Catalytic asymmetric hydrometallation of cyclobutenes with salicylaldehydes

Abstract

Chiral, substituted cyclobutanes are common motifs in bioactive compounds and intermediates in organic synthesis but few asymmetric routes for their synthesis are known. Herein we report the Rh-catalyzed asymmetric hydrometallation of a range ofmeso-cyclobutenes with salicylaldehydes. Theortho-phenolic group promotes hydroacylation and can be used as a handle for subsequent transformations. The reaction proceedsviaasymmetric hydrometallation of the weakly activated cyclobutene, followed by a C-C bond forming reductive elimination. A prochiral, spirocyclic cyclobutene undergoes a highly regioselective hydroacylation. This report will likely inspire the development of other asymmetric addition reactions to cyclobutenesviahydrometallation pathways.