The Vinylogous Wolff Rearrangement Catalyzed with RhII Complexes

Abstract

Decomposition of ?,?-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 CuII catalysts. Chiral catalysts such as tetrakis [methyl (S)-5-oxopyrrolidine-2-carboxylate]dirhodium(II) and CuI 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.