An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality  

作　　者：Qi Liu Xue-Dong Li Liang Cheng Li Liu 

机构地区：[1]Beijing National Laboratory for Molecular Sciences(BNLMS),CAS Key Laboratory of Molecular Recognition and Function,CAS Research/Education Center for Excellence in Molecular Sciences,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Chemistry》2024年第9期2998-3003,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(22022704,21977097,22271291),Chinese Academy of Sciences。

摘　　要：The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral compounds.However,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination process.In this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent enantioselectivity.In addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis acid.This methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关 键 词：br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion 

分 类 号：O621.251[理学—有机化学]