Organocatalytic enantioselective indole alkylations of α,β-unsaturated ketones

Abstract

The C3-selective enantioselective Michael-type Friedel–Crafts alkylations of indoles with nonchelating α,β-unsaturated alkyl ketones, catalysed by a chiral primary amine derived from natural cinchonine, were investigated. The reactions, in the presence of 30 mol% catalyst, were smoothly conducted at 0 to −20 °C. Moderate to good ee (47–89%) has been achieved.