ENANTIOSELECTIVE HOMOGENEOUS CATALYSIS INVOLVING TRANSITION-METAL ALLYL INTERMEDIATES

Enantioselective catalysis via transition metal-allyl intermediates is a powerful methodology for the synthesis of enantiomerically enriched compounds. Optical yields of up to 96% have been obtained by using this methodology. One of the most impressive features of this methodology is the ability to replace existing centers of chirality of chiral racemic compounds with new centers of desired configuration. The rich reaction chemistry of transition-metal-allyl complexes can be exploited for the catalytic synthesis of carbon-carbon as well as carbon-heteroatom bonds from a variety of different substrates. In this review, we summarize the results achieved in the field of enantioselective synthesis by transition metals where allylic intermediates are most likely involved in the catalytic cycle to form new carbon-carbon or carbon-heteroatom bonds. An important aim of the review is not only to summarize important contributions to this field but to attempt to organize the results in a meaningful and mechanistically significant way.