A Fluorous Proline Catalyst Immobilized on Teflon® for Highly Stereoselective Asymmetric Aldol Reactions

Abstract

An immobilized fluorous-tagged proline catalyst and its application as a recycling system in highly stereoselective asymmetric aldol reactions are described. The introduction of acidic sulfonamide groups bearing multifluorous tags at the carboxy position proved to be more effective than the introduction of bulky substituents on the proline backbone to achieve high stereoselectivity. The Teflon (R)-immobilized proline catalyst could be recovered and reused at least five times while maintaining high levels of catalytic activity and stereoselectivity.