Photoredox-Catalyzed Chlorotrifluoromethylation of Arylallenes: Synthesis of a Trifluoromethyl Building Block.

A new class of trifluoromethyl building blocks─2-trifluoromethyl allyl chlorides─have been obtained through a photoredox-catalyzed chlorotrifluoromethylation of aryl allenes. The reaction proceeded in a regio- and stereoselective manner. A trifluoromethylated analog of the flunarizine drug was synthesized.