Combining proline and 'click chemistry': a class of versatile organocatalysts for the highly diastereo- and enantioselective Michael addition in water

Based on 'click chemistry' conditions, a class of novel, facile, versatile pyrrolidine-based triazole derivatives were prepared, and proved to be efficient catalysts for the highly diastereoselective and enantioselective Michael addition of ketones to nitroalkenes. The Cu(I)-catalyzed 1,3-dipolar 'click' azide-alkyne cycloaddition provides modular and tunable features for the pyrrolidine-based triazole organocatalysts, and the resulting triazole moiety can serve as a phase tag to complete the reaction in water with an excellent yield and high enantiomeric excess. (c) 2007 Elsevier Ltd. All rights reserved.