Copper-catalyzed cyclization reaction: synthesis of trifluoromethylated indolinyl ketones†

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

Automated summary

A novel, simple, effective, and rapid synthetic method has been developed for constructing C-2 trifluoromethylated indolinyl ketones via a copper-catalyzed cyclization reaction. The reaction likely involves a radical mechanism through a single-electron transfer process, with broad substrate scope, good functional groups, high diastereoselectivities (up to >20:1), and gram-scale synthesis, making this approach highly attractive.