Cross-Coupling of Diarylborinic Acids and Anhydrides with Arylhalides Catalyzed by a Phosphite/N-Heterocyclic Carbene Co-supported Palladium Catalyst System
作者:Xiaofeng Chen、Haihua Ke、Yao Chen、Changwei Guan、Gang Zou
DOI:10.1021/jo301335x
日期:2012.9.7
A highly efficient cross-coupling of diarylborinic acids and anhydrides with aryl chlorides and bromides has been effected by using a palladium catalyst system co-supported by a strong σ-donor N-heterocyclic carbene (NHC), N,N′-bis(2,6-diisopropylphenyl) imidazol-2-ylidene, and a strong π-acceptor phosphite, triphenylphosphite, in tert-BuOH in the present of K3PO4·3H2O. Unsymmetrical biaryls with a
A高效交叉偶联的二芳基羧酸和芳基氯化物和溴化物酸酐已经通过使用钯催化剂体系共负载通过强σ供体的N-杂环卡宾(NHC),实现Ñ,Ñ ' -双(2- K 3 PO 4 ·3H 2的存在下,在叔-BuOH中形成亚胺基-6-亚甲基二唑-2-亚胺基,亚磷酸三苯酯和强苯基受体亚磷酸三苯酯O.在温和的条件下,分别使用低至0.01、0.2-0.5和1 mol%的钯基芳基溴以及活化和失活的芳基氯化物,分别以良好或优异的收率获得具有各种官能团的不对称联芳基。已提出在Pd / NHC / P(OPh)3催化体系中σ供体NHC和π受体亚磷酸酯之间的配体协同作用可导致交叉偶联中芳基氯化物的高效率。因此,已经开发了一种可扩展且经济的方法,用于由Pd / NHC / P(OPh)3催化的二(4-甲基苯基)硼酸与2-氯苄腈的交叉偶联反应来合成Sartan联苯。