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2016 Volume 36 Issue 6
2016, 36(6): 1151-1162
doi: 10.6023/cjoc201603042
Abstract:
The difunctionalization of unsaturated carbon-carbon bonds is a powerful strategy for the synthesis of various organic compounds. Recently, the remarkable progress has been made in difunctionalization of unsaturated carbon-carbon bonds with dioxygen and radicals. The present protocol, which utilizes dioxygen as oxygen source, provides a green and atom economy approach to alcohols or ketones. This review will summarize the recent development in this area on the basis of different types of radicals.
The difunctionalization of unsaturated carbon-carbon bonds is a powerful strategy for the synthesis of various organic compounds. Recently, the remarkable progress has been made in difunctionalization of unsaturated carbon-carbon bonds with dioxygen and radicals. The present protocol, which utilizes dioxygen as oxygen source, provides a green and atom economy approach to alcohols or ketones. This review will summarize the recent development in this area on the basis of different types of radicals.
2016, 36(6): 1163-1183
doi: 10.6023/cjoc201512010
Abstract:
Organic compounds that contain nitrogen are very important intermediates in pharmaceutical and chemical industry. Hydroamination is the reaction that can form C—N bond with high atom economy. The research progress in non-noble metals catalyzed hydroamination of alkenes and alkynes from the perspective of reaction mechanism is categorized and summarized.
Organic compounds that contain nitrogen are very important intermediates in pharmaceutical and chemical industry. Hydroamination is the reaction that can form C—N bond with high atom economy. The research progress in non-noble metals catalyzed hydroamination of alkenes and alkynes from the perspective of reaction mechanism is categorized and summarized.
2016, 36(6): 1184-1196
doi: 10.6023/cjoc201512017
Abstract:
Being an active class of electrophiles, the desulfitative cross-couplings of sulfonyl chlorides has emerged as a hot issue nowadays. Under suitable temperature and transitional metal catalysis, sulfonyl chlorides efficiently cross-coupled with a wide range of nucleophiles which were potential in several important organic synthesis. The transitional metal catalyzed desulfitative coupling reactions of sulfonyl chlorides are briefly reviewed and are compared with their corresponding sulfonylation reaction in order to find the key factors that determine desulfonation and further providing reliable proposal for future researches.
Being an active class of electrophiles, the desulfitative cross-couplings of sulfonyl chlorides has emerged as a hot issue nowadays. Under suitable temperature and transitional metal catalysis, sulfonyl chlorides efficiently cross-coupled with a wide range of nucleophiles which were potential in several important organic synthesis. The transitional metal catalyzed desulfitative coupling reactions of sulfonyl chlorides are briefly reviewed and are compared with their corresponding sulfonylation reaction in order to find the key factors that determine desulfonation and further providing reliable proposal for future researches.
2016, 36(6): 1197-1207
doi: 10.6023/cjoc201512024
Abstract:
Fused aza-polycyclic structures play an important role in the synthesis of energetic compounds and the presence of NNO2 groups renders them a rich source of energy. Currently, fused aza-polynitrocyclic compounds have gained considerable prominence as novel energetic compounds. This review focuses on the synthesis of various ring skeletons of the aza-bicyclic, aza-polycyclic and aza-propellane-derivatized energetic compounds as well as the studies of N-nitration, physicochemistry and detonation properties. The synthesis of pentaaza[3.3.3]propellane and hexaaza[3.3.3]propellane is highlighted and N-nitration explorations of these high-strained unstable skeletons are discussed in details.
Fused aza-polycyclic structures play an important role in the synthesis of energetic compounds and the presence of NNO2 groups renders them a rich source of energy. Currently, fused aza-polynitrocyclic compounds have gained considerable prominence as novel energetic compounds. This review focuses on the synthesis of various ring skeletons of the aza-bicyclic, aza-polycyclic and aza-propellane-derivatized energetic compounds as well as the studies of N-nitration, physicochemistry and detonation properties. The synthesis of pentaaza[3.3.3]propellane and hexaaza[3.3.3]propellane is highlighted and N-nitration explorations of these high-strained unstable skeletons are discussed in details.
2016, 36(6): 1208-1217
doi: 10.6023/cjoc201512029
Abstract:
Recently, the asymmetric reduction of imines catalyzed by Lewis-basic organocatalyst has been received much attention as the cheap hydrogen source and the simple post treatment. Based on the different functional groups of organocatalysts, this paper introduced formamide, pyridine amide, sulfonamide, supported and other Lewis basic organocatalysts. The structural characteristics, catalytic activity and mechanism of the Lewis-basic organocatalysts were summarized.
Recently, the asymmetric reduction of imines catalyzed by Lewis-basic organocatalyst has been received much attention as the cheap hydrogen source and the simple post treatment. Based on the different functional groups of organocatalysts, this paper introduced formamide, pyridine amide, sulfonamide, supported and other Lewis basic organocatalysts. The structural characteristics, catalytic activity and mechanism of the Lewis-basic organocatalysts were summarized.
2016, 36(6): 1218-1228
doi: 10.6023/cjoc201512040
Abstract:
Organofluorine compounds are widely found in pharmaceuticals, agrochemicals, and materials due to their special properties. However, development of transformations to incorporate fluorine atom is usually a great challenge, because of its highly electronegative nature. Transition-metal catalyzed C—H bond fluorination has significant advantages in atom-economy, reaction diversity and environmental friendliness in comparison with the traditional transition-metal catalyzed cross-coupling approaches since it obviates the use of pre-functionalized substrates. In the past decade, C—H bond fluorination strategy has emerged as a powerful protocol to access new C—F bonds. This review presents the state of art for transition-metal catalyzed C—H bond fluorination. The existing problems and limitations of the field are summarized and the outlook of the area is also prospected.
Organofluorine compounds are widely found in pharmaceuticals, agrochemicals, and materials due to their special properties. However, development of transformations to incorporate fluorine atom is usually a great challenge, because of its highly electronegative nature. Transition-metal catalyzed C—H bond fluorination has significant advantages in atom-economy, reaction diversity and environmental friendliness in comparison with the traditional transition-metal catalyzed cross-coupling approaches since it obviates the use of pre-functionalized substrates. In the past decade, C—H bond fluorination strategy has emerged as a powerful protocol to access new C—F bonds. This review presents the state of art for transition-metal catalyzed C—H bond fluorination. The existing problems and limitations of the field are summarized and the outlook of the area is also prospected.
2016, 36(6): 1229-1240
doi: 10.6023/cjoc201510024
Abstract:
The electrophilic intermediate, vinylogous imine or vinylogous iminium, can be in situ generated from 3-indolyl- methanols under acidic conditions. With the aid of chiral catalysts, miscellaneous nucleophiles can attack these electrophilic intermediates to afford enantioenriched and biologically important 3-substituted indole derivatives. The recent advances of preparation of optically active indole derivatives from 3-indolylmethanols via asymmetric alkylation, asymmetric reduction and asymmetric rearrangement are summarized.
The electrophilic intermediate, vinylogous imine or vinylogous iminium, can be in situ generated from 3-indolyl- methanols under acidic conditions. With the aid of chiral catalysts, miscellaneous nucleophiles can attack these electrophilic intermediates to afford enantioenriched and biologically important 3-substituted indole derivatives. The recent advances of preparation of optically active indole derivatives from 3-indolylmethanols via asymmetric alkylation, asymmetric reduction and asymmetric rearrangement are summarized.
2016, 36(6): 1241-1265
doi: 10.6023/cjoc201511004
Abstract:
Ugi/de-Boc/cyclization (UDC) strategy represents a “three-step, one-pot procedure”, employing the Ugi multi-component reaction utilizing one bi-functional group substrates with N-Boc-protected amino, followed by Boc-deprotection and cyclization to synthesize nitrogen-containing heterocycles. This strategy has the characteristics of rapid, efficiency, economy and structural diversity, which can be used to build libraries of complex nitrogen-containing heterocycles and has drawn much attention recently. In this paper, the research progress of UDC strategy in the synthesis of five-, six- and seven-mem- bered heterocycles and natural products were summarized.
Ugi/de-Boc/cyclization (UDC) strategy represents a “three-step, one-pot procedure”, employing the Ugi multi-component reaction utilizing one bi-functional group substrates with N-Boc-protected amino, followed by Boc-deprotection and cyclization to synthesize nitrogen-containing heterocycles. This strategy has the characteristics of rapid, efficiency, economy and structural diversity, which can be used to build libraries of complex nitrogen-containing heterocycles and has drawn much attention recently. In this paper, the research progress of UDC strategy in the synthesis of five-, six- and seven-mem- bered heterocycles and natural products were summarized.
2016, 36(6): 1266-1286
doi: 10.6023/cjoc201511049
Abstract:
Lignin is the second most abundant natural polymer. Oxidative degradation of lignin polymer is a very promising approach in lignin valorisation, which offers the possibility to provide highly functional monomer and oligomer products in the chemical and pharmaceutical industries instead of fossil fuels used as the starting materials of the process of other valorisation. This paper focuses on the oxidative modification methods of lignin and its model compounds, including biocatalysis, biomimetic catalysis, organometallic catalysis, electrochemistry catalytic oxidation and several other oxidation methods, and a brief discussion of the reaction mechanism in the process of oxidative degradation.
Lignin is the second most abundant natural polymer. Oxidative degradation of lignin polymer is a very promising approach in lignin valorisation, which offers the possibility to provide highly functional monomer and oligomer products in the chemical and pharmaceutical industries instead of fossil fuels used as the starting materials of the process of other valorisation. This paper focuses on the oxidative modification methods of lignin and its model compounds, including biocatalysis, biomimetic catalysis, organometallic catalysis, electrochemistry catalytic oxidation and several other oxidation methods, and a brief discussion of the reaction mechanism in the process of oxidative degradation.
2016, 36(6): 1287-1298
doi: 10.6023/cjoc201512003
Abstract:
Lewis/Brønsted acid-catalyzed nucleophilic substitution of propargylic alcohols is very important in organic synthetic chemistry, which could be transformed into a variety of acyclic, carbocyclic and heterocyclic synthetic building blocks. A drawback of the traditional propargylation of Nicholas reaction is the generation of waste products resulting from displacement of the leaving group on treating with a catalyst and/or nucleophile. Therefore, the direct acid-catalyzed propargylation of propargylic alcohols is considered as a green method, which generated water as the only side product. In this review, the latest research progress on the Lewis and Brønsted acids catalyzed intermolecular and intramolecular propargylation of a variety of nucleophiles (NuH=C, N, O, S, I) with propargylic alcohols is presented. Finally, the problems and difficulties in research and application of propargylation of propargylic alcohols are discussed and then prospective is provided.
Lewis/Brønsted acid-catalyzed nucleophilic substitution of propargylic alcohols is very important in organic synthetic chemistry, which could be transformed into a variety of acyclic, carbocyclic and heterocyclic synthetic building blocks. A drawback of the traditional propargylation of Nicholas reaction is the generation of waste products resulting from displacement of the leaving group on treating with a catalyst and/or nucleophile. Therefore, the direct acid-catalyzed propargylation of propargylic alcohols is considered as a green method, which generated water as the only side product. In this review, the latest research progress on the Lewis and Brønsted acids catalyzed intermolecular and intramolecular propargylation of a variety of nucleophiles (NuH=C, N, O, S, I) with propargylic alcohols is presented. Finally, the problems and difficulties in research and application of propargylation of propargylic alcohols are discussed and then prospective is provided.
2016, 36(6): 1299-1307
doi: 10.6023/cjoc201512012
Abstract:
Cyclopentadiene and its derivatives are a type of important small molecule cyclic olefin compounds, which have been widely applied in many fields such as synthesis of metallocene compounds, synthesis of organic intermediates and organic photoelectric materials. Based on our recent research results, in this review, the research progress on the synthesis of cyclopentadiene derivatives and the application of some typical cyclopentadiene derivatives in the field of organic synthesis are summarized.
Cyclopentadiene and its derivatives are a type of important small molecule cyclic olefin compounds, which have been widely applied in many fields such as synthesis of metallocene compounds, synthesis of organic intermediates and organic photoelectric materials. Based on our recent research results, in this review, the research progress on the synthesis of cyclopentadiene derivatives and the application of some typical cyclopentadiene derivatives in the field of organic synthesis are summarized.
2016, 36(6): 1308-1315
doi: 10.6023/cjoc201602024
Abstract:
The aminoindan skeleton, which widely exists in natural products and drug molecules. A convenient approach, aza-Barbier reaction and intramolecular Heck reaction, was successfully developed for the construction of this skeleton. Enantioenriched 3-methylene-1-amino-2-indanol was also synthesized via this method.
The aminoindan skeleton, which widely exists in natural products and drug molecules. A convenient approach, aza-Barbier reaction and intramolecular Heck reaction, was successfully developed for the construction of this skeleton. Enantioenriched 3-methylene-1-amino-2-indanol was also synthesized via this method.
2016, 36(6): 1316-1324
doi: 10.6023/cjoc201602020
Abstract:
The research on aggregation-induced emission (AIE) has been a hot topic in the fields of photo-physics and luminescent materials. Design and synthesis of new AIE-active luminogens (AIEgens) will further promote the development of this area. Based on our developed new AIEgen of tetraphenylpyrazine (TPP), in this paper, we further enriched its family by covalently attaching thiophene unit on TPP core, and prepared three AIEgens of TPP-T, TPP-2T and T-TPP-T. Their structure-property relationship was studied in detail. The results showed that TPP-T, TPP-2T and T-TPP-T feature the aggregation-enhanced emission (AEE) characteristics. Their powders emit at 418, 437 and 436 nm with absolute fluorescence quantum yields of 26.8, 29.0 and 30.9%, respectively, which makes them promising to be used as emitting layer in fabrication of organic light-emitting diodes in combination with their excellent thermal stability.
The research on aggregation-induced emission (AIE) has been a hot topic in the fields of photo-physics and luminescent materials. Design and synthesis of new AIE-active luminogens (AIEgens) will further promote the development of this area. Based on our developed new AIEgen of tetraphenylpyrazine (TPP), in this paper, we further enriched its family by covalently attaching thiophene unit on TPP core, and prepared three AIEgens of TPP-T, TPP-2T and T-TPP-T. Their structure-property relationship was studied in detail. The results showed that TPP-T, TPP-2T and T-TPP-T feature the aggregation-enhanced emission (AEE) characteristics. Their powders emit at 418, 437 and 436 nm with absolute fluorescence quantum yields of 26.8, 29.0 and 30.9%, respectively, which makes them promising to be used as emitting layer in fabrication of organic light-emitting diodes in combination with their excellent thermal stability.
2016, 36(6): 1325-1334
doi: 10.6023/cjoc201512048
Abstract:
Columnar discotic liquid crystals have high charge carrier mobility, and donor-bridge-accepter-based supra-mole- cular compounds have photoinduced intramolecular electron transfer behavior. In order to make the organic materials possess these two performances, dyads composed of hexaalkoxy triphenylene unit and perylene monoimide diesters unit were prepared in this work. In the dyads, the flexible alkoxys were used as bridges, the triphenylene units having six electron-donating alkoxy tails acted as electron donors, and the perylene monoimide diesters units having four electron-withdrawing carbonyls acted as electron acceptors. Their structures were established by proton nuclear magnetic resonance (1H NMR), infrared spectroscopy (IR), mass spectrometry (MS) and elemental analysis (EA). The photophysical properties were characterized by means of UV-Vis absorption spectroscopy and fluorescence spectroscopy. The results showed that in dilute dichloromethane solutions the absorbance strength of these dyads was the sum of that of their monomers, hexakishexyloxy triphenylene (HAT6) and N-hexyl-perylene monoimide dihexyl esters (PMD6), and not interfered by the length of flexible bridges. When excited at 475 nm, the strength of the fluorescence of the dyads decreased when the spacers shortened from dodecyloxy, decyloxy, hexyloxy to ethoxy groups. Actually, when the spacer was ethoxy group, the fluorescence of the dyad was almost quenched completely. This is attributed to the photoinduced electron transfer properties (PET) between the donor and acceptor units. When excited at 280 nm, the strength of the fluorescence of the triphenylene units also became weaker when the spacers shortened from dodecyloxy to ethanyloxy. At the same time, the strength of the fluorescence of the perylene units became stronger. This is attributed to energy transfer from the triphenylene unit to the perylene unit. In addition, their liquid crystalline properties have been studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The results demonstrated that when the spacers were decyloxy and dodecyloxy the dyads possessed columnar liquid crystal behavior in the heating circle, while in the cooling circle only the dyad bearing the dodecyloxy spacer showed mesophase; and dyads bridged by the hexyloxy or ethanyloxy did not show liquid crystal properties in the heating or cooling circle. Electronic energy levels of triphenylene and perylene units of the dyads measured by cyclic voltammetry (CV) are almost the same as that of HAT6 and PMD6, respectively. In conclusion, these dyads have the potential application in the organic photovoltaic field.
Columnar discotic liquid crystals have high charge carrier mobility, and donor-bridge-accepter-based supra-mole- cular compounds have photoinduced intramolecular electron transfer behavior. In order to make the organic materials possess these two performances, dyads composed of hexaalkoxy triphenylene unit and perylene monoimide diesters unit were prepared in this work. In the dyads, the flexible alkoxys were used as bridges, the triphenylene units having six electron-donating alkoxy tails acted as electron donors, and the perylene monoimide diesters units having four electron-withdrawing carbonyls acted as electron acceptors. Their structures were established by proton nuclear magnetic resonance (1H NMR), infrared spectroscopy (IR), mass spectrometry (MS) and elemental analysis (EA). The photophysical properties were characterized by means of UV-Vis absorption spectroscopy and fluorescence spectroscopy. The results showed that in dilute dichloromethane solutions the absorbance strength of these dyads was the sum of that of their monomers, hexakishexyloxy triphenylene (HAT6) and N-hexyl-perylene monoimide dihexyl esters (PMD6), and not interfered by the length of flexible bridges. When excited at 475 nm, the strength of the fluorescence of the dyads decreased when the spacers shortened from dodecyloxy, decyloxy, hexyloxy to ethoxy groups. Actually, when the spacer was ethoxy group, the fluorescence of the dyad was almost quenched completely. This is attributed to the photoinduced electron transfer properties (PET) between the donor and acceptor units. When excited at 280 nm, the strength of the fluorescence of the triphenylene units also became weaker when the spacers shortened from dodecyloxy to ethanyloxy. At the same time, the strength of the fluorescence of the perylene units became stronger. This is attributed to energy transfer from the triphenylene unit to the perylene unit. In addition, their liquid crystalline properties have been studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The results demonstrated that when the spacers were decyloxy and dodecyloxy the dyads possessed columnar liquid crystal behavior in the heating circle, while in the cooling circle only the dyad bearing the dodecyloxy spacer showed mesophase; and dyads bridged by the hexyloxy or ethanyloxy did not show liquid crystal properties in the heating or cooling circle. Electronic energy levels of triphenylene and perylene units of the dyads measured by cyclic voltammetry (CV) are almost the same as that of HAT6 and PMD6, respectively. In conclusion, these dyads have the potential application in the organic photovoltaic field.
2016, 36(6): 1335-1340
doi: 10.6023/cjoc201512050
Abstract:
A facile method for the synthesis of tetrahydropyrimidines is described. Diethylamine was treated with methyl propiolate to provide Michael adduct (β-amino acrylate). In the presence of organic acid, the cyclization of imines with β-aminoacrylateoccurred at room temperature and completed within several minutes to give tetrahydropyrimidines with liberation of ammonium salt. Formaldimines show good toleration to the reaction.
A facile method for the synthesis of tetrahydropyrimidines is described. Diethylamine was treated with methyl propiolate to provide Michael adduct (β-amino acrylate). In the presence of organic acid, the cyclization of imines with β-aminoacrylateoccurred at room temperature and completed within several minutes to give tetrahydropyrimidines with liberation of ammonium salt. Formaldimines show good toleration to the reaction.
Palladium-Catalyzed Ligand-Free Suzuki Reaction of Potassium Aryltrifluoroborates in Aqueous Ethanol
2016, 36(6): 1341-1350
doi: 10.6023/cjoc201601001
Abstract:
A simple and ligand-free protocol has been developed for the Pd(OAc)2-catalyzed Suzuki reaction of potassium aryltrifluoroborates in aqueous ethanol under air. In the presence of Pd(OAc)2 and 1 equiv. of K2CO3, aryl or heteroaryl halides coupled with various potassium aryltrifluoroborates smoothly to afford the products in high yields with the highest turnover frequency (TOF) up to 4656 h-1, and a series of triphenylamine derivatives were prepared efficiently in this system. In addition, the active catalyst was proved to be the in situ-generated palladium nanoparticles according to TEM analysis and mercury-poisoning test.
A simple and ligand-free protocol has been developed for the Pd(OAc)2-catalyzed Suzuki reaction of potassium aryltrifluoroborates in aqueous ethanol under air. In the presence of Pd(OAc)2 and 1 equiv. of K2CO3, aryl or heteroaryl halides coupled with various potassium aryltrifluoroborates smoothly to afford the products in high yields with the highest turnover frequency (TOF) up to 4656 h-1, and a series of triphenylamine derivatives were prepared efficiently in this system. In addition, the active catalyst was proved to be the in situ-generated palladium nanoparticles according to TEM analysis and mercury-poisoning test.
2016, 36(6): 1351-1358
doi: 10.6023/cjoc201601025
Abstract:
3-Indolyl methanamine derivatives have attracted much attention due to their multiple potent bioactivities. The Friedel-Crafts reaction between indole and N-sulfonylaldimine is a major method for preparation of 3-indolyl methanamine derivatives, however, abundant bisindolyl methane will be formed during the reaction. 3-Indolylmethanamine derivatives were selectively synthesized in 65%~93% yields by the Friedel-Crafts amidoalkylation reaction of indoles and N-sulfonylaldimines utilizing Cu(OTf)2 and N-sulfinylprolinamide as catalysts. This method exhibited several features such as broad substrate applicability, mild reaction condition and simple operation.
3-Indolyl methanamine derivatives have attracted much attention due to their multiple potent bioactivities. The Friedel-Crafts reaction between indole and N-sulfonylaldimine is a major method for preparation of 3-indolyl methanamine derivatives, however, abundant bisindolyl methane will be formed during the reaction. 3-Indolylmethanamine derivatives were selectively synthesized in 65%~93% yields by the Friedel-Crafts amidoalkylation reaction of indoles and N-sulfonylaldimines utilizing Cu(OTf)2 and N-sulfinylprolinamide as catalysts. This method exhibited several features such as broad substrate applicability, mild reaction condition and simple operation.
2016, 36(6): 1359-1367
doi: 10.6023/cjoc201511037
Abstract:
Diacylglycerol acyltransferase (DGAT), the only limited enzyme in the synthesis of triacylglycerol (TAG), is regarded as an important therapeutic target for human obesity and other metabolic syndromes. Compounds 5~8 were designed and synthesized, in which the lactone group of aphadilactone C was introduced into the PF-04620110 and AZD-7687, which have entered into the clinical research, to verify whether the lactone in aphadilactone C played the same role as carboxylic group in PF-04620110 and AZD-7687. The final vitro assay showed that compounds 5~8 have not the inhibition activity to DGAT1. This might suggest that inhibition mechanism of aphadilactone C was not the same as PF-04620110 and AZD-7687.
Diacylglycerol acyltransferase (DGAT), the only limited enzyme in the synthesis of triacylglycerol (TAG), is regarded as an important therapeutic target for human obesity and other metabolic syndromes. Compounds 5~8 were designed and synthesized, in which the lactone group of aphadilactone C was introduced into the PF-04620110 and AZD-7687, which have entered into the clinical research, to verify whether the lactone in aphadilactone C played the same role as carboxylic group in PF-04620110 and AZD-7687. The final vitro assay showed that compounds 5~8 have not the inhibition activity to DGAT1. This might suggest that inhibition mechanism of aphadilactone C was not the same as PF-04620110 and AZD-7687.
2016, 36(6): 1368-1374
doi: 10.6023/cjoc201512008
Abstract:
In order to develop new potent anti-phytopathogenic fungi drugs, a series of 2-sulfanylidene-2,3-dihydroquinazo- line-4(1H)-ones were synthesized under ultrasonic irradiation. Structures of the compounds were characterized by IR, 1H NMR, 13C NMR and MS. All compounds were investigated for anti-phytopathogenic fungi activity via the method of minimum inhibitory concentrations. The majority of compounds exhibited a good inhibitory activity to Alternaria brassicae and Colletotrichum gloeosporioides. The minimum inhibitory concentrations of compounds 3a, 3b, 3g and 3h were 16 μg/mL, which showed significant inhibitory activity to Alternaria brassicae compared with that of the positive control drug ketoconazole.
In order to develop new potent anti-phytopathogenic fungi drugs, a series of 2-sulfanylidene-2,3-dihydroquinazo- line-4(1H)-ones were synthesized under ultrasonic irradiation. Structures of the compounds were characterized by IR, 1H NMR, 13C NMR and MS. All compounds were investigated for anti-phytopathogenic fungi activity via the method of minimum inhibitory concentrations. The majority of compounds exhibited a good inhibitory activity to Alternaria brassicae and Colletotrichum gloeosporioides. The minimum inhibitory concentrations of compounds 3a, 3b, 3g and 3h were 16 μg/mL, which showed significant inhibitory activity to Alternaria brassicae compared with that of the positive control drug ketoconazole.
2016, 36(6): 1375-1381
doi: 10.6023/cjoc201512038
Abstract:
The oxidative coupling and aromatization of 3,4-dihydropyrimidin-2-thiones to produce 1,2-di(pyrimidin-2-yl)- disulfides by using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant at room temperature under an air atmosphere are reported. Compared with the reported procedures, this method has obvious advantages at mild reaction conditions including lower reaction temperature and shorter reaction time with higher yields of products.
The oxidative coupling and aromatization of 3,4-dihydropyrimidin-2-thiones to produce 1,2-di(pyrimidin-2-yl)- disulfides by using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant at room temperature under an air atmosphere are reported. Compared with the reported procedures, this method has obvious advantages at mild reaction conditions including lower reaction temperature and shorter reaction time with higher yields of products.
2016, 36(6): 1382-1388
doi: 10.6023/cjoc201601003
Abstract:
A series of α-ketoamide derivatives were obtained from the palladium catalyzed oxidation of ynamides using cheap and readily available dimethyl sulfoxide as oxidant and solvent under room temperature. The structures of all products were characterized by 1H NMR, 13C NMR, IR and HRMS. This protocol has some distinct advantages of mild conditions, simple work-up, readily available starting materials and fast reaction rate.
A series of α-ketoamide derivatives were obtained from the palladium catalyzed oxidation of ynamides using cheap and readily available dimethyl sulfoxide as oxidant and solvent under room temperature. The structures of all products were characterized by 1H NMR, 13C NMR, IR and HRMS. This protocol has some distinct advantages of mild conditions, simple work-up, readily available starting materials and fast reaction rate.
2016, 36(6): 1389-1394
doi: 10.6023/cjoc201512016
Abstract:
A novel carbazole sulfonamide-based anion receptor (L) containing the aminoanthraquinone signalling units was designed and synthesized, which was characterized by 1H NMR, 13C NMR, MS, IR and elemental analysis. The obtained results from UV-Vis and fluorescence titrations indicated that receptor L realized a highly selective recognition of F- via the formation of a 1:1 H-bonding complex. Moreover, the presence of F- induced a significant fluorescent quenching and a color change (from red to purple-red) of dimethyl sulfoxide (DMSO) solution of L, suggesting its potential as fluorescent and colorimetric sensors for the detection of F-.
A novel carbazole sulfonamide-based anion receptor (L) containing the aminoanthraquinone signalling units was designed and synthesized, which was characterized by 1H NMR, 13C NMR, MS, IR and elemental analysis. The obtained results from UV-Vis and fluorescence titrations indicated that receptor L realized a highly selective recognition of F- via the formation of a 1:1 H-bonding complex. Moreover, the presence of F- induced a significant fluorescent quenching and a color change (from red to purple-red) of dimethyl sulfoxide (DMSO) solution of L, suggesting its potential as fluorescent and colorimetric sensors for the detection of F-.
2016, 36(6): 1395-1400
doi: 10.6023/cjoc201511048
Abstract:
A series of phenothiazine (or triphenylamine)-substituted imidazoles were designed and synthesized as new organic fluorescent molecules by multi-step reactions. The relationship of their photoluminescence properties and structure was investigated via UV-Vis, fluorescence and electrochemical analyzer. Their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) distributions were calculated by density functional theory (DFT) (B3LYP; 6-31G*) calculations. The high fluorescence quantum yields, desirable HOMO levels and high thermal stabilities of products indicated that the combination of imidazole and phenothiazines or triphenylamine is an efficient way to enhance hole transporting ability and fluorescent quantum yield.
A series of phenothiazine (or triphenylamine)-substituted imidazoles were designed and synthesized as new organic fluorescent molecules by multi-step reactions. The relationship of their photoluminescence properties and structure was investigated via UV-Vis, fluorescence and electrochemical analyzer. Their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) distributions were calculated by density functional theory (DFT) (B3LYP; 6-31G*) calculations. The high fluorescence quantum yields, desirable HOMO levels and high thermal stabilities of products indicated that the combination of imidazole and phenothiazines or triphenylamine is an efficient way to enhance hole transporting ability and fluorescent quantum yield.
2016, 36(6): 1401-1406
doi: 10.6023/cjoc201512033
Abstract:
A new pyrazoline derivative 1-(2-hydroxyphenyl)-4-(9-anthryl)-3-benzothiazole pyrazolin (P1) was designed and synthesized. The recognition properties of the target compound P1 with metal ions had been investigated by UV absorption and fluorescence spectrophotometry. The probe exhibits several favorable features, including instantaneous, reversible recognition, high sensitivity and selectivity to copper ions. Cytotoxicity test and fluorescent immunoassay results show that compound P1 has good biocompatibility and low toxicity with its IC50 value of 376.558 μmol/L.
A new pyrazoline derivative 1-(2-hydroxyphenyl)-4-(9-anthryl)-3-benzothiazole pyrazolin (P1) was designed and synthesized. The recognition properties of the target compound P1 with metal ions had been investigated by UV absorption and fluorescence spectrophotometry. The probe exhibits several favorable features, including instantaneous, reversible recognition, high sensitivity and selectivity to copper ions. Cytotoxicity test and fluorescent immunoassay results show that compound P1 has good biocompatibility and low toxicity with its IC50 value of 376.558 μmol/L.
2016, 36(6): 1407-1411
doi: 10.6023/cjoc201601010
Abstract:
An efficient melting method for the synthesis of β-indole derivatives via Yonemitsu reaction was developed successfully using aldehyde, indole and Meldrum's acid as the starting materials and 50 μL water as green promoter without other solvent. A series of 5-[(indole-3-yl)-arylmethyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives were synthesized in 55%~94% yields. The remarkable advantages of this reaction were mild reaction condition, easy operation, tolerant the substrates with diverse functional groups and environment-friendly.
An efficient melting method for the synthesis of β-indole derivatives via Yonemitsu reaction was developed successfully using aldehyde, indole and Meldrum's acid as the starting materials and 50 μL water as green promoter without other solvent. A series of 5-[(indole-3-yl)-arylmethyl]-2,2-dimethyl-1,3-dioxane-4,6-dione derivatives were synthesized in 55%~94% yields. The remarkable advantages of this reaction were mild reaction condition, easy operation, tolerant the substrates with diverse functional groups and environment-friendly.
Preparation and Catalytic Properties of a Novel Bamboo Fiber Supported-Palladium Catalyst (Fiber-Pd)
2016, 36(6): 1412-1418
doi: 10.6023/cjoc201510037
Abstract:
A novel bamboo fiber supported palladium (Fiber-Pd) catalyst was prepared with diphenylphosphinite fiber and palladium dichloride in ethanol. The as-prepared Fiber-Pd catalyst was characterized by X-ray photoelectron spectrometer (XPS), X-ray diffraction (XRD), thermogravimetric analyses (TGA), inductively coupled plasma-atomic emission spectrometry (ICP-AES), and transmission electron microscopy (TEM). The catalyst was applied to the Suzuki cross-coupling reaction between sodium tetraarylborate and aryl halides. Excellent yields of the corresponding functionalized biaryls were obtained when the reaction was performed in the presence of NaHCO3 as base in PEG 400/H2O at 85 ℃ within a short reaction time. It is noteworthy that the present protocol is highly efficient as 4 equiv. aryl halides reacted with 1 equiv. sodium tetraarylborate cleanly to provide high yield of the cross-coupling products in short reaction time. The catalyst can be easily separated and recovered from the reaction mixture by filtration and reused. This process has significant features of short reaction time, broad substrate scopes, easy isolation of the product, and atom-efficient coupling under mild conditions in environmentally friendly media in air.
A novel bamboo fiber supported palladium (Fiber-Pd) catalyst was prepared with diphenylphosphinite fiber and palladium dichloride in ethanol. The as-prepared Fiber-Pd catalyst was characterized by X-ray photoelectron spectrometer (XPS), X-ray diffraction (XRD), thermogravimetric analyses (TGA), inductively coupled plasma-atomic emission spectrometry (ICP-AES), and transmission electron microscopy (TEM). The catalyst was applied to the Suzuki cross-coupling reaction between sodium tetraarylborate and aryl halides. Excellent yields of the corresponding functionalized biaryls were obtained when the reaction was performed in the presence of NaHCO3 as base in PEG 400/H2O at 85 ℃ within a short reaction time. It is noteworthy that the present protocol is highly efficient as 4 equiv. aryl halides reacted with 1 equiv. sodium tetraarylborate cleanly to provide high yield of the cross-coupling products in short reaction time. The catalyst can be easily separated and recovered from the reaction mixture by filtration and reused. This process has significant features of short reaction time, broad substrate scopes, easy isolation of the product, and atom-efficient coupling under mild conditions in environmentally friendly media in air.
2016, 36(6): 1419-1425
doi: 10.6023/cjoc201512034
Abstract:
The telomere-associated protein tankyrase is a poly(adenosine diphosphate-ribose) polymerase and is considered to be a promising target for cancer therapy, especially selective lethality on breast cancer associated (BRCA) cell lines, including breast cancer as well as malignancies of the ovaries, pancreas, and prostate gland. A variety of drug candidates have been developed and investigated, such as XAV-939, which was identified as a tankyrase inhibitor during screening for a small-mole- cule inhibitor of the Wnt/β-catenin pathway, and it exhibits nanomolar activity in the tankyrase-2 biochemical assay. Coincidentally, almost all compounds which exhibit excellent activity in the tankyrase-2 biochemical assay showed the common structure: lactam ring or amide structure. According to the reported co-crystal structure of inhibitors with tankyrase-2 analysis, it was found that the lactam ring or amide of the compounds forms three conserved hydrogen bonds to Gly1032 and Ser1068 and a π-stacking interaction with Tyr1071. Thus the lactam ring or amide was identified to be a key structure of tankyrase inhibitors. So a new class of structure based on benzo[f][1,4]oxazepinone scaffold was designed through computer-aided virtual drug screening, and 12 new compounds were synthesized via Mannich reactions of aromatic aldehydes with aromatic amines and aromatic ketones, ring expansion, reduction and condensation. The target compound was confirmed by 1H NMR, 13C NMR, HRMS. Followed by the methyl thiazolyl tetrazolium (MTT) assay [A1] to test in vitro anti-tumor activity, part compounds showed potent inhibitory effect on tumor cells. This study culminates in compound 3h, an inhibitor with potent activity against Hep-3B (IC50=3.5 μmol/L). Here, the synthesis and structure-activity relationship (SAR) of this novel series were described. To explore the anti-tumor mechanism of benzo[f][1,4]oxazepinone compounds, we explored the interaction of the compound 3h complex with the Gly1032, Ser1068 and Tyr1071 binding site of tankyrase-2, which confirms the three conserved hydrogen and π-stacking binding mode, as supporting information for the in vitro anti-tumor activity.
The telomere-associated protein tankyrase is a poly(adenosine diphosphate-ribose) polymerase and is considered to be a promising target for cancer therapy, especially selective lethality on breast cancer associated (BRCA) cell lines, including breast cancer as well as malignancies of the ovaries, pancreas, and prostate gland. A variety of drug candidates have been developed and investigated, such as XAV-939, which was identified as a tankyrase inhibitor during screening for a small-mole- cule inhibitor of the Wnt/β-catenin pathway, and it exhibits nanomolar activity in the tankyrase-2 biochemical assay. Coincidentally, almost all compounds which exhibit excellent activity in the tankyrase-2 biochemical assay showed the common structure: lactam ring or amide structure. According to the reported co-crystal structure of inhibitors with tankyrase-2 analysis, it was found that the lactam ring or amide of the compounds forms three conserved hydrogen bonds to Gly1032 and Ser1068 and a π-stacking interaction with Tyr1071. Thus the lactam ring or amide was identified to be a key structure of tankyrase inhibitors. So a new class of structure based on benzo[f][1,4]oxazepinone scaffold was designed through computer-aided virtual drug screening, and 12 new compounds were synthesized via Mannich reactions of aromatic aldehydes with aromatic amines and aromatic ketones, ring expansion, reduction and condensation. The target compound was confirmed by 1H NMR, 13C NMR, HRMS. Followed by the methyl thiazolyl tetrazolium (MTT) assay [A1] to test in vitro anti-tumor activity, part compounds showed potent inhibitory effect on tumor cells. This study culminates in compound 3h, an inhibitor with potent activity against Hep-3B (IC50=3.5 μmol/L). Here, the synthesis and structure-activity relationship (SAR) of this novel series were described. To explore the anti-tumor mechanism of benzo[f][1,4]oxazepinone compounds, we explored the interaction of the compound 3h complex with the Gly1032, Ser1068 and Tyr1071 binding site of tankyrase-2, which confirms the three conserved hydrogen and π-stacking binding mode, as supporting information for the in vitro anti-tumor activity.
2016, 36(6): 1426-1430
doi: 10.6023/cjoc201511028
Abstract:
Berberine chloride was synthesized starting from pyrocatechol in overall 13.6% yield. The key steps include a Hofmann rearrangement, chloromethylation, nucleophilic substitution, hydrolysis, decarboxylation, and cyclization. All of intermediates were determined by 1H NMR, 13C NMR, MS techniques.
Berberine chloride was synthesized starting from pyrocatechol in overall 13.6% yield. The key steps include a Hofmann rearrangement, chloromethylation, nucleophilic substitution, hydrolysis, decarboxylation, and cyclization. All of intermediates were determined by 1H NMR, 13C NMR, MS techniques.
2016, 36(6): 1431-1437
doi: 10.6023/cjoc201512019
Abstract:
In order to find novel cyanoacrylate lead compounds, 17 new cyanoacrylate compounds bearing fluoride methyl pyrazole moiety were synthesized by the method of active substructure combination. They were structurally confirmed by 1H NMR, 13C NMR and elemental analysis. The structures of compounds 7b, 7f, 7j and 7o were also tested through MS technique. Preliminary bioassay data showed that some of the target compounds displayed important anti-tumor activities.
In order to find novel cyanoacrylate lead compounds, 17 new cyanoacrylate compounds bearing fluoride methyl pyrazole moiety were synthesized by the method of active substructure combination. They were structurally confirmed by 1H NMR, 13C NMR and elemental analysis. The structures of compounds 7b, 7f, 7j and 7o were also tested through MS technique. Preliminary bioassay data showed that some of the target compounds displayed important anti-tumor activities.
2016, 36(6): 1438-1443
doi: 10.6023/cjoc201511015
Abstract:
Microwave irradiation technology was used to assist the conversion of cellulose to methyl levulinate (ML) in methanol solution in the presence of mixed catalysts. The reactions were carried out in a microwave reactor and cellulose was rapidly converted into ML with a highest yield of 61.5% by the use of SnCl4/H2SO4 as catalyst. The catalysts ratios, reaction time and reaction temperature were optimized and found to have great influences on both the ML product yield and the selectivity. Besides, an appropriate amount of water, which may participate the breakage of the glucosidic bond of cellulose, is highly desirable for the full conversion of cellulose. Several other biomass derived carbohydrates such as starch, sucrose and inulin were also tested in the optimized system and 48%~60% ML yields were achieved. Finally, the mixed catalysts can be recycled and reused for at least five times without much decrease in catalytic activity.
Microwave irradiation technology was used to assist the conversion of cellulose to methyl levulinate (ML) in methanol solution in the presence of mixed catalysts. The reactions were carried out in a microwave reactor and cellulose was rapidly converted into ML with a highest yield of 61.5% by the use of SnCl4/H2SO4 as catalyst. The catalysts ratios, reaction time and reaction temperature were optimized and found to have great influences on both the ML product yield and the selectivity. Besides, an appropriate amount of water, which may participate the breakage of the glucosidic bond of cellulose, is highly desirable for the full conversion of cellulose. Several other biomass derived carbohydrates such as starch, sucrose and inulin were also tested in the optimized system and 48%~60% ML yields were achieved. Finally, the mixed catalysts can be recycled and reused for at least five times without much decrease in catalytic activity.
