Direct asymmetric aza Diels-Alder reaction catalyzed by chiral 2-pyrrolidinecarboxylic acid ionic liquid

The utility of [EMlm][Pro] as an efficient catalyst for the one-pot direct asymmetric aza Diels-Alder reaction has been developed. A set of cyclic alpha,beta-unsaturated ketones have been explored in up to 93% yield with up to >99/1 dr and >99% ee. Moreover, the catalytic system can be recycled and reused for six times without any significant loss of catalytic activity. (C) 2009 Elsevier B.V. All rights reserved.