A rhodium-catalyzed desymmetrization reaction for enantioselective methyl C-H arylation is achieved by utilizing an in situ arylating reagent via nucleophilic cyclization of o-aminoaryl alkyne.The reaction results in ...A rhodium-catalyzed desymmetrization reaction for enantioselective methyl C-H arylation is achieved by utilizing an in situ arylating reagent via nucleophilic cyclization of o-aminoaryl alkyne.The reaction results in chiral indoles containing all-carbon quaternary stereocenters under atmospheric conditions,with a wide range of substrates exhibiting good enantioselectivity(44 examples).Mechnism and DFT studies show that the stereocontrol is reasonably achieved through the collaborative control of a large silicon substituted chiral ligand and C-H···π,LP···πinteractions between aryl rings of the carboxylate group and the substrate.Control experiments demonstrate that Rh-aryl bond formation via in situ nucleophilic cyclization is more critical for reaction efficiency than via C-H activation of the nucleophilic cyclization byproduct.展开更多
Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was devel...Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).展开更多
Herein,a novel copper metal-organic framework(MOF),[Cu_(2)(CPTPTA)(H_(2)O)]·CH_(3)NH_(3)^(+)·4H_(2)O·7NMF(1)(H_(5)CPTPTA=5’-(4-carboxyphenyl)-[1,1’:3’,1’’-terphenyl]-3,3’’,5,5’’-tetracarboxylic...Herein,a novel copper metal-organic framework(MOF),[Cu_(2)(CPTPTA)(H_(2)O)]·CH_(3)NH_(3)^(+)·4H_(2)O·7NMF(1)(H_(5)CPTPTA=5’-(4-carboxyphenyl)-[1,1’:3’,1’’-terphenyl]-3,3’’,5,5’’-tetracarboxylic acid,NMF=N-methylformamide),has been successfully synthesized via solvothermal reaction.By applying a linker desymmetrization strategy,compound 1 was constructed by a reduced-symmetry ligand CPTPTA^(5-),leading to three types of channels with various functional sites.Meanwhile,the functional sites promoted the adsorption of CO_(2),the uptakes being 123.2(2)and 66.8(2)cm^(3) g^(-1) at 273 and 298 K,respectively.Furthermore,the smaller channel exists as two kinds of active sites:Lewis acid sites(LASs)and Bronsted acid sites(BASs);whereas the larger one only exists as LASs.The synergistic catalysis of LASs and BASs makes compound 1 exhibit excellent CO_(2) cycloaddition efficiency towards propylene oxide,and the yield can reach 97%.Overall,such a linker desymmetrization strategy can afford an effective approach to synthesize novel functional MOF materials.展开更多
Highly efficient synthesis of the entitled compound was achieved from a readily availablemyo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethylketal to give two diastereomers. The ...Highly efficient synthesis of the entitled compound was achieved from a readily availablemyo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethylketal to give two diastereomers. The two diastereomers could be used to synthesize the samecompound by changing the orders to introduce the protective groups.展开更多
基金financial support for this work from the National Key R&D Program of China(No.2021YFC0864700)the National Natural Science Foundation of China(Nos.21801066,U1804283 and 82130103)+2 种基金the Central Plains Scholars and Scientists Studio Fund(No.2018002)the project funded by the Natural Science Foundation of Henan(Nos.222300420056,222300420204)the China Postdoctoral Science Foundation(Nos.2020M682307,2021T140183)。
文摘A rhodium-catalyzed desymmetrization reaction for enantioselective methyl C-H arylation is achieved by utilizing an in situ arylating reagent via nucleophilic cyclization of o-aminoaryl alkyne.The reaction results in chiral indoles containing all-carbon quaternary stereocenters under atmospheric conditions,with a wide range of substrates exhibiting good enantioselectivity(44 examples).Mechnism and DFT studies show that the stereocontrol is reasonably achieved through the collaborative control of a large silicon substituted chiral ligand and C-H···π,LP···πinteractions between aryl rings of the carboxylate group and the substrate.Control experiments demonstrate that Rh-aryl bond formation via in situ nucleophilic cyclization is more critical for reaction efficiency than via C-H activation of the nucleophilic cyclization byproduct.
基金Project supported by the Natural Science Foundation of Henan Province(Nos.232300421234,252300421726)the Leading Talents in Scientific and Technological Innovation in Shangqiu(No.SQRC202212004)the Program of Ecological Environmental Protection in the Area of Old Course of Yellow River of Shangqiu Normal University。
文摘Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).
基金supported by the National Natural Science Foundation of China(no.21771078 and 21621001)the 111 Project(B17020).
文摘Herein,a novel copper metal-organic framework(MOF),[Cu_(2)(CPTPTA)(H_(2)O)]·CH_(3)NH_(3)^(+)·4H_(2)O·7NMF(1)(H_(5)CPTPTA=5’-(4-carboxyphenyl)-[1,1’:3’,1’’-terphenyl]-3,3’’,5,5’’-tetracarboxylic acid,NMF=N-methylformamide),has been successfully synthesized via solvothermal reaction.By applying a linker desymmetrization strategy,compound 1 was constructed by a reduced-symmetry ligand CPTPTA^(5-),leading to three types of channels with various functional sites.Meanwhile,the functional sites promoted the adsorption of CO_(2),the uptakes being 123.2(2)and 66.8(2)cm^(3) g^(-1) at 273 and 298 K,respectively.Furthermore,the smaller channel exists as two kinds of active sites:Lewis acid sites(LASs)and Bronsted acid sites(BASs);whereas the larger one only exists as LASs.The synergistic catalysis of LASs and BASs makes compound 1 exhibit excellent CO_(2) cycloaddition efficiency towards propylene oxide,and the yield can reach 97%.Overall,such a linker desymmetrization strategy can afford an effective approach to synthesize novel functional MOF materials.
文摘Highly efficient synthesis of the entitled compound was achieved from a readily availablemyo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethylketal to give two diastereomers. The two diastereomers could be used to synthesize the samecompound by changing the orders to introduce the protective groups.
