DBU-promoted trifluoromethylation of aryl iodides with difluoromethyltriphenylphosphonium bromide (DFPB) in the presence of copper source is described. In this transformation, DBU not only acts as base to deprotonate the difluoromethyl group in DFPB to generate difluoromethylene phosphonium ylide Ph₃P⁺CF₂⁻, but also converts the difluorocarbene generated from ylide Ph₃P⁺CF₂⁻ into trifluoromethyl anion, finally resulting in the trifluoromethylation of aryl iodides. The reactions proceeded smoothly to afford expected products in moderate to good yields.

Au^I/Cu^I-co-catalyzed tandem 1,3-acyloxy migration/trifluoromethylation reaction of propargyl esters to give α-trifluoromethyl enones in moderate yields and with excellent stereoselectivity is described. It is proposed that the reaction proceeds through the 1,3-acyloxy migration of the propargyl esters catalyzed by Au^I to produce an allenic intermediate, followed by its trifluoromethylation to give the final product.