Copper-mediated 1,2-bis(trifluoromethylation) of arynes

We herein describe an unprecedented 1,2-bis(trifluoromethylation) of arynes with [CuCF₃] in the presence of an oxidant DDQ. The method allows the rapid construction of a new class of 1,2-bis(trifluoromethyl)arenes in one-step from aryne precursors under mild conditions. Its synthetic utility has been demonstrated in the preparation of bis(trifluoromethylated) molecules with potential pharmaceutical and materials science applications. Mechanistic studies indicated the presence of an o-trifluoromethyl aryl radical intermediate via CF₃ group transfer from [CuCF₃] to the aryne.