InBr3-catalyzed Friedel-Crafts addition of indoles to chiral aromatic epoxides: a facile route to enantiopure indolyl derivatives.

Aromatic optically active epoxides can be opened in a regioselective and clean way with indoles in the presence of catalytic amount of InBr3 (1 mol %). The reaction takes place with a SN2 pathway affording the 2-aryl-2-(3'-indolyl)ethan-1-ols with excellent enantioselectivity (ee up to 99%).