 98% inhibition rate to Sclerotonia sclerotiorum at 50 mg/L, and 5g, 5i exhibited more than 93% inhibition rate to Alternaria alternata at 50 mg/L.
2018, 38(7): 1687-1694
doi: 10.6023/cjoc201802004
Abstract:
Transition metal catalyzed asymmetric ring-opening reaction (ARO) of oxabenzonorbornadienes is a useful tool in the formation of carbon-carbon bond or carbon-heteroatom bond, which have attracted extensive study and received great achievements over the past decades. A series of efficient catalysts have been established and the high-level control of enantioselectivity for these reactions have been realized. A wide range of nucleophiles including carbon and heteroatom nucleophiles have been used in this reaction. Anhydride is a common acylation reagent and there has been no report about the ARO reaction of oxabenzonorbornadienes with anhydride, which can generate some useful chiral compounds. In this work, Rh-catalyzed ARO of oxabenzonorbornadienes with acetic anhydride and propionic anhydride have been developed. The developed protocol could result in ARO product in high yield (up to 94%) and excellent enantioselectivity (up to 95% ee).
Transition metal catalyzed asymmetric ring-opening reaction (ARO) of oxabenzonorbornadienes is a useful tool in the formation of carbon-carbon bond or carbon-heteroatom bond, which have attracted extensive study and received great achievements over the past decades. A series of efficient catalysts have been established and the high-level control of enantioselectivity for these reactions have been realized. A wide range of nucleophiles including carbon and heteroatom nucleophiles have been used in this reaction. Anhydride is a common acylation reagent and there has been no report about the ARO reaction of oxabenzonorbornadienes with anhydride, which can generate some useful chiral compounds. In this work, Rh-catalyzed ARO of oxabenzonorbornadienes with acetic anhydride and propionic anhydride have been developed. The developed protocol could result in ARO product in high yield (up to 94%) and excellent enantioselectivity (up to 95% ee).
2018, 38(7): 1695-1702
doi: 10.6023/cjoc201801029
Abstract:
2-Methyl-1-substituted-phenyl-2-propylamines are key intermediates for synthesizing the β2 adrenoceptor agonists. A series of 2-methyl-1-substituted-phenyl-2-propylamines have been synthesized starting from substituted benzyl chlorides. Isobutyronitrile was alkylated with benzyl chloride, and the resulting 2-methyl-1-aryl-2-butylcynide was hydrolyzed to give the corresponding acid. Curtius rearrangement of the acid and catalytic hydrolgenation of the resulting Cbz-protected amine afforded the title compound. The method is simple and safe to operate, the raw materials are readily available and the overall yields are satisfactory. This method is suitable for the synthesis of 2-methyl-2-(2-methylphenyl)-phenyl-2-propylamine and various kinds of derivatives.
2-Methyl-1-substituted-phenyl-2-propylamines are key intermediates for synthesizing the β2 adrenoceptor agonists. A series of 2-methyl-1-substituted-phenyl-2-propylamines have been synthesized starting from substituted benzyl chlorides. Isobutyronitrile was alkylated with benzyl chloride, and the resulting 2-methyl-1-aryl-2-butylcynide was hydrolyzed to give the corresponding acid. Curtius rearrangement of the acid and catalytic hydrolgenation of the resulting Cbz-protected amine afforded the title compound. The method is simple and safe to operate, the raw materials are readily available and the overall yields are satisfactory. This method is suitable for the synthesis of 2-methyl-2-(2-methylphenyl)-phenyl-2-propylamine and various kinds of derivatives.
2018, 38(7): 1703-1711
doi: 10.6023/cjoc201801031
Abstract:
A green and efficient catalytic system has been developed for the Cu-catalyzed Ullmann-type C-N coupling reactions in water. With CuI as catalyst, N-(2-hydroxyethyl)-β-D-glucopyranosylamine as ligand, aryl iodides and aryl bromides bearing various electron-withdrawing and electron-donating groups could be coupled with N-nucleophiles in water with good yields (61%~96%). The catalytic system was expanded successfully to the reaction of indoles with 4-iodoanisole in water.
A green and efficient catalytic system has been developed for the Cu-catalyzed Ullmann-type C-N coupling reactions in water. With CuI as catalyst, N-(2-hydroxyethyl)-β-D-glucopyranosylamine as ligand, aryl iodides and aryl bromides bearing various electron-withdrawing and electron-donating groups could be coupled with N-nucleophiles in water with good yields (61%~96%). The catalytic system was expanded successfully to the reaction of indoles with 4-iodoanisole in water.
2018, 38(7): 1718-1724
doi: 10.6023/cjoc201712037
Abstract:
A host-guest system was successfully constructed from dimethoxypillar[5]arene (DMP5) and six guest molecules benzoazolidazole (G2), benzimidazole (G3) and benzothiazole (G1, G4, G5 and G6) via host-guest interactions and characterized by various techniques, including HRMS and 1H NMR spectra. The result shows that heterocyclic compound was threaded into the cavity of pillar[5]arene to obtain host-guest system between DMpillar[5]arene and benzazole, forming inclusion complexes. Interestingly, the corresponding guest containing benzazole formed a stable host-guest complex with the same host. Moreover, the addition of guest compounds led to the effective reinforcement of the fluorescence intensity compared with the original guest species and the host (DMP5) that giving an additional support for the host-guest interaction based supramolecular assembly nature of the present system.
A host-guest system was successfully constructed from dimethoxypillar[5]arene (DMP5) and six guest molecules benzoazolidazole (G2), benzimidazole (G3) and benzothiazole (G1, G4, G5 and G6) via host-guest interactions and characterized by various techniques, including HRMS and 1H NMR spectra. The result shows that heterocyclic compound was threaded into the cavity of pillar[5]arene to obtain host-guest system between DMpillar[5]arene and benzazole, forming inclusion complexes. Interestingly, the corresponding guest containing benzazole formed a stable host-guest complex with the same host. Moreover, the addition of guest compounds led to the effective reinforcement of the fluorescence intensity compared with the original guest species and the host (DMP5) that giving an additional support for the host-guest interaction based supramolecular assembly nature of the present system.
2018, 38(7): 1725-1732
doi: 10.6023/cjoc201801021
Abstract:
An one-pot reaction of various isatin compounds or α-keto esters and ethyl 2-(bromomethyl)acrylate promoted by tin powder has been investigated, affording the corresponding isatin-derived spirocyclic α-methylene-γ-butyrolactones or γ, γ-disubstituted α-methylene-γ-butyrolactones in high yields. The method uses the combination of tin powder and ethyl 2-(bromomethyl)acrylate to replace the corresponding toxic stannanes and allows the operation much easier.
An one-pot reaction of various isatin compounds or α-keto esters and ethyl 2-(bromomethyl)acrylate promoted by tin powder has been investigated, affording the corresponding isatin-derived spirocyclic α-methylene-γ-butyrolactones or γ, γ-disubstituted α-methylene-γ-butyrolactones in high yields. The method uses the combination of tin powder and ethyl 2-(bromomethyl)acrylate to replace the corresponding toxic stannanes and allows the operation much easier.
2018, 38(7): 1733-1739
doi: 10.6023/cjoc201802009
Abstract:
A series of water-soluble sulfonated porphyrins have been synthesized and characterized by 1H NMR, IR, UV-Vis, fluorescence and MS. The fluorescence quantum yield and lifetime of the series of porphyrins have been obtained. These porphyrins have been used as photocatalysts for the oxidation of 2, 3-dihydroxynaphthalene. The main product has been proved to be 1, 2-benzenedicarboxylic acid with the highest conversion rate of 91%. The effects of electron caused by different substituent groups and steric structure on sulfonated porphyrins photocatalytic activities have been investigated. It has been proved that substituent groups have electronic effects on the photocatalytic activities. The chosen of oxygen resource, the kinetics of the oxidation and the photocatalytic mechanism of sulfonated porphyrins have been investigated.
A series of water-soluble sulfonated porphyrins have been synthesized and characterized by 1H NMR, IR, UV-Vis, fluorescence and MS. The fluorescence quantum yield and lifetime of the series of porphyrins have been obtained. These porphyrins have been used as photocatalysts for the oxidation of 2, 3-dihydroxynaphthalene. The main product has been proved to be 1, 2-benzenedicarboxylic acid with the highest conversion rate of 91%. The effects of electron caused by different substituent groups and steric structure on sulfonated porphyrins photocatalytic activities have been investigated. It has been proved that substituent groups have electronic effects on the photocatalytic activities. The chosen of oxygen resource, the kinetics of the oxidation and the photocatalytic mechanism of sulfonated porphyrins have been investigated.
2018, 38(7): 1749-1754
doi: 10.6023/cjoc201802006
Abstract:
A convenient and excellent yield procedure for the preparation of benzylidenemalononitrile by addition-elimination reaction of imine with malonitrile in the presence of immobilized H3PW12O40 as heterogeneous catalyst in water is described, and a variety of the corresponding products were obtained in high yield (up to 99%). The approach was characterized by simple operation, environment friendly, excellent yields and the catalyst was found to exhibit better recyclability. It provides a new method for the carbon-carbon bond formation in organic synthesis.
A convenient and excellent yield procedure for the preparation of benzylidenemalononitrile by addition-elimination reaction of imine with malonitrile in the presence of immobilized H3PW12O40 as heterogeneous catalyst in water is described, and a variety of the corresponding products were obtained in high yield (up to 99%). The approach was characterized by simple operation, environment friendly, excellent yields and the catalyst was found to exhibit better recyclability. It provides a new method for the carbon-carbon bond formation in organic synthesis.
2018, 38(7): 1755-1762
doi: 10.6023/cjoc201802015
Abstract:
In order to find novel pyrazole oximes with good bioactivities, a series of novel pyrazole oxime derivatives containing substituted oxadiazole moiety were designed and synthesized according to the method of active substructure combination. Their structures were confirmed by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay data indicated that some title compounds showed good insecticidal activities. At the concentration of 500 μg/mL, 9 compounds possessed insecticidal activity against Oriental armyworm with 80%~100%. When the concentration was lowered to 100 μg/mL, 3 compounds still displayed significant insecticidal activity against Oriental armyworm with 70%, 60% and 70%. Additionally, one compound had 60% insecticidal activity against Aphis medicaginis at 500 μg/mL.
In order to find novel pyrazole oximes with good bioactivities, a series of novel pyrazole oxime derivatives containing substituted oxadiazole moiety were designed and synthesized according to the method of active substructure combination. Their structures were confirmed by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay data indicated that some title compounds showed good insecticidal activities. At the concentration of 500 μg/mL, 9 compounds possessed insecticidal activity against Oriental armyworm with 80%~100%. When the concentration was lowered to 100 μg/mL, 3 compounds still displayed significant insecticidal activity against Oriental armyworm with 70%, 60% and 70%. Additionally, one compound had 60% insecticidal activity against Aphis medicaginis at 500 μg/mL.
2018, 38(7): 1763-1771
doi: 10.6023/cjoc201712027
Abstract:
Twenty one new heterocyclic chalcone derivatives were synthesized by the Claisen-Schmidt condensation and ammonolysis of acyl chloride using heterocyclic aldehyde and amino substituted acetophenone as well as acyl chloride as raw materials. The laboratorial bioassay of the insecticidal activity of the synthesized compounds was performed using Aphis craccivora and Pieris rapae as targets. The results showed that most of them had significant insecticidal activity against the two pests. Among them, the median lethal concentration (LC50) of compound 2l was 1.6 μg/mL against Aphis craccivora, whose insecticidal efficacy was superior to imidacloprid with LC50 of 1.8 μg/mL. The insecticidal efficacy of 1b, 1f, 2j and 2n was also close to imidacloprid against Aphis craccivora. The LC50 values of compounds 1f and 2m against Aphis craccivora and Pieris rapae were 6.6 μg/mL and 8.5 μg/mL, respectively and their insecticidal activity exceeded β-cypermethrin, whose LC50 was 9.2 μg/mL.
Twenty one new heterocyclic chalcone derivatives were synthesized by the Claisen-Schmidt condensation and ammonolysis of acyl chloride using heterocyclic aldehyde and amino substituted acetophenone as well as acyl chloride as raw materials. The laboratorial bioassay of the insecticidal activity of the synthesized compounds was performed using Aphis craccivora and Pieris rapae as targets. The results showed that most of them had significant insecticidal activity against the two pests. Among them, the median lethal concentration (LC50) of compound 2l was 1.6 μg/mL against Aphis craccivora, whose insecticidal efficacy was superior to imidacloprid with LC50 of 1.8 μg/mL. The insecticidal efficacy of 1b, 1f, 2j and 2n was also close to imidacloprid against Aphis craccivora. The LC50 values of compounds 1f and 2m against Aphis craccivora and Pieris rapae were 6.6 μg/mL and 8.5 μg/mL, respectively and their insecticidal activity exceeded β-cypermethrin, whose LC50 was 9.2 μg/mL.
2018, 38(7): 1772-1778
doi: 10.6023/cjoc201802026
Abstract:
In search of novel cyanoacrylates with potent bioactivity, a series of new cyanoacrylate derivatives containing substituted oxazole moiety were designed and synthesized through the strategy of active substructure combination. They were structurally characterized by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay data showed that most title compounds possessed good herbicidal activity at the dosage of 1500 g/ha, 9 compounds exhibited herbicidal activity against Brassica juncea with 80%~100%, 12 compounds had herbicidal activity against Chenopodium serotinum L. with 80%~100%, two compounds both displayed 70% herbicidal activity against Alopecurus aequalis Sobol, and one compound showed 100%, 70%, and 60% herbicidal activity against Rumex acetosa L., Polypogon fugax Nees ex Steud and Poa acroleuca Steud, respectively. Additionally, the inhibitory rates of one compound against Brassica juncea and Rumex acetosa L.were both 30% at 37.5 g/ha.
In search of novel cyanoacrylates with potent bioactivity, a series of new cyanoacrylate derivatives containing substituted oxazole moiety were designed and synthesized through the strategy of active substructure combination. They were structurally characterized by 1H NMR, 13C NMR and elemental analysis. Preliminary bioassay data showed that most title compounds possessed good herbicidal activity at the dosage of 1500 g/ha, 9 compounds exhibited herbicidal activity against Brassica juncea with 80%~100%, 12 compounds had herbicidal activity against Chenopodium serotinum L. with 80%~100%, two compounds both displayed 70% herbicidal activity against Alopecurus aequalis Sobol, and one compound showed 100%, 70%, and 60% herbicidal activity against Rumex acetosa L., Polypogon fugax Nees ex Steud and Poa acroleuca Steud, respectively. Additionally, the inhibitory rates of one compound against Brassica juncea and Rumex acetosa L.were both 30% at 37.5 g/ha.
2018, 38(7): 1786-1791
doi: 10.6023/cjoc201802014
Abstract:
A novel fluorescent probe L with long wavelength emission and large Stokes shift was designed and synthesized based on 1, 4-diethyl-7-hydroxytetrahydroquinoxaline-6-carboxaldehyde. The color of L was changed from yellow to pink and colorless upon addition of Cu2+ and Co2+ respectively in dimethylsulfoxide (DMSO), which illustrated that probe L could recognize Cu2+ and Co2+ by naked eyes. The complex L-Cu2+ could recognize H2S with fluorescence "OFF-ON" in DMSO/H2O (V:V=7:3, HEPES, 1×10-2 mol/L, pH=7.4). The test strip assay showed that the L-Cu2+ pretreated test strip showed obvious color changes toward different concentrations of H2S, which indicated that H2S could be rapidly detected by naked eyes and fluorescent double channel. In addition, the molecular target of compound L can be searched by utilizing the reverse docking method in Discovery Studio (DS) software. Then, docking analysis was performed using CDOCKER module of DS, and it was found that molecule L has a good combination to 2x0v protein (P53_human). Therefore, it is expected to be applied in the medicine field.
A novel fluorescent probe L with long wavelength emission and large Stokes shift was designed and synthesized based on 1, 4-diethyl-7-hydroxytetrahydroquinoxaline-6-carboxaldehyde. The color of L was changed from yellow to pink and colorless upon addition of Cu2+ and Co2+ respectively in dimethylsulfoxide (DMSO), which illustrated that probe L could recognize Cu2+ and Co2+ by naked eyes. The complex L-Cu2+ could recognize H2S with fluorescence "OFF-ON" in DMSO/H2O (V:V=7:3, HEPES, 1×10-2 mol/L, pH=7.4). The test strip assay showed that the L-Cu2+ pretreated test strip showed obvious color changes toward different concentrations of H2S, which indicated that H2S could be rapidly detected by naked eyes and fluorescent double channel. In addition, the molecular target of compound L can be searched by utilizing the reverse docking method in Discovery Studio (DS) software. Then, docking analysis was performed using CDOCKER module of DS, and it was found that molecule L has a good combination to 2x0v protein (P53_human). Therefore, it is expected to be applied in the medicine field.
2018, 38(7): 1800-1805
doi: 10.6023/cjoc201711002
Abstract:
A novel sensor molecule 2-hydroxyl-1-naldehyde-N-(4-aminophenyl)-1, 8-naphthalimide (H1) based on functionalized naphthalimide Schiff Base derivative was synthesized. H1 was characterized by 1H NMR, 13C NMR and HRMS. Furthermore, its fluorescence properties were studied in dimethyl sulfoxide (DMSO)/H2O (V:V=7:3) solutions. Its maximum emission wavelength was 496 nm. The solution of H1 has yellow-green fluorescence under the UV lamp (365 nm). H1 showed fluorescence-colorimetric dual channel identification ability for Fe3+. With the addition of various metal ions into the H1 solution, only Fe3+ caused the fluorescence of the H1 quenching and the color disappeared. Other cations such as Ag+, Ca2+, Ba2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cu2+, Mg2+ and Hg2+ could not induce similar response. The results of anti-disturbance experiment demonstrated that other cations can not interfere in the detection of Fe3+. H1 has good sensitivity for Fe3+, the fluorescence and UV-Vis detection limits of the H1 for Fe3+ are 3.04×10-8 and 2.71×10-6 mol·L-1, respectively. Finally, the test strips based on the H1 were prepared, which could conveniently and efficiently detect Fe3+ in water.
A novel sensor molecule 2-hydroxyl-1-naldehyde-N-(4-aminophenyl)-1, 8-naphthalimide (H1) based on functionalized naphthalimide Schiff Base derivative was synthesized. H1 was characterized by 1H NMR, 13C NMR and HRMS. Furthermore, its fluorescence properties were studied in dimethyl sulfoxide (DMSO)/H2O (V:V=7:3) solutions. Its maximum emission wavelength was 496 nm. The solution of H1 has yellow-green fluorescence under the UV lamp (365 nm). H1 showed fluorescence-colorimetric dual channel identification ability for Fe3+. With the addition of various metal ions into the H1 solution, only Fe3+ caused the fluorescence of the H1 quenching and the color disappeared. Other cations such as Ag+, Ca2+, Ba2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cu2+, Mg2+ and Hg2+ could not induce similar response. The results of anti-disturbance experiment demonstrated that other cations can not interfere in the detection of Fe3+. H1 has good sensitivity for Fe3+, the fluorescence and UV-Vis detection limits of the H1 for Fe3+ are 3.04×10-8 and 2.71×10-6 mol·L-1, respectively. Finally, the test strips based on the H1 were prepared, which could conveniently and efficiently detect Fe3+ in water.
2018, 38(7): 1712-1717
doi: 10.6023/cjoc201801036
Abstract:
Selectfluor, 1-chloromethyl-4-fluoro-1, 4-diazoniabicyclo-[2.2.2] octane bis(tetrafluoroborate), is among the most popular fluorinating reagents owning to its commercially availability and non-hygroscopic property. The discovery and understanding of new reactivities of selectfluor are thus important for reaction design and optimization when this popular reagent is employed. It has been found that selectfluor could selectively remove Boc group from doubly protected amines in acetonitrile. This deprotection could be of interest when compared to other reported methods, not only because selectfluor is a solid and easy-to-handle, but also because the reaction is mild, operationally simple and chemoselective. The potential usefulness of this method is demonstrated by the deprotection of a series of protected amino acids and a one-step synthesis of pharmaceutically important purine derivative. The NMR experiments conducted in CD3CN explain why stoichiometric amount of selectfluor is needed for a successful reaction.
Selectfluor, 1-chloromethyl-4-fluoro-1, 4-diazoniabicyclo-[2.2.2] octane bis(tetrafluoroborate), is among the most popular fluorinating reagents owning to its commercially availability and non-hygroscopic property. The discovery and understanding of new reactivities of selectfluor are thus important for reaction design and optimization when this popular reagent is employed. It has been found that selectfluor could selectively remove Boc group from doubly protected amines in acetonitrile. This deprotection could be of interest when compared to other reported methods, not only because selectfluor is a solid and easy-to-handle, but also because the reaction is mild, operationally simple and chemoselective. The potential usefulness of this method is demonstrated by the deprotection of a series of protected amino acids and a one-step synthesis of pharmaceutically important purine derivative. The NMR experiments conducted in CD3CN explain why stoichiometric amount of selectfluor is needed for a successful reaction.
2018, 38(7): 1740-1748
doi: 10.6023/cjoc201801049
Abstract:
A mild, general and efficient method for the direct synthesis of diverse amides from commercially available carboxylic acids and isothiocyanates has been developed. The strategy does not require stoichiometric amounts of coupling reagents or metal catalysts, and is especially for sterically hindered and electron-deficient secondary amides, which are otherwise challenging to synthesize.
A mild, general and efficient method for the direct synthesis of diverse amides from commercially available carboxylic acids and isothiocyanates has been developed. The strategy does not require stoichiometric amounts of coupling reagents or metal catalysts, and is especially for sterically hindered and electron-deficient secondary amides, which are otherwise challenging to synthesize.
2018, 38(7): 1779-1785
doi: 10.6023/cjoc201801044
Abstract:
Magnetic resonance imaging (MRI) is widely used in diagnostic medicine and soft tissue imaging. Contrast agents (CAs) can improve the specificity of MRI enhancement. Herein, the design, synthesis and relaxivity of two novel binuclear nonionic Gd-based DOTA-hydrazide derived MRI contrast agents, (Gd-DOTAH)2-DYMB and (Gd-DOTAH)2-DYMBP are reported. They have improved longitudinal relaxivity values of 11.4 and 11.7 L·mmol-1·s-1 per molecule or 5.7 and 5.9 L·mmol-1·Gd-1·s-1 at 0.5 T, respectively, which are higher than that of the mononuclear clinical macrocyclic agent Gd-DOTA. And in vitro MRI studies suggest the potential of these two agents as MRI contrast agents in improving the diagnostic sensitivity and accuracy.
Magnetic resonance imaging (MRI) is widely used in diagnostic medicine and soft tissue imaging. Contrast agents (CAs) can improve the specificity of MRI enhancement. Herein, the design, synthesis and relaxivity of two novel binuclear nonionic Gd-based DOTA-hydrazide derived MRI contrast agents, (Gd-DOTAH)2-DYMB and (Gd-DOTAH)2-DYMBP are reported. They have improved longitudinal relaxivity values of 11.4 and 11.7 L·mmol-1·s-1 per molecule or 5.7 and 5.9 L·mmol-1·Gd-1·s-1 at 0.5 T, respectively, which are higher than that of the mononuclear clinical macrocyclic agent Gd-DOTA. And in vitro MRI studies suggest the potential of these two agents as MRI contrast agents in improving the diagnostic sensitivity and accuracy.
2018, 38(7): 1792-1799
doi: 10.6023/cjoc201712004
Abstract:
It is well-known that cyanide anion (CN-) is a hypertoxic anion, which can cause adverse effects in both environment and living beings. Thus, it is highly desirable to develop strategies for detecting cyanide, especially in aqueous medium and food. However, due to the short half-life of free cyanide, long analysis time and interference from other competitive anions are general challenges for accurate monitoring of cyanide. Taking advantage of the special nucleophilicity of cyanide, a new colorimetric and fluorescent sensor (Q1-2) was synthesized based on naphtho[2, 1-b]furan-2-carbonyl chloride and 2-aminobenzimidazole which designed by tuning the intramolecular hydrogen bonding to affect the π-conjugated efficiency. Upon the addition of cyanide anion, the probe displayed a red-shift in absorption spectra and the fluorescence decreased immediately with the detection limit of 8.0769×10-7 and 1.0510×10-9 mol/L, respectively. Other anions gave nearly no interference. Furthermore, Q1-2 was successfully applied to the naked eye identification for cyanide in the visible light and under the UV lamp in food samples and silica gel plates.
It is well-known that cyanide anion (CN-) is a hypertoxic anion, which can cause adverse effects in both environment and living beings. Thus, it is highly desirable to develop strategies for detecting cyanide, especially in aqueous medium and food. However, due to the short half-life of free cyanide, long analysis time and interference from other competitive anions are general challenges for accurate monitoring of cyanide. Taking advantage of the special nucleophilicity of cyanide, a new colorimetric and fluorescent sensor (Q1-2) was synthesized based on naphtho[2, 1-b]furan-2-carbonyl chloride and 2-aminobenzimidazole which designed by tuning the intramolecular hydrogen bonding to affect the π-conjugated efficiency. Upon the addition of cyanide anion, the probe displayed a red-shift in absorption spectra and the fluorescence decreased immediately with the detection limit of 8.0769×10-7 and 1.0510×10-9 mol/L, respectively. Other anions gave nearly no interference. Furthermore, Q1-2 was successfully applied to the naked eye identification for cyanide in the visible light and under the UV lamp in food samples and silica gel plates.
2018, 38(7): 1806-1810
doi: 10.6023/cjoc201711049
Abstract:
Fluoride ion is an anion with the high electronegativity and the smallest radius. It has important application in all aspects of daily life. In this paper, based on the cleavage of Si-O bond induced by fluoride ions, a novel derivative of perylene B which contains four silicon oxygen bond was designed and synthesized, and this fluorescent chemosensor could recognize F- with good selectivity and high sensitivity. The probe molecule had a fast response time for F- and the sensing procedure could be completed in about 1 min, and the detection limit of F- of the probe molecule B reached 3.5×10-8 mol·L-1.
Fluoride ion is an anion with the high electronegativity and the smallest radius. It has important application in all aspects of daily life. In this paper, based on the cleavage of Si-O bond induced by fluoride ions, a novel derivative of perylene B which contains four silicon oxygen bond was designed and synthesized, and this fluorescent chemosensor could recognize F- with good selectivity and high sensitivity. The probe molecule had a fast response time for F- and the sensing procedure could be completed in about 1 min, and the detection limit of F- of the probe molecule B reached 3.5×10-8 mol·L-1.
2018, 38(7): 1811-1816
doi: 10.6023/cjoc201710003
Abstract:
A novel one-pot chemo-enzymatic method was developed for the preparation of chiral α-halogenated aryl alcohols from cheap aryl ketones. Firstly, the α-halogenated aryl ketones were obtained via halogenation of aryl ketones catalyzed by p-toluenesulfonic acid. Then, α-halogenated aryl ketones was asymmetric reduced to chiral α-halogenated aryl alcohols by adding cell suspension of Rhodotorula sp. AS2.2241 with carbonyl reductase activity into the reaction system without isolating intermediate products. The best reaction condition was optimized for each step and the coupling condition of chemical and biological reaction was studied in detail. It was found that the concentration of organic solvent and the pH value are key factors that affect the enzyme activity of biocatalytic reaction. Under optimized reaction and coupling conditions, four kinds of chiral α-halogenated aryl alcohols were obtained with high yield and high optical purity (yield > 95%, ee > 99%).
A novel one-pot chemo-enzymatic method was developed for the preparation of chiral α-halogenated aryl alcohols from cheap aryl ketones. Firstly, the α-halogenated aryl ketones were obtained via halogenation of aryl ketones catalyzed by p-toluenesulfonic acid. Then, α-halogenated aryl ketones was asymmetric reduced to chiral α-halogenated aryl alcohols by adding cell suspension of Rhodotorula sp. AS2.2241 with carbonyl reductase activity into the reaction system without isolating intermediate products. The best reaction condition was optimized for each step and the coupling condition of chemical and biological reaction was studied in detail. It was found that the concentration of organic solvent and the pH value are key factors that affect the enzyme activity of biocatalytic reaction. Under optimized reaction and coupling conditions, four kinds of chiral α-halogenated aryl alcohols were obtained with high yield and high optical purity (yield > 95%, ee > 99%).
2018, 38(7): 1817-1822
doi: 10.6023/cjoc201801030
Abstract:
An economic and environmental synthestic method for 3-chloroindenes from o-(alkynyl)styrenes through tandem reactions including choropalladation/Heck cross coupling in Pd/O2 system was reported. Taking green dioxygen as sole oxidant and LiCl as chlorine source, 13 functionalized 3-chloroindenes could be synthesized in moderate to high yield without the addition of CuCl2
An economic and environmental synthestic method for 3-chloroindenes from o-(alkynyl)styrenes through tandem reactions including choropalladation/Heck cross coupling in Pd/O2 system was reported. Taking green dioxygen as sole oxidant and LiCl as chlorine source, 13 functionalized 3-chloroindenes could be synthesized in moderate to high yield without the addition of CuCl2
2018, 38(7): 1823-1828
doi: 10.6023/cjoc201801025
Abstract:
Under neutral reaction conditions, sodium triflate promotes the radical reaction of potassium persulfate with water to yield a proton which induces Schmidt rearrangement of alkenyl azides. A variety of substituted acetanilide compounds were synthesized in one step. To obtain the optimal reaction conditions, an arrange of reaction parameters such as radical initiator, solvent, temperature, and reaction time have been screened. This reaction features an easy accessibility of starting materials, simple operation, broad substrate scope and so on. We finally proposed the plausible mechanism based on the mechanistic studies and previous literature.
Under neutral reaction conditions, sodium triflate promotes the radical reaction of potassium persulfate with water to yield a proton which induces Schmidt rearrangement of alkenyl azides. A variety of substituted acetanilide compounds were synthesized in one step. To obtain the optimal reaction conditions, an arrange of reaction parameters such as radical initiator, solvent, temperature, and reaction time have been screened. This reaction features an easy accessibility of starting materials, simple operation, broad substrate scope and so on. We finally proposed the plausible mechanism based on the mechanistic studies and previous literature.
2018, 38(7): 1833-1836
doi: 10.6023/cjoc201801042
Abstract:
A new indole alkaloid, nauclofficine (1), together with three known alkaloids, naucleamide A (2), naucleamide D (3) and latifoliamide A (4), were isolated from the stems and leaves of Nauclea officinalis. Their structures were established on the basis of extensive spectral analyses. All known compounds were isolated from N. officinalis for the first time. The cytotoxicities of compounds 1~4 were evaluated against five cancer cell lines (HL-60, A549, SMMC-7721, MCF-7 and SW480). Research results showed that compounds 1~4 exhibited significant inhibitory effects with IC50 values comparable to those of cisplatin.
A new indole alkaloid, nauclofficine (1), together with three known alkaloids, naucleamide A (2), naucleamide D (3) and latifoliamide A (4), were isolated from the stems and leaves of Nauclea officinalis. Their structures were established on the basis of extensive spectral analyses. All known compounds were isolated from N. officinalis for the first time. The cytotoxicities of compounds 1~4 were evaluated against five cancer cell lines (HL-60, A549, SMMC-7721, MCF-7 and SW480). Research results showed that compounds 1~4 exhibited significant inhibitory effects with IC50 values comparable to those of cisplatin.
2018, 38(7): 1837-1841
doi: 10.6023/cjoc201801047
Abstract:
A series of 2-aminothiophene derivatives were synthesized by the Gewald reaction between α-active methylene nitrilthes and 2, 5-dihydroxy-1, 4-dithiane using amano lipase M from Mucor javanicus as biocatalyst. The method has the advantages of mild reaction conditions, biodegradability of catalyst and wide range of substrates compared with traditional catalysts.
A series of 2-aminothiophene derivatives were synthesized by the Gewald reaction between α-active methylene nitrilthes and 2, 5-dihydroxy-1, 4-dithiane using amano lipase M from Mucor javanicus as biocatalyst. The method has the advantages of mild reaction conditions, biodegradability of catalyst and wide range of substrates compared with traditional catalysts.
2018, 38(7): 1842-1848
doi: 10.6023/cjoc201801019
Abstract:
Twenty-two novel substituted 2-(pyridin-3-yl)-2-benzoyloxy acetamides were synthesized via Passerini three-component reaction involving 3-pyridinecarboxaldehyde, substituted benzoic acid, and tert-butyl isocyanide (or 1, 1, 3, 3-tetramethylbutyl isocyanide) in water, and characterized by IR, 1H NMR, 13C NMR and HRMS. This method provides some advantages such as mild conditions, short reaction time, facile operation and high yield. Moreover, the target compounds were evaluated for their in vitro antifungal activities against two plant pathogens by the mycelium growth rate method, and the results indicated that at the dosage of 100 μg/mL, eight compounds showed moderate activities against B. cinerea with inhibition rates of 83%~89%, and seventeen compounds exhibited strong activities against S. sclerotiorum with inhibition rates of 90%~100%.
Twenty-two novel substituted 2-(pyridin-3-yl)-2-benzoyloxy acetamides were synthesized via Passerini three-component reaction involving 3-pyridinecarboxaldehyde, substituted benzoic acid, and tert-butyl isocyanide (or 1, 1, 3, 3-tetramethylbutyl isocyanide) in water, and characterized by IR, 1H NMR, 13C NMR and HRMS. This method provides some advantages such as mild conditions, short reaction time, facile operation and high yield. Moreover, the target compounds were evaluated for their in vitro antifungal activities against two plant pathogens by the mycelium growth rate method, and the results indicated that at the dosage of 100 μg/mL, eight compounds showed moderate activities against B. cinerea with inhibition rates of 83%~89%, and seventeen compounds exhibited strong activities against S. sclerotiorum with inhibition rates of 90%~100%.
2018, 38(7): 1829-1832
doi: 10.6023/cjoc201801027
Abstract:
Seven sesquterpenoids were obtained from the Chinese traditional medicine, Fructus carotae, and their structures were identified as 7-ethoxy-4(15)-oppositen-1β-ol (1), 11-acetoxy-8β-angeloyloxy-15-methoxy-4α, 5α-epoxyarbutane-3-one (2), 11-acetoxy-8β-propionyl-4-guaien-3-one (3), 1-oxo-5α, 7αH-eudesma-3-en-15-al (4), 1β-hydroxy-4(15), 7-eudesmadiene (5), 1β-hydroxy-4(15), 5E, 10(14)-germacratriene (6) and 1β-hydroxy-4(15), 5-eudesmadiene (7). Compounds 1 and 2 were new sesquterpenoid compounds, and their structures were determined by the analysis of HR-ESIMS, 1D NMR and 2D NMR.
Seven sesquterpenoids were obtained from the Chinese traditional medicine, Fructus carotae, and their structures were identified as 7-ethoxy-4(15)-oppositen-1β-ol (1), 11-acetoxy-8β-angeloyloxy-15-methoxy-4α, 5α-epoxyarbutane-3-one (2), 11-acetoxy-8β-propionyl-4-guaien-3-one (3), 1-oxo-5α, 7αH-eudesma-3-en-15-al (4), 1β-hydroxy-4(15), 7-eudesmadiene (5), 1β-hydroxy-4(15), 5E, 10(14)-germacratriene (6) and 1β-hydroxy-4(15), 5-eudesmadiene (7). Compounds 1 and 2 were new sesquterpenoid compounds, and their structures were determined by the analysis of HR-ESIMS, 1D NMR and 2D NMR.
2018, 38(7): 1849-1854
doi: 10.6023/cjoc201711041
Abstract:
An efficient protocol for conversion of azobenzenes into their ortho-nitro derivatives via palladium-catalyzed C-H bond activation has been developed. Commercially available and less expensive Co(NO3)2·6H2O was used as the nitrification reagent. Various o-nitroazobenzenes were obtained in excellent yields.
An efficient protocol for conversion of azobenzenes into their ortho-nitro derivatives via palladium-catalyzed C-H bond activation has been developed. Commercially available and less expensive Co(NO3)2·6H2O was used as the nitrification reagent. Various o-nitroazobenzenes were obtained in excellent yields.
