Chiral Phenol-2NO Ligand Cooperation with Achiral Organic Base in the Zn(II)-Catalyzed Asymmetric Alkylation Reaction of Indoles  

作　　者：Ke-Lan Xu Yu-Heng Wang Xi-Rui Wang Pan Hu Bo-Wen Pan Wen-Jing Zhang Zi-Yue Chen Ying Zhou Xiong-Li Liu 

机构地区：[1]National&Local Joint Engineering Research Center for the Exploitation of Homology Resources of Southwest Medicine and Food,Guizhou University,Guiyang,Guizhou 550025,China [2]College of Pharmaceutical Sciences,Guizhou University of Traditional Chinese Medicine,Guiyang,Guizhou 550025,China [3]Green Catalysis Center,and College of Chemistry,Zhengzhou University,Zhengzhou,Henan 450001,China

出　　处：《Chinese Journal of Chemistry》2024年第13期1474-1480,共7页中国化学（英文版）

基　　金：We thank financial support from NSFC(22061006);Guizhou Provincial Program(GCC[2023]047,GCC[2023]078,ZK[2023]043,ZK[2022]144,ZK[2022]480).

摘　　要：The privileged C_(2)-symmetric rigid phenol-type ligand is more attractive but challenging in asymmetric catalysis.Herein,we designed and synthesized a class of rigid-featured chiral tridentate Phenol-2NO ligands,that incorporate the advantages of both the phenol skeleton and pyrroloimidazolone-based N-oxide moiety,from readily available L-prolinamides in operationally simple two steps and up to 44%overall yield.More importantly,using an achiral quinoline derivative as an additive,the newly developed Phenol-2NO ligand could serve as the anioic ligand upon deprotonative activation to coordinate to Zn(II)to form a highly enantioselective catalyst for the asymmetric Michael-type Friedel-Crafts alkylation reaction of indoles with 2,3-dioxopyrrolidines.Excellent yields(up to 90%)and high enantioselectivities(up to 99%ee)are obtained for a wide range of substrates under mild conditions.Experiments and DFT calculations revealed the reaction mechanism and the origins of the enantioselectivity.This also represented the first activation of phenol-type ligand/metal complex by an achiral organic base as the additive in asymmetric catalysis.

关 键 词：Phenol-2NO C_(2)-Symmetric Rigid-featured Tridentate ligand Asymmetric catalysis ALKYLATION Synthesis design HETEROCYCLES 

分 类 号：O62[理学—有机化学]