Catalytic asymmetric inverse-electron-demand (IED) [4+2] cycloaddition of salicylaldimines: Preparation of optically active 4-aminobenzopyran derivatives

Abstract

The catalytic asymmetric inverse-electron-demand (IED) [4+2] cycloaddition of various salicylaldehyde-derived N-arylimines with electron-rich alkenes in the presence of chiral BINOL-derived phosphoric acid catalysts has been studied with the aim of obtaining optically active 4-aminobenzopyran derivatives. Dienophiles such as 2,3-dihydro-2H-furan, benzyl N-vinylcarbamate and 2-vinylindole have been employed. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.