Efficient and modular syntheses of new chiral nonracemic C2-symmetric 2,2'-bipyridyl and pyridylphosphine ligands: Applications in catalytic asymmetric synthesis

ORGN 775

Michael P. A. Lyle, mlyle@sfu.ca and Peter D. Wilson, pwilson@sfu.ca. Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
Of the many different types of ligands that have been developed for catalytic asymmetric synthesis, chiral nonracemic pyridine containing ligands have received considerable recent attention. Here we present the syntheses and evaluation of two new classes of chiral 2,2'-bipyridyl ligands 1 and 3a-c (R = Me, i-Pr and Ph) as well as a related class of chiral P,N-ligands 2a-c (R = Me, i-Pr and Ph). Very high stereoselectivities have been observed with ligand 1 in the copper(I)-catalyzed asymmetric cyclopropanation reaction of alkenes and the copper(II)-catalyzed asymmetric Friedel-Crafts reactions of substituted indoles. The P,N-ligands 2a-c have been shown to be effective chiral directors in the palladium-catalyzed asymmetric allylic alkylation reaction and a detailed mechanistic study has been conducted. Crystallographic characterization of complexes for each ligand type will also be presented.

 

Asymmetric Reactions, Molecular Recognition, Self Assembly, Bioorganic Chemistry, Process R&D
8:00 PM-10:00 PM, Wednesday, 16 March 2005 Convention Center -- Hall D, Poster

Division of Organic Chemistry

The 229th ACS National Meeting, in San Diego, CA, March 13-17, 2005