Rhodium-Catalyzed Reductive Aldol Reactions Using Aldehydes as the Stoichiometric Reductants

摘要

Transition metal catalyzed reductive aldol reactions are proving to be valuable synthetic tools.They allow the required enolates to be generated regioselectively in situ,can be catalyzed by a number of different metals,and have recently been shown to deliver good levels of diastereo- and enantioselectivity.Despite these attributes,there still remain limitations stemming from the use of stoichiometric reductants,such as silanes or molecular hydrogen.In particular,the formation of side products,such as enol silanes,or C-C or C-O double-bond reduction products,can be responsible for reduced efficiency.In this Communication,we report the development of a versatile new reductive aldol process that employs aldehydes as the stoichiometric reductants.