Cooperative bimetallic catalysis in asymmetric allylic substitution.

Synergistic catalysis is gaining increasing attention due to its advantages over traditional catalytic methodologies, such as improved catalytic activity, broader substrate scope, increased selectivity and lower cost. Methodologies involving the synergistic combination of metal catalysts and organocatalysts have been intensively studied. Given the clear benefits of bimetallic catalyst systems consisting of two distinct metal catalysts, cooperative bimetallic catalysis has proved to be successful for a number of difficult asymmetric transformations. This review highlights the recent advances in bimetallic systems for catalytic asymmetric allylic substitution reactions. Strategies using a chiral metal catalyst and the cooperative effect of a second achiral metal catalyst for asymmetric transformations are discussed. Additionally, several challenging asymmetric reactions realized by employing two different chiral metal catalysts in a synergistic manner are also covered.