Enantioselective Organocatalytic Michael Addition to Unsaturated Indolyl Ketones.

An efficient enantioselective organocatalytic method for the synthesis of -alkylated indoles with α-branched alkyl substituents from the corresponding unsaturated indolyl ketones via a Michael addition has been developed. The resulting products were obtained in high enantioselectivities and in good yields. Various nucleophiles (nitroalkanes, malononitrile, malonic esters) can be used.