Ionic liquid-supported proline as catalyst in direct asymmetric aldol reaction

Ionic-liquid-supported proline derivative was synthesized starting from L-proline and was used to catalyze direct asymmetric aldol reaction of acetone with aldehydes. The yield and optical purity of the condensation products, the corresponding beta-hydroxy carbonyl compounds were comparable with those obtained under homogeneous conditions. Moreover, the catalyst can be reused for at least four times.