Amine-catalyzed cascade synthesis of 3,4-diunsubstituted coumarins

Abstract

We disclose an efficient route to synthesize 3,4-diunsubstituted coumarins through a cascade organocatalytic reaction. The reaction is catalyzed by using of a combination of benzylamine (10 mol-%) and triethylamine (10 mol-%). Various salicylaldehydes were tested, and the corresponding coumarin products were obtained in good to high yields under mild and metal-free reaction conditions. We disclose an efficient route to synthesize 3,4-diunsubstituted coumarins through a cascade organocatalytic reaction. The reaction is catalyzed by using of a combination of benzylamine (10 mol-%) and triethylamine (10 mol-%). Various salicylaldehydes are tested, and the corresponding coumarin products are obtained in good to high yields under mild and metal-free reaction conditions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.