Catalysis of highly stereoselective Mannich-type reactions of ketones with α-imino esters by a pyrrolidine-sulfonamide.: Synthesis of unnatural α-amino acids

The novel pyrrolidine-sulfonamide I has been prepared and used successfully to catalyze Mannich-type reactions between ketones and alpha-imino esters. The process is used to efficiently synthesize functionalized alpha-amino acid derivatives with excellent levels of regio-, diastereo-, and enantio-selectivity. (C) 2004 Elsevier Ltd. All rights reserved.