Copper-catalyzed cyclization reaction: synthesis of trifluoromethylated indolinyl ketones

A novel, simple, effective and rapid synthetic method to construct the corresponding C-2 trifluoromethylated indolinyl ketones via a copper-catalyzed cyclization reaction between N-alkylaniline and -(trifluoromethyl)-α,-unsaturated enones was developed. The control experiments elucidate that the reaction maybe involve a radical mechanism through a single-electron transfer process. Moreover, a broad substrate scope and good functional group, highly diastereoselectivities (up to > 20:1) as well as gram-scale synthesis make this approach highly attractive