One-step highly selective borylation/Suzuki cross-coupling of two distinct aryl bromides in pure water

Abstract

A Na₂PdCl₄-catalysed B₂(OH)₄-mediated direct cross-coupling of two distinct aryl bromides in pure water is described. This one-step borylation/Suzuki method exhibits an outstanding cross-coupling selectivity and no tendency to produce homocoupling products, therefore leading to biaryls and heterobiaryls in moderate to good yields. Moreover, the reaction has high regio-selectivity and can be scaled-up. Using such a simple, economical and practical protocol, the unsymmetrical diarylation of 3,5-dibromopryidine is achieved.