Applications of enantiopure 4,5-diphenyl substituted box and pybox ligands in asymmetric catalysis

Enantioselectivities of 95-98% have been obtained in the palladium-catalyzed alkylation of rac-3-acetoxy-1,3-diphenyl-1-propene with dimethyl malonate using 4,5-diphenyl substituted bis(oxazoline) as the chiral ligands, whatever the configuration at C-5. The copper-catalyzed allylic oxidation of various cycloalkenes gave the corresponding allylic esters with enantioselectivities up to 84% using the 4,5-diphenyl substituted bis(oxazoline). Lower enantioselectivities were obtained using the corresponding 4,5-diphenyl substituted pyridine-bis(oxazoline), the higher enantioselectivity being observed with the cis-stereoisomer. (C) 2004 Elsevier Ltd. All rights reserved.