Oxidative Olefination of Polyfluoroarenes Catalyzed by Palladium

Key words

palladium - thioether - polyfluoroarenes

Significance

The dehydrogenative Heck reaction represents a more environmentally friendly variant of the classic Nobel prize winning transformation, as it makes use of non-prefunctionalized substrates. Polyfluoroarenes are important structural motifs, and the development of new methods to incorporate them in an efficient manner is an important endeavor. The report represents a rare example of a thioether promoted C−H functionalization of electron-deficient arenes.

Comment

The authors report a palladium-catalyzed methyl phenyl sulfide promoted direct olefination of polyfluoroarenes. These previously ‘unreactive’ substrates undergo facile transformation with the specifically chosen sulfur-containing ligand. Products are obtained in good to excellent yields and with high E/Z selectivities. A competition reaction between pentafluorobenzene and both styrene and tert-butyl acrylate show that there is no bias between electron-rich and electron-deficient olefins under the reported conditions.