Highly enantioselective catalytic Friedel-Crafts reactions of cyclic α-alkylidene β-oxo imides

Highly enantioselective catalytic Friedel-Crafts reactions of cyclic alpha-alkylidene beta-oxo imides with indole, pyrrole, and furan derivatives at relatively low temperatures are described. The X-ray crystallographic analysis of the product revealed that the sense of enantioselectivity of the Friedel-Crafts reactions could be well explained by the proposed chelate model. The model was stabilized by an intramolecular hydrogen bond, wherein the cyclic alpha-alkylidene beta-oxo imide coordinates with Cu(II) through the two imide carbonyls. (C) 2015 Elsevier Ltd. All rights reserved.