The Fluoro Analogue of Wilkinson's Catalyst and Unexpected Ph−Cl Activation^†

The fluoro analogue of Wilkinson's catalyst, [(Ph₃P)₃RhF] (1), was synthesized and fully characterized. Both solution behavior and solid-state geometry parameters of 1 were found to be surprisingly similar to those of Wilkinson's catalyst. Unlike Wilkinson's catalyst however, 1 exhibited most unusual reactivity toward the notoriously inert C−Cl bond of nonactivated chloroarenes. The novel Ph−Cl activation with 1 includes fluorine transfer from the metal to a phosphine ligand and evidently phenyl transfer from the phosphine to Rh to produce an electron-rich σ-phenylrhodium intermediate.