New Prolinamides with Isosteviol Skeleton as Efficient Organocatalysts for the Direct Asymmetric Aldol Reaction

In this work, two new prolinamides with isosteviol skeleton were synthesized and used as chiral catalysts for the asymmetric aldol reaction. Solvent effects, catalyst loading, substrate scope and the influence of water on the reaction were investigated. With only 5 mol % loading, the synthesized catalysts showed excellent activity (up to 98% yield) and good stereoselectivity (up to 87:13 dr, 90% ee) for the direct aldol reaction of cyclohexanone and substituted benzaldehydes at room temperature. Keywords: Aldol reaction, asymmetric catalysis, isosteviol, organocatalyst, prolinamide, synthesis.