Abstract

A novel tertiary amine squaramide has been successfully developed and applied to catalyze the asymmetric Michael addition between cyclic diketones and β,γ-unsaturated α-ketoesters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of synthetically and pharmaceutically useful chiral bicyclic compounds were obtained with both high yields (up to 97%) and excellent enantioselectivities (up to 97% ee).

Keywords: Michael addition, organocatalysis, tertiary amine-squaramide, cyclic diketone, βγ-unsaturated α-ketoesters, isosteviol derivative.