The Vinylogous Wolff Rearrangement Catalyzed with RhII Complexes

Abstract

Decomposition of β,γ-unsaturated diazoketones has been investigated in the presence of Rh₂(OAc)₄ catalyst. These reactions produce exclusively the products of the vinylogous Wolff rearrangement with higher yields than Cu^II catalysts. Chiral catalysts such as tetrakis [methyl (S)-5-oxopyrrolidine-2-carboxylate]dirhodium(II) and Cu^I bis(oxazoline) complexes, which are effective catalysts for the inter and/or intramolecular cyclopropanations reactions, catalyze the vinylogous Wolff rearrangement to produce the expected products with low levels of enantioselectivity.