The enantioselective separation of racemate,particularly those containing C(sp^(3))-H bonds knowns for their high bond dissociation energies and significant polarity,presents a significant challenge in pharmaceutical ...The enantioselective separation of racemate,particularly those containing C(sp^(3))-H bonds knowns for their high bond dissociation energies and significant polarity,presents a significant challenge in pharmaceutical synthesis.Recent advances have witnessed the fusion of photocatalysis with hydrogen atom transfer(HAT)methodologies,marking a notable trend in synthesis of chiral molecules.This technique uses the excitation of a catalyst to activate substrates,enabling the selective isomerization of chiral centers containing C(sp^(3))configurations.This process distinctively facilitates the direct activation of the C(sp^(3))-H bond in targeted reagents.This review systematically discusses the photocatalytic isomerization of various chiral molecule featuring C(sp^(3))-H centers,capable of undergoing deracemization through two primary HAT mechanisms:direct and indirect pathways.From the perspective of synthetic organic chemistry,this field has progressed towards the development of isomerization strategies for molecules that incorporate an activating group at theα-position adjacent to the C(sp^(3))chiral center.Moreover,it covers methodologies applicable to molecules characterized by specific C-C and C-S bond configurations.The integration of photocatalysis with HAT technology thus provides valuable strategies for the synthesis of enantiopure compounds with enhanced selectivity and efficiency.展开更多
Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly...Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly hindered by the poor surface kinetics of the hydrogen evolution reaction(HER)and severe charge recombination.Herein,we demonstrate that the electrostatic self-assembly of MoS_(2) colloids on CdS nanosheets(MoS_(2)/CdS)can efficiently capture photogenerated electrons to drive H^(+) reduction,owing to their intrinsic excellent catalytic ability for HER and their strong electron-sink effect for charge separation.This,in turn,facilitates the migration of photogenerated holes from the bulk to the surface,enabling more holes to initiate the oxidative cleavage of C–H bonds in benzyl derivatives,such as cumene.More importantly,MoS_(2) colloids,with Mo atoms sandwiched between two sulfur layers,exhibit much lower interaction with produced·C(CH_(3))_(2) Ph radicals compared to conventional HER cocatalysts,such as noble or transition metal co-catalysts.This facilitates the departure of the·C(CH_(3))_(2) Ph radicals for C(sp^(3))–C(sp^(3))homocoupling reactions,thus enhancing selectivity toward bicummyl.This work presents an efficient,green,and cost-effective strategy for the dehydrogenative homocoupling of benzyl derivatives to construct C(sp^(3))–C(sp^(3))bonds under mild conditions.展开更多
基金the National Natural Science Foundation of China(No.22072020)the Science Foundation of the Fujian Province(Nos.2022HZ027004,2022L3082,2021L3003,and 2019 J01203).
文摘The enantioselective separation of racemate,particularly those containing C(sp^(3))-H bonds knowns for their high bond dissociation energies and significant polarity,presents a significant challenge in pharmaceutical synthesis.Recent advances have witnessed the fusion of photocatalysis with hydrogen atom transfer(HAT)methodologies,marking a notable trend in synthesis of chiral molecules.This technique uses the excitation of a catalyst to activate substrates,enabling the selective isomerization of chiral centers containing C(sp^(3))configurations.This process distinctively facilitates the direct activation of the C(sp^(3))-H bond in targeted reagents.This review systematically discusses the photocatalytic isomerization of various chiral molecule featuring C(sp^(3))-H centers,capable of undergoing deracemization through two primary HAT mechanisms:direct and indirect pathways.From the perspective of synthetic organic chemistry,this field has progressed towards the development of isomerization strategies for molecules that incorporate an activating group at theα-position adjacent to the C(sp^(3))chiral center.Moreover,it covers methodologies applicable to molecules characterized by specific C-C and C-S bond configurations.The integration of photocatalysis with HAT technology thus provides valuable strategies for the synthesis of enantiopure compounds with enhanced selectivity and efficiency.
基金financial support from the National Natural Science Foundation of China(NSFC,Nos.22372036,U24A20567,and 21972022)Natural Science Foundation of Fujian Province(No.2024HZ027004)+4 种基金Natural Science Foundation of Jiangxi Province(Nos.20252BAC240721 and 20232BAB213014)the 111 Project(No.D16008)Program of Jiangxi Academy of Sciences(No.2024TJPT003)Jiangxi Carbon Neutralization Research Center(No.2023YSTZX01)Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(No.SKLPEE-KF202303),Fuzhou University.
文摘Photocatalytic dehydrogenative homocoupling of benzyl derivatives is a green and sustainable strategy for the direct construction of C(sp^(3))–C(sp^(3))bonds.However,the efficiency of these reactions is significantly hindered by the poor surface kinetics of the hydrogen evolution reaction(HER)and severe charge recombination.Herein,we demonstrate that the electrostatic self-assembly of MoS_(2) colloids on CdS nanosheets(MoS_(2)/CdS)can efficiently capture photogenerated electrons to drive H^(+) reduction,owing to their intrinsic excellent catalytic ability for HER and their strong electron-sink effect for charge separation.This,in turn,facilitates the migration of photogenerated holes from the bulk to the surface,enabling more holes to initiate the oxidative cleavage of C–H bonds in benzyl derivatives,such as cumene.More importantly,MoS_(2) colloids,with Mo atoms sandwiched between two sulfur layers,exhibit much lower interaction with produced·C(CH_(3))_(2) Ph radicals compared to conventional HER cocatalysts,such as noble or transition metal co-catalysts.This facilitates the departure of the·C(CH_(3))_(2) Ph radicals for C(sp^(3))–C(sp^(3))homocoupling reactions,thus enhancing selectivity toward bicummyl.This work presents an efficient,green,and cost-effective strategy for the dehydrogenative homocoupling of benzyl derivatives to construct C(sp^(3))–C(sp^(3))bonds under mild conditions.
