Copper-catalyzed trifluoromethylalkynylation of isocyanides.

The title reaction proceeds with acetylenic triflones and isocyanides under mild conditions using copper as a catalyst. This transformation provides an efficient access to (E)-N-alkyl trifluoromethyl alkynyl ketoimines, which are useful building blocks for the synthesis of CF3-containing N-heterocycles, propargylamines, etc.