Enantio- and Diastereoselective Suzuki-Miyaura Coupling with Racemic Bicycles

Abstract

Herein we describe a rhodium-catalyzed enantio- and diastereoselective Suzuki-Miyaura cross-coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl-, heteroaryl- and vinyl boronic acids and gives access to functionalized bicyclic cyclopentenes which can be converted to other five-membered ring scaffolds with up to five contiguous stereocenters. Preliminary mechanistic studies suggest that these reactions occur with overall retention of the relative stereochemistry and is enantioconvergent for pseudo-symmetric allylic chloride starting materials. In addition, a bicyclic allylic chloride starting material without pseudo-symmetry undergoes a highly enantioselective regiodivergent reaction.