Easy Access to Difluoromethylene-Containing Arene Analogues through Palladium-Catalysed C-H Olefination

An efficient palladium-catalysed ortho-C-H olefination of ,-difluorophenylacetic acid derivatives using 8-aminoquinoline as a bidentate directing group has been developed. A range of olefinated arenes can thus be synthesized in a concise way. This reaction provides an easy and straightforward route to a panel of difluoromethylated arene analogues in moderate to good yields, with a satisfactory tolerance of common functional groups. Transformation of the products into a variety of other difluoromethylene-containing compounds demonstrates the utility of this method.