Synthesis of Trifluoromethylated Dibenzoxepines via Palladium-Catalyzed Tandem C–O Bond Formation/C–H Arylation

A palladium-catalyzed cyclization reaction of phenols with trifluoromethyl-containing -bromo-β-chlorostyrenes has been developed. In the presence of palladium(II) acetate, tricyclohexylphosphine, and cesium carbonate, a variety of 6-trifluoromethyldibenzo[,]oxepines were prepared in moderate to good yields through the tandem O-alkenylation of general phenols and subsequent C-H arylation.