Enantioselective3+2-Cycloadditions Catalyzed by a Protected,Multifunctional Phosphine-Containing alpha-Amino Acid

摘要

alpha-Amino acids are receiving explosive attention as catalysts for organic reactions.The catalysis exhibited by proline is perhaps most versatile,although there is now a growing list of reactions that may be catalyzed by other amino acids,including both proteinogenic and nonproteinogenic variants.Concerning the latter,"unnatural"amino acids have also proven important as ligands for metal-catalyzed reactions.