Chiral Oligomers by Iterative Tandem Catalysis

摘要

Tandem catalysis,that is,combined catalytic reactions without intermediate product recovery,attracts increasing interest from academia and industry as an alternative to multistep synthetic procedures.Evidently,by carrying out multiple transformations in one pot,a substantial improvement in both the economics and the environmental acceptability of the process can be achieved.In concurrent tandem catalysis,multiple catalysts are operating simultaneously in a cooperative fashion.A prominent example is the dynamic kinetic resolution (DKR) of secondary alcohols.In this process,a racemic mixture is completely converted into one enantiomer by coupling enzyme-catalyzed kinetic resolution to ruthenium-catalyzed racemization.To date,concurrent tandem catalysis has not been employed in an iterative way.