Water-promoted regio-selective trifluoromethylation of vinyl conjugated diazoacetates

An efficient trifluoromethylation reaction of vinyldiazoacetates under mild reaction conditions was depicted. Pre-generated CuCF3 was used as a trifluoromethylation reagent and water acted as both a promoter and proton source. The reaction is compatible with a broad scope of functional groups and easy to scale-up. The wide functional group tolerance of the reaction enables further synthetic manipulation of the products.