Nanoporous Gold-Catalyzed Diboration of Methylenecyclopropanes via a Distal Bond Cleavage

We have demonstrated that nanoporous gold (AuNPore) is an efficient catalyst to promote the selective diboration of methylenecyclopropanes (MCPs) in a heterogeneous manner. Notably, the diboration takes place via a regioselective cleavage of the distal bond of the cyclopropane ring exclusively by AuNPore without using any additives. The experimental results and computational studies of the mechanism indicate that the present diboration proceeds through the formation of a relatively stable trimethylenemethane intermediate on the AuNPore surface with increased negative charges on trimethylene carbons, giving rise to the subsequent diboration selectively.