Dual Photoredox and Titanium Catalyzed Regioselective Allenylation of Aldehydes via Reductive Radical-Polar Crossover  

作　　者：Zulin Xiao Wenzhe Shang Tao Huang Lei He Jingyao Li Shen Luo Xiaoxia He Xiang Li Fusheng Li 

机构地区：[1]School of Chemistry and Chemical Engineering,University of South China,Hengyang,Hunan,421001 China [2]Dalian University of Technology,School of Chemistry,Dalian,Liaoning,116024 China

出　　处：《Chinese Journal of Chemistry》2025年第3期275-280,共6页中国化学(英文版)

基　　金：supported by the Fundamental Research Funds for the University of South China(No.220XQD08).

摘　　要：The direct reductive coupling of carbonyl compounds with propargyl halides is a powerful and reliable tool in the synthesis ofα-allenols.However,stoichiometric metal reductants,harsh reaction conditions and a variety of additional additives are required in the traditional strategies.Additionally,the reactivity and regioselectivity control remains an elusive challenge.Herein,we developed the Ti-catalyzed regioselective reductive coupling of readily available aldehydes and racemic propargyl bromides to rapidly access a wide range ofα-allenols.This method proceed efficiently in a reductive radical-polar crossover manner featuring mild conditions,excellent regioselectivity control,broad substrate scope,and eco-friendliness.Preliminary mechanistic studies support the radical-involved catalytic cycle.And the DFT calculations demonstrate that the regioselectivity is determined by the Zimmerman-Traxler-type transition states.

关 键 词：Photoredox catalysis Titanium catalysis α-Allenols Regioselectivity Reductive radical-polar crossover C-C coupling 

分 类 号：O62[理学—有机化学]