Rhodium(iii)-catalyzed synthesis of phthalides by cascade addition and cyclization of benzimidates with aldehydes

Abstract

We herein report the Rh(III)-catalyzed C–H bond activation and addition of benzimidates to aldehydes to afford biologically important phthalides in a single step. The imidate is a novel and unexplored directing group that not only enables C–H bond activation and addition to aldehydes, but also serves to capture the reversibly formed alcohol intermediate. The reaction shows broad scope with a high level of functional group compatibility and is applicable to both aromatic and aliphatic aldehydes.