Novel axially chiral bis-arylthiourea-based organocatalysts for asymmetric Friedel-Crafts type reactions

It has been shown that catalytic amounts (10-20 mol %) of novel axially chiral bis-arylthioureas promote the asymmetric organocatalytic Friedel-Crafts type addition of indole and N-methylindole to nitroolefins. The optimum catalyst is capable of promoting the reaction between challenging substrates such as N-methylindole and nitroolefins bearing aliphatic beta-substituents with enantioselectivity unprecedented for an organocatalytic system. (c) 2006 Elsevier Ltd. All rights reserved.