Organocatalytic enantioselective indole alkylations of α,β-unsaturated ketones

The C3-selective enantioselective Michael-type Friedel - Crafts alkylations of indoles with nonchelating alpha, beta-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 degrees C. Moderate to good ee ( 47 - 89%) has been achieved.