Palladium catalyzed enantioselective rearrangement of allylic imidates to allylic amides

Abstract

Recent progress in developing asymmetric Pd(II) catalysts for the [3,3]-sigmatropic rearrangement of allylic imidates to form enantioenriched allylic amides is reviewed. The best catalysts developed to date generate allylic amides in >90% enantiomeric excess (ee) from some allylic imidate substrates. The most recent catalysts developed in our laboratories are based on cyclopalladated ferrocenes having elements of planar chirality. A mechanistic proposal that enantioselection in Pd(II)-catalyzed allylic imidate rearrangements might derive from axial approach of the alkene to the chiral Pd(II) catalyst has guided our design of improved ligands.