Secret revealed: The mechanism of the catalytic hydrodefluorination of pentafluorobenzene by the N-heterocyclic carbene complex [Ru(IMes)(PPh 3)2(CO)H2] has been investigated by DFT calculations. Two sets of novel pathways (concerted and stepwise) have been defined whereby a Ru H ligand can act as a nucleophile at the fluoroarene substrate. The most accessible pathway equates to the formation of 1,2,3,4-C6F4H2 and thus accounts for the unusual regioselectivity that is observed experimentally (see scheme). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
- C-F activation
- density functional calculations