Highly Enantioselective Synthesis of α-Amino Acid Derivatives by an NHC-Catalyzed Intermolecular Stetter Reaction

PROTONtype: An NHC-catalyzed (NHC=N-heterocyclic carbene), highly asymmetric intermolecular Stetter reaction allows the atom-economic and efficient formation of valuable α-amino acid derivatives (see scheme); the key step is an intramolecular stereoselective protonation. For the first time, a β-unsubstituted Michael acceptor was employed successfully in this kind of reaction, most importantly, with a broad range of different aldehydes. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.