Direct C(sp3)-H functionalization of N-unprotected aliphatic amines represents one of the most efficient and straightforward strategies for amine synthesis.Despite some recent progress in this field,the NH2-directed y...Direct C(sp3)-H functionalization of N-unprotected aliphatic amines represents one of the most efficient and straightforward strategies for amine synthesis.Despite some recent progress in this field,the NH2-directed y-C(sp3)-H arylation of primary aliphatic amines exceptα-amino esters remained an unmet challenge.In this report,we established a simple and efficient method for site-selective C(sp3)-H arylation of primary aliphatic amines by aryl iodides.In the presence of only 5 mol%Pd(OAc)2,a wide range of aliphatic amines including O-benzyl and O-silyl amino alcohols were arylated at y-orδ-positions by aryl iodides containing a broad scope of functional groups.The synthetic application of this method had also been demonstrated by large-scale synthesis,the synthesis of a fingolimod analogue,and the conjugation with natural D-menthol and fluorescent 1,8-naphthalimide.展开更多
Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free co...Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.展开更多
Mediated by visible light-induced photoredox catalysis and free of other catalysts, a new and efficient synthesis of methylene-bridged bis-l,3-dicarbonyl derivatives has been developed. A variety of N-methyl tertiarya...Mediated by visible light-induced photoredox catalysis and free of other catalysts, a new and efficient synthesis of methylene-bridged bis-l,3-dicarbonyl derivatives has been developed. A variety of N-methyl tertiaryamines and 1,3-dicarbonyl compounds were investigated in this reaction.展开更多
Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from al...Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp^(2))-H fluorination is reported.This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer.A variety of functional groups were well tolerated for this transformation.This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.展开更多
Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylati...Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylation reaction is operationally simple and shows high functional group tolerance and broad substrate scope.Preliminary mechanistic studies suggest that the reaction proceeds through S_(N)2-based radical-generation strategy.展开更多
基金the National Natural Science Foundation of China(No.21502006)Beijing National Laboratory for Molecular Sciences and Beijing Institute of Technology(BIT)for financial support。
文摘Direct C(sp3)-H functionalization of N-unprotected aliphatic amines represents one of the most efficient and straightforward strategies for amine synthesis.Despite some recent progress in this field,the NH2-directed y-C(sp3)-H arylation of primary aliphatic amines exceptα-amino esters remained an unmet challenge.In this report,we established a simple and efficient method for site-selective C(sp3)-H arylation of primary aliphatic amines by aryl iodides.In the presence of only 5 mol%Pd(OAc)2,a wide range of aliphatic amines including O-benzyl and O-silyl amino alcohols were arylated at y-orδ-positions by aryl iodides containing a broad scope of functional groups.The synthetic application of this method had also been demonstrated by large-scale synthesis,the synthesis of a fingolimod analogue,and the conjugation with natural D-menthol and fluorescent 1,8-naphthalimide.
文摘Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.
基金Zhejiang Provincial Natural Science Foundation of China(No.LY12B02017)
文摘Mediated by visible light-induced photoredox catalysis and free of other catalysts, a new and efficient synthesis of methylene-bridged bis-l,3-dicarbonyl derivatives has been developed. A variety of N-methyl tertiaryamines and 1,3-dicarbonyl compounds were investigated in this reaction.
基金We thank the NSFC(No.21971093)the International Joint Research Centre for Green Catalysis and Synthesis(No.2016B01017)the 111 projects for support of our research.We also thank the Canada Research Chair(Tier I)foundation,the E.B.Eddy Endowment Fund,the Canada Foundation for Innovation,and the Natural Sciences and Engineering Research Council of Canada to Chao-Jun Li.
文摘Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds,especially peptides.Herein,a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp^(2))-H fluorination is reported.This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer.A variety of functional groups were well tolerated for this transformation.This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.
基金Financial support from the National Natural Science Foundation of China(Nos.21772046,2193103,22001038)are gratefully acknowledged.
文摘Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylation reaction is operationally simple and shows high functional group tolerance and broad substrate scope.Preliminary mechanistic studies suggest that the reaction proceeds through S_(N)2-based radical-generation strategy.
