Catalytic Asymmetric Ring-Opening Reactions of Aziridines with 3-Aryl-Oxindoles

Abstract

A highly enantioselective ring-opening alkylation reaction between 3-aryl-oxindole and N-(2-picolinoyl) aziridine has been realized for the first time. The reaction is efficiently mediated by a simple in-situ-generated magnesium catalyst and 3,3'-fluorinated-BINOL (BINOL=1,1'-binaphthalene-2,2'-diol) has been identified as a powerful chiral ligand. Notably, the fluorine atom on the chiral ligand plays a key role in providing the desired chiral 3-alkyl-3-aryl oxindoles with excellent enantioselectivities.

Keywords: 3,3′-fluorinated-binol; aziridines; magnesium catalysis; oxindoles; ring-opening reactions.