Fe-BPsalan complex catalyzed highly enantioselective Diels–Alder reaction of alkylidene β-ketoesters

Abstract

A practical, highly efficient iron-catalyzed asymmetric Diels–Alder reaction of various alkylidene β-ketoesters with dienes was developed. Both cyclic and acyclic alkylidene β-ketoesters underwent the reaction well with the Fe-BPsalan complex as the catalyst to afford the addition products including estrone analogues in excellent yields, good to high diastereoselectivities and excellent enantioselectivities under mild reaction conditions. DFT calculations revealed the critical role of the steric effect in directing the reaction selectivity.