Novel Tripod l-ProlinamideCatalysts Based on Tribenzyl- and Triphenyl-phosphineOxide for the Direct Aldol Reaction

A series of C 3 -symmetric triprolinamide catalysts based on triphenyl- and tribenzylphosphine oxide has been developed to catalyze the direct asymmetric aldol reaction of aromatic aldehydes and cyclohexanone. Under the optimal conditions, high isolated yield (up to 96%), diastereoselectivities (up to 88:12) and enantioselectivities (up to 97% ee) were obtained.