Uttam K Tambar
The University of Texas Southwestern Medical Center at Dallas, USA
Title: Allylic functionalization of unactivated hydrocarbons
Biography
Biography: Uttam K Tambar
Abstract
We have been exploring the selective functionalization of unactivated hydrocarbons. We have developed a catalytic enantioselective allylic amination of unactivated olefins via a [2,3]-rearrangement (Scheme 1). In this method, a diimido-sulfur reagent serves as the source of nitrogen, and it reacts selectively with terminal olefins through a hetero-ene reaction. The resulting zwitterionic ene adduct undergoes a Pd-catalyzed enantioselective [2,3]-rearrangement to generate chiral amines in high enantiomeric excess. Our approach is conceptually distinct from other enantioselective allylic amination strategies. The synthetic utility of our process is being explored by converting simple and inexpensive terminal olefins into functional materials, such as the pharmaceutical drugs Vigabatrin and Januvia. Based on this chemistry, we have also developed a copper-catalyzed allylic alkylation of unactivated olefins and dienes (Schemes 2 and 3). This represents a general method for functionalizing unactivated hydrocarbons with aromatic, aliphatic, and vinyl Grignard reagents. Our recent discoveries represent a conceptual framework for the generalized functionalization of unactivated olefins.