Practical Asymmetric Synthesis: New Protocols, Ligands and Other Control Elements

T. V. (Babu) RajanBabu

Professor

The Ohio State University

Department of Chemistry, 100 W. 18^th Ave.

Columbus, OH 43210, USA

In this era of heightened environmental awareness and ever-increasing demand for higher efficiency from chemical processes, one of the major challenges facing organic synthesis is the utilization of abundantly available carbon sources for fine chemical synthesis. The dual problems of activation of thermodynamically stable precursors and their stereoselective incorporation pose new challenges, solutions of which may have broader implications in asymmetric catalysis. In this context, we have discovered new protocols for a nearly quantitative and highly selective codimerization of ethylene or propylene, and various functionalized vinylarenes and strained olefins. This talk will deal with the development of various strategies for stereochemical control in an enantioselective version of this reaction. These include design and synthesis of new ligands and applications of the ‘hemi-labile ligand concept’. The products of this reaction are potentially useful for the synthesis of widely used antiinflammatory 2-arylpropionic acids.

Examples of the use of various control elements such as ligand electronic and steric effects, and effects of counterions to improve the efficiency and selectivity of other key C-C and C-H bond-forming reactions will also be illustrated.