Kinetic and computational analysis of the palladium(II)-catalyzed asymmetric allylic trichloroacetimidate rearrangement: development of a model for enantioselectivity.
The asymmetric rearrangement of allylic trichloroacetimidates catalyzed by palladium(II) complexes of the COP family is a powerful method for the preparation of enantioenriched chiral allylic amines from prochiral allylic alcohols. A detailed kinetic analysis of this reaction was performed to elucidate the rate- and enantiodetermining step of this important reaction. The results of these studies support a cyclization-induced rearrangement mechanism and prompted DFT studies (B3LYP/LACVP**+) of C-N bond formation, believed to be the enantiodetermining step of this catalytic cycle. On the basis of these calculations, a model for enantioinduction was developed, in which the planar chirality of the catalyst controls the enantioselectivity. These studies should allow the rational design of more enantioselective catalysts.
Watson
Mary P
MP
Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, California 92697-2025, USA.
Overman
Larry E
LE
Bergman
Robert G
RG
D000081:Acetamides; D002384:Catalysis; D062845:Chloroacetates; D003198:Computer Simulation; D007700:Kinetics; D008024:Ligands; D008956:Models, Chemical; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism; D014238:Trichloroacetic Acid / Q000737:chemistry
D000081:Acetamides; D062845:Chloroacetates; D008024:Ligands; D010165:Palladium; D014238:Trichloroacetic Acid; C009528:trichloroacetamide