Enantioselective one-pot synthesis of α-amino esters by a phosphine-catalyzed [3+2]-cycloaddition reaction

Abstract

Phosphines go one-pot: The one-pot synthesis of cyclic α-amino esters from azlactones and allenes by a phosphine-catalyzed [3+2]-cycloaddition reaction followed by a ring opening of the azlactone moiety is presented. The products are isolated as single regioisomers in good overall yields and high enantioselectivities (up to 95% ee). The possibility for easy modifications of the obtained products was demonstrated by synthesizing an amino acid and an α-hydroxy-β-ketoester. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.