Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomer...Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.展开更多
Borylation of 1,3-enynes with bis(boronate)compounds often ends up with the formation of hydroborylated products,leaving the diborylation of 1,3-enynes for the formation of 1,4-diborylated allenes to be challenging.He...Borylation of 1,3-enynes with bis(boronate)compounds often ends up with the formation of hydroborylated products,leaving the diborylation of 1,3-enynes for the formation of 1,4-diborylated allenes to be challenging.Herein,a copper-catalyzed chemo-,regio-,and stereo-selective diborylation of 1,3-enynes for the efficient construction of 1,4-diborylated allenes under base-free conditions was reported.A wide range of 1,3-enynes bearing various functional groups can participant in the reaction and afforded the corresponding 1,4-diborylated allenes in good to excellent yields,which was enabled by the protocol of Bpin to BF3K conversion.the borylcopper species was supposed to selectively attack the C-C triple bond of the 1,3-enynes.展开更多
Permanganate has attracted much attention in wide range of chemistry and particularly in degradation of environmental pollutants.However,few studies have discussed the feature of regioselective reactivity of permangan...Permanganate has attracted much attention in wide range of chemistry and particularly in degradation of environmental pollutants.However,few studies have discussed the feature of regioselective reactivity of permanganate with specific moiety of the target compound.Herein,we studied the reaction between permanganate and tetracycline that is an emerging micropollutant with different species containing several electron-rich groups.The second-order rate constants increased from 6.0 to 9.0 and could be quantitatively modeled by considering the speciation of both reactants,yielding kTC0=11.7(mol/L)^-1 sec^-1,kTC-=35.7(mol/L)^-1 sec^-1,kTC2-=43.1(mol/L)^-1 sec^-1 for individual reaction channels.Degradation products were then identified as the hydroxylated and demethylated compounds.The result suggested a rate-limiting step of simple hydroxylation at the phenolic and/or alkene moieties,while the demethylation should be caused by the unavoidably formed manganese oxide via single electron oxidation.This is supported by the DFT calculation,indicating the primary oxidation of phenolic group of TC0 with activation barrier of 44.5 kcal/mol and of alkene group of TC-and TC2-with activation barriers of 44.0 and 43.4 kcal/mol,respectively.This is in agreement with the experimental results,implying the alternation of regioselectivity associated with the deprotonation process.The result was further supported by performing the Fukui function and electrostatic potential analysis,reflecting the more probable site and better electron donating tendency beneficial to the permanganate oxidation.展开更多
Reaction of activated aromatics containing phenobs, naphthol, methoxynaphthalenes,anisole etc. with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the correspondin...Reaction of activated aromatics containing phenobs, naphthol, methoxynaphthalenes,anisole etc. with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding monobromination products with excellent yields.展开更多
Synthetic studies on the construction of 7-O-methylquercetin from quercetin in 36% yield in four steps is reported, this strategy relies on one hand on the selective protection of the catechol group with dichlorodiphe...Synthetic studies on the construction of 7-O-methylquercetin from quercetin in 36% yield in four steps is reported, this strategy relies on one hand on the selective protection of the catechol group with dichlorodiphenylmethane using dephenyl ether as a solvent, on the other hand, on the selective protection of the 3-hydroxyl group with benzyl bromide, these two different protecting groups can be removed under the same hydrogenation.展开更多
The first three-component and regioselective synthesis of pyridazinones and phthalazinones from arenes,anhydrides and ArNHNH;in the presence of efficient recyclable heterogeneous catalyst,montmorillonite-KSF,in high y...The first three-component and regioselective synthesis of pyridazinones and phthalazinones from arenes,anhydrides and ArNHNH;in the presence of efficient recyclable heterogeneous catalyst,montmorillonite-KSF,in high yield and short reaction time is reported.展开更多
An efficient triethylamine-catalyzed synthesis of 4-amino-3,5-dicyano-6-arylphthalates is described.A one-pot,simple pseudo four-component reaction between arylaldehydes,dialkyl acetylenedicarboxylates, and twice as m...An efficient triethylamine-catalyzed synthesis of 4-amino-3,5-dicyano-6-arylphthalates is described.A one-pot,simple pseudo four-component reaction between arylaldehydes,dialkyl acetylenedicarboxylates, and twice as much malononitrile gave 4-amino-3,5-dicyano-6-arylphthalates in good to excellent yields.展开更多
The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discu...The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discussed.展开更多
In this study, 1-（1-alkylsulfonic）-3-methylimidazolium chloride as a new, green, and reusable Br？nsted acid catalyst was prepared. In this protocol, we used for the regioselective ring-opening reactions of various ...In this study, 1-（1-alkylsulfonic）-3-methylimidazolium chloride as a new, green, and reusable Br？nsted acid catalyst was prepared. In this protocol, we used for the regioselective ring-opening reactions of various epoxiodes with sodium azide to afford the corresponding b-azido alcohols in excellent yields and short reaction time under mild and neutral reaction conditions. This method offers several advantages including excellent regioselectivity, clean reactions, simple work-up procedure, a recyclable catalyst,and use of an eco-friendly catalyst.展开更多
An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylalde...An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times（3-4 min） and excellent yields（87-95%）.展开更多
Cellulose nanofibrils(CNFs)are promising sustainable materials that can be applied to nanocomposites,as well as medical and life-sciences devices.However,methods for the preparation of these important materials are en...Cellulose nanofibrils(CNFs)are promising sustainable materials that can be applied to nanocomposites,as well as medical and life-sciences devices.However,methods for the preparation of these important materials are energy intensive because heating and mechanical disintegration are required to produce cellulose fibers below 100 nm in size.In this study,CNFs were prepared through the multi-site regioselective oxidation of cellulose with 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)and periodate at room temperature(20–25°C),without any mechanical-disintegration treatment.Transmission electron microscopy(TEM)revealed that the CNFs had the average widths of 14.1,55.4,and 81.9 nm for three different treatments.Fourier-transform infrared spectroscopy revealed that carboxyl groups were created on the surfaces of the microfibrils,while X-ray diffraction studies showed that the cellulose I structure was maintained after oxidation,and that the cellulose nanofibril crystallinity index exceeded 70%.These results demonstrate that CNFs can be prepared by multi-site regioselective oxidation at room temperature in the absence of mechanical disintegration.In addition,a model was developed to calculate the total content of carboxylate and aldehyde groups of CNFs prepared by the TEMPO mediate oxidation,the periodate oxidation,and the multi-site regioselective oxidation methods based on the particle width determined by TEM.The calculated values of the model were in good agreement with the total content(experimental value)of carboxylate and aldehyde groups of CNFs prepared by the TEMPO-mediated oxidation and the multi-site regioselective oxidation methods.However,the model was not valid for CNFs prepared by the periodate oxidation method.展开更多
The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. T...The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.展开更多
A novel and efficient route of synthesizing 1, 2, 4-triazoline-5-ones is reported. The title compounds can be prepared in high yield and purity by the one-pot oxidation and cyclization of 1-acylthiosemicarbazides. The...A novel and efficient route of synthesizing 1, 2, 4-triazoline-5-ones is reported. The title compounds can be prepared in high yield and purity by the one-pot oxidation and cyclization of 1-acylthiosemicarbazides. The reaction is regioselective and stereoselective. The reaction condition is mild.展开更多
A concise and efficient approach was developed for the synthesis of pentacyclic compounds containing coumarin, pyrrole, indene in a regioselective manner in good yields via the reactions of N-substituted 4- aminocouma...A concise and efficient approach was developed for the synthesis of pentacyclic compounds containing coumarin, pyrrole, indene in a regioselective manner in good yields via the reactions of N-substituted 4- aminocoumarin compounds and ninhydrin using microwave irradiation. No catalysts are required in our protocol.展开更多
Di-O-acetyl sucrose was regioselective synthesized by using dibutyltin oxide in about 60% yield. The structure of acetyl derivative was elucidated by 1H NMR, 13C NMR, 2D-NMR and MS spectral data.
Semi-synthesis of paclitaxel was achieved in four steps from 10-deacetylbaccatin HI （10-DAB HI）. The key steps are the regioselective protection at the hydroxyl group at C-7 of 10-DAB HI, using 1,1′-thiocarbonyldii...Semi-synthesis of paclitaxel was achieved in four steps from 10-deacetylbaccatin HI （10-DAB HI）. The key steps are the regioselective protection at the hydroxyl group at C-7 of 10-DAB HI, using 1,1′-thiocarbonyldiimidazole as a selective reagent, and the deprotection of the protected paclitaxel with a mixture of p-toluenesulfonic acid and 0.1 mol/L aqueous hydrochloride.展开更多
Regioselective decomposition of 11-substituted- 16α, 17α-methyleneazopregna- 1,4-dien- 3, 20-dione Ⅰ proceeded smoothly through thermal decomposition in the presence of BF3·Et2O or HClO4 with high yields. Ⅰ w...Regioselective decomposition of 11-substituted- 16α, 17α-methyleneazopregna- 1,4-dien- 3, 20-dione Ⅰ proceeded smoothly through thermal decomposition in the presence of BF3·Et2O or HClO4 with high yields. Ⅰ was converted to 11-substituted-16-methylpregna-1, 4, 16（17）-trien-3, 20-dione Ⅱ by the thermal decomposition, while with HClO4 ad a catalyst, 11-substituted-16α, 17α-methylenepregna-1, 4-dien-3, 20-dione Ⅲ was the main product. However, when BF3·Et2O was used as catalyst, a mixture of Ⅱ and Ⅲ（1 ： 3） was obtained.展开更多
A simultaneous C2-H arylation and C8-H alkylation of naphthalene ring has been achieved by palladiumcatalyzed cascade reaction of N-(2-halophenyl)-2-(naphthalen-1-yl)acrylamides with aryl iodides,which provides an eff...A simultaneous C2-H arylation and C8-H alkylation of naphthalene ring has been achieved by palladiumcatalyzed cascade reaction of N-(2-halophenyl)-2-(naphthalen-1-yl)acrylamides with aryl iodides,which provides an efficient method for synthesizing various aryl-substituted spirocyclic oxindoles.The protocol enables three C-C bonds formation via an intramolecular Heck reaction and sequentially regioselective C-H bond activation.展开更多
This report presents a detailed density functional theory （DFT） study on the difference in regioselectivity for the copolymerization reactions of styrene oxide versus propylene oxide with CO2 utilizing binary （sale...This report presents a detailed density functional theory （DFT） study on the difference in regioselectivity for the copolymerization reactions of styrene oxide versus propylene oxide with CO2 utilizing binary （salen）cobalt（III） catalyst systems. This study focuses on the discrepancy of regioselective ring-opening of two terminal epoxides during the copolymerization with CO2. It was found that the nucleophilic ring-opening of styrene oxide occurred predominantly at the methine C a--O bond due to the election delocalization of phenyl group to stabilize the transition state for the methine C--O bond cleavage.展开更多
The facile and regioselective synthesis of some novel phenylsulfones bearing isoprene units were accomplished by using the corresponding terpenoid compounds as the starting material through ene-chlorination and phenyl...The facile and regioselective synthesis of some novel phenylsulfones bearing isoprene units were accomplished by using the corresponding terpenoid compounds as the starting material through ene-chlorination and phenylsulfonyl group substritution steps. The yields are excellent and the experimental conditions are very mild.展开更多
基金support from the National Natural Science Foundation of China(Nos.22071007,22020102001,22335002)the National Key R&D Program of China(No.2022YFB3602802)+3 种基金Beijing Natural Science Foundation(No.Z220025)the National Facility for Protein Science in Shanghai,Shanghai Advanced Research Institute,CAS,for providing technical support in X-ray diffraction data collectionthe High-Performance Computing Platform of Peking University for supporting the computational workthe support of BMS Junior Fellow program。
文摘Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22001251,21922112,and 22225107)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)+1 种基金National Key R&D Program of China(No.2017YFA0700103)the Guizhou Provincial S&T Project(No.2018[4007]).
文摘Borylation of 1,3-enynes with bis(boronate)compounds often ends up with the formation of hydroborylated products,leaving the diborylation of 1,3-enynes for the formation of 1,4-diborylated allenes to be challenging.Herein,a copper-catalyzed chemo-,regio-,and stereo-selective diborylation of 1,3-enynes for the efficient construction of 1,4-diborylated allenes under base-free conditions was reported.A wide range of 1,3-enynes bearing various functional groups can participant in the reaction and afforded the corresponding 1,4-diborylated allenes in good to excellent yields,which was enabled by the protocol of Bpin to BF3K conversion.the borylcopper species was supposed to selectively attack the C-C triple bond of the 1,3-enynes.
基金supported by the National Key R&D Program of China(No.2018YFC0406304)the Central Public-Interest Scientific Institution Basal Research Fund(No.1610232019005)the Agricultural Science and Technology Innovation Program(No.ASTIPTRIC06)
文摘Permanganate has attracted much attention in wide range of chemistry and particularly in degradation of environmental pollutants.However,few studies have discussed the feature of regioselective reactivity of permanganate with specific moiety of the target compound.Herein,we studied the reaction between permanganate and tetracycline that is an emerging micropollutant with different species containing several electron-rich groups.The second-order rate constants increased from 6.0 to 9.0 and could be quantitatively modeled by considering the speciation of both reactants,yielding kTC0=11.7(mol/L)^-1 sec^-1,kTC-=35.7(mol/L)^-1 sec^-1,kTC2-=43.1(mol/L)^-1 sec^-1 for individual reaction channels.Degradation products were then identified as the hydroxylated and demethylated compounds.The result suggested a rate-limiting step of simple hydroxylation at the phenolic and/or alkene moieties,while the demethylation should be caused by the unavoidably formed manganese oxide via single electron oxidation.This is supported by the DFT calculation,indicating the primary oxidation of phenolic group of TC0 with activation barrier of 44.5 kcal/mol and of alkene group of TC-and TC2-with activation barriers of 44.0 and 43.4 kcal/mol,respectively.This is in agreement with the experimental results,implying the alternation of regioselectivity associated with the deprotonation process.The result was further supported by performing the Fukui function and electrostatic potential analysis,reflecting the more probable site and better electron donating tendency beneficial to the permanganate oxidation.
文摘Reaction of activated aromatics containing phenobs, naphthol, methoxynaphthalenes,anisole etc. with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding monobromination products with excellent yields.
基金supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.08KJD350001)program for New Century Excellent Talents by the Ministry of Education(No.NCET-09-0163)+1 种基金program for Outstanding Scientific and Technological Innovation Team of Jiangsu Higher Education(2009)Innovative Training Programs for Students in Jiangsu Higher Education Institutions(2009)
文摘Synthetic studies on the construction of 7-O-methylquercetin from quercetin in 36% yield in four steps is reported, this strategy relies on one hand on the selective protection of the catechol group with dichlorodiphenylmethane using dephenyl ether as a solvent, on the other hand, on the selective protection of the 3-hydroxyl group with benzyl bromide, these two different protecting groups can be removed under the same hydrogenation.
文摘The first three-component and regioselective synthesis of pyridazinones and phthalazinones from arenes,anhydrides and ArNHNH;in the presence of efficient recyclable heterogeneous catalyst,montmorillonite-KSF,in high yield and short reaction time is reported.
基金the financial support from the Research Council of Payame Noor University(PNU),Abhar-lran, and my colleague Ismail Hasani Asl
文摘An efficient triethylamine-catalyzed synthesis of 4-amino-3,5-dicyano-6-arylphthalates is described.A one-pot,simple pseudo four-component reaction between arylaldehydes,dialkyl acetylenedicarboxylates, and twice as much malononitrile gave 4-amino-3,5-dicyano-6-arylphthalates in good to excellent yields.
文摘The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discussed.
基金support of this study by the Payame Noor University(PNU)of Ilam
文摘In this study, 1-（1-alkylsulfonic）-3-methylimidazolium chloride as a new, green, and reusable Br？nsted acid catalyst was prepared. In this protocol, we used for the regioselective ring-opening reactions of various epoxiodes with sodium azide to afford the corresponding b-azido alcohols in excellent yields and short reaction time under mild and neutral reaction conditions. This method offers several advantages including excellent regioselectivity, clean reactions, simple work-up procedure, a recyclable catalyst,and use of an eco-friendly catalyst.
基金Financial support from the Research Council of University of Guilan is sincerely acknowledged
文摘An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times（3-4 min） and excellent yields（87-95%）.
基金This research was funded by The Talents Project for Harbin Science and Technology Innovation,grant number 2016RAXXJ006China Postdoctoral Science Foundation,grant number 2017M611341.
文摘Cellulose nanofibrils(CNFs)are promising sustainable materials that can be applied to nanocomposites,as well as medical and life-sciences devices.However,methods for the preparation of these important materials are energy intensive because heating and mechanical disintegration are required to produce cellulose fibers below 100 nm in size.In this study,CNFs were prepared through the multi-site regioselective oxidation of cellulose with 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)and periodate at room temperature(20–25°C),without any mechanical-disintegration treatment.Transmission electron microscopy(TEM)revealed that the CNFs had the average widths of 14.1,55.4,and 81.9 nm for three different treatments.Fourier-transform infrared spectroscopy revealed that carboxyl groups were created on the surfaces of the microfibrils,while X-ray diffraction studies showed that the cellulose I structure was maintained after oxidation,and that the cellulose nanofibril crystallinity index exceeded 70%.These results demonstrate that CNFs can be prepared by multi-site regioselective oxidation at room temperature in the absence of mechanical disintegration.In addition,a model was developed to calculate the total content of carboxylate and aldehyde groups of CNFs prepared by the TEMPO mediate oxidation,the periodate oxidation,and the multi-site regioselective oxidation methods based on the particle width determined by TEM.The calculated values of the model were in good agreement with the total content(experimental value)of carboxylate and aldehyde groups of CNFs prepared by the TEMPO-mediated oxidation and the multi-site regioselective oxidation methods.However,the model was not valid for CNFs prepared by the periodate oxidation method.
基金National Basic Research Program(973 Program,Grant No.2004CB518904).
文摘The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.
基金the NNSFC(No.20172027)the Natural Science Foundation of Tianjin(05YFJMJC00600)for financial support.
文摘A novel and efficient route of synthesizing 1, 2, 4-triazoline-5-ones is reported. The title compounds can be prepared in high yield and purity by the one-pot oxidation and cyclization of 1-acylthiosemicarbazides. The reaction is regioselective and stereoselective. The reaction condition is mild.
基金the National Natural Science Foundation of China(No.21276237)for financial support
文摘A concise and efficient approach was developed for the synthesis of pentacyclic compounds containing coumarin, pyrrole, indene in a regioselective manner in good yields via the reactions of N-substituted 4- aminocoumarin compounds and ninhydrin using microwave irradiation. No catalysts are required in our protocol.
文摘Di-O-acetyl sucrose was regioselective synthesized by using dibutyltin oxide in about 60% yield. The structure of acetyl derivative was elucidated by 1H NMR, 13C NMR, 2D-NMR and MS spectral data.
文摘Semi-synthesis of paclitaxel was achieved in four steps from 10-deacetylbaccatin HI （10-DAB HI）. The key steps are the regioselective protection at the hydroxyl group at C-7 of 10-DAB HI, using 1,1′-thiocarbonyldiimidazole as a selective reagent, and the deprotection of the protected paclitaxel with a mixture of p-toluenesulfonic acid and 0.1 mol/L aqueous hydrochloride.
文摘Regioselective decomposition of 11-substituted- 16α, 17α-methyleneazopregna- 1,4-dien- 3, 20-dione Ⅰ proceeded smoothly through thermal decomposition in the presence of BF3·Et2O or HClO4 with high yields. Ⅰ was converted to 11-substituted-16-methylpregna-1, 4, 16（17）-trien-3, 20-dione Ⅱ by the thermal decomposition, while with HClO4 ad a catalyst, 11-substituted-16α, 17α-methylenepregna-1, 4-dien-3, 20-dione Ⅲ was the main product. However, when BF3·Et2O was used as catalyst, a mixture of Ⅱ and Ⅲ（1 ： 3） was obtained.
基金the National Natural Science Foundation of China (Nos.21572051,21602057,21901071,and 21971061)Natural Science Foundation of Hunan Province (Nos.2020JJ5350 and 2020JJ5347)+1 种基金Scientific Research Fund of Hunan ProvincialEducation Department (Nos.18A002,19B359 and 17C1137)Science and Technology Planning Project of Hunan Province (No. 2018TP1017) for financial support。
文摘A simultaneous C2-H arylation and C8-H alkylation of naphthalene ring has been achieved by palladiumcatalyzed cascade reaction of N-(2-halophenyl)-2-(naphthalen-1-yl)acrylamides with aryl iodides,which provides an efficient method for synthesizing various aryl-substituted spirocyclic oxindoles.The protocol enables three C-C bonds formation via an intramolecular Heck reaction and sequentially regioselective C-H bond activation.
基金financially supported by the National Natural Science Foundation of China(Nos.21134002 and 21174023)Program for Changjiang Scholars and Innovative Research Teams in University(No.IRT13008)the Chang Jiang Scholars Program(No.T2011056)from the Ministry of Education of China
文摘This report presents a detailed density functional theory （DFT） study on the difference in regioselectivity for the copolymerization reactions of styrene oxide versus propylene oxide with CO2 utilizing binary （salen）cobalt（III） catalyst systems. This study focuses on the discrepancy of regioselective ring-opening of two terminal epoxides during the copolymerization with CO2. It was found that the nucleophilic ring-opening of styrene oxide occurred predominantly at the methine C a--O bond due to the election delocalization of phenyl group to stabilize the transition state for the methine C--O bond cleavage.
文摘The facile and regioselective synthesis of some novel phenylsulfones bearing isoprene units were accomplished by using the corresponding terpenoid compounds as the starting material through ene-chlorination and phenylsulfonyl group substritution steps. The yields are excellent and the experimental conditions are very mild.
