Michael Addition of Ketones and Aldehydes to Maleimides Catalyzed by Modularly Designed Organocatalysts

Modularly designed organocatalysts (MDOs) formed in situ from the self-assembly of primary -amino acids and Cinchona alkaloid thioureas were found to be excellent catalysts for the stereoselective Michael addition of enolizable ketones and aldehydes to maleimides. Using an MDO formed from quinidine thiourea and L-2-chlorophenylglycine, the corresponding Michael addition products, 3-substituted succinimides, may be obtained in excellent yields and high enantio- and diastereoselectivities.