Chiral ligands with pyridine donors in transition metal catalyzed enantioselective cyclopropanation and hydrosilylation reactions

Copper(I) and rhodium(I) complexes prepared in situ from [Cu(OTf)(C6H6)(0.5)] and [Rh(cod)Cl](2) with a range of chiral 2,2'-bipyridines, 5,6-dihydro-1,10-phenanthrolines, 1,10-phenanthrolines and 2,2':6',2 -terpyridines were assessed as chiral catalysts for the enantioselective cyclopropanation of styrene with diazoacetates and for the hydrosilylation of acetophenone with diphenylsilane. Enantioselectivities up to 68% in the cyclopropanation and up to 32% in the hydrosilylation were obtained. (C) 2000 Published by Elsevier Science Ltd.