Alkynes are versatile synthons in organic synthesis,as well as important structural moieties in bioactive molecules.Recently,transition metal-catalyzed hydroalkynylation of alkenes has been developed with reactive alk...Alkynes are versatile synthons in organic synthesis,as well as important structural moieties in bioactive molecules.Recently,transition metal-catalyzed hydroalkynylation of alkenes has been developed with reactive alkenes and alkenes bearing directing groups.However,the regioselective hydroalkynylation of simple alkenes is still challenging.Herein,we have developed a palladium-catalyzed Markovnikov hydroalkynylation of unactivated terminal alkenes,which provides an efficient approach for the synthesis of branched alkynyl compounds under mild conditions.This reaction features excellent functional group tolerance,good reaction yields and excellent regioselectivity.Moreover,the asymmetric hydroalkynylation reaction has also been achieved with moderate enantioselectivity by introducing a sterically bulky chiral Pyox ligand.展开更多
Summary of main observation and conclusion An eficient palladium-atalyzed regioselective 5 exo aminotrifluoromethoxylation of alkenes has been established herein,which provides practical route towards the synthesis of...Summary of main observation and conclusion An eficient palladium-atalyzed regioselective 5 exo aminotrifluoromethoxylation of alkenes has been established herein,which provides practical route towards the synthesis of OCF g-containing prrolidines.tert-Butyloxycarbonyl(Boc)as an amino pro-tecting group plays a signifiant role in both the chemo-and regloselectivities.In addition,preliminary mechanistic studies reveal that the amino protect-ing group of substrates and the counter anion of palladium catalyst play critical roles in reaction efficiency presumably due to an isomerization of alkyl-Pd(Ⅱ)intermediates.Moreover,the asymmetric 5-exo aminrifluoromethoxylation reaction has also been achieved by introducing a serelallyl bulky pyri-dinyl-oxazoline ligand.展开更多
基金the National Key R&D Program of China(No.2021YFA1500100)the National Nature Science Foundation of China(Nos.22101295,21971255,91956202,92256301 and 21821002)+1 种基金the Science and Technology Commission of Shanghai Municipality(Nos.20JC1417000 and 21520780100)the Youth Innovation Promotion Association,CAS(Y2022074).
文摘Alkynes are versatile synthons in organic synthesis,as well as important structural moieties in bioactive molecules.Recently,transition metal-catalyzed hydroalkynylation of alkenes has been developed with reactive alkenes and alkenes bearing directing groups.However,the regioselective hydroalkynylation of simple alkenes is still challenging.Herein,we have developed a palladium-catalyzed Markovnikov hydroalkynylation of unactivated terminal alkenes,which provides an efficient approach for the synthesis of branched alkynyl compounds under mild conditions.This reaction features excellent functional group tolerance,good reaction yields and excellent regioselectivity.Moreover,the asymmetric hydroalkynylation reaction has also been achieved with moderate enantioselectivity by introducing a sterically bulky chiral Pyox ligand.
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21532009,21761142010,21971255,21728201 and 21790330)the Science and Technology Commission of Shanghai Municipality(Nos.17XD1404500,170A1405200 and 17JC1401200)+1 种基金the strategic Priority Re-search Program(No.XDB2000000)the Key Research Pro-gram of Frontier Science(QYZDISSW-SLH055)of the Chinese Academy of Sciences.
文摘Summary of main observation and conclusion An eficient palladium-atalyzed regioselective 5 exo aminotrifluoromethoxylation of alkenes has been established herein,which provides practical route towards the synthesis of OCF g-containing prrolidines.tert-Butyloxycarbonyl(Boc)as an amino pro-tecting group plays a signifiant role in both the chemo-and regloselectivities.In addition,preliminary mechanistic studies reveal that the amino protect-ing group of substrates and the counter anion of palladium catalyst play critical roles in reaction efficiency presumably due to an isomerization of alkyl-Pd(Ⅱ)intermediates.Moreover,the asymmetric 5-exo aminrifluoromethoxylation reaction has also been achieved by introducing a serelallyl bulky pyri-dinyl-oxazoline ligand.
