Metathesis Catalysts with Fluorinated Unsymmetrical NHC Ligands

The
synthesis of new fluorinated ruthenium­(II) carbene second-generation
precatalysts with unsymmetrical N-heterocyclic carbene ligands has
been developed. The reaction profiles of these complexes have been
studied in RCM with model substrates such as diethyl diallyl- and
allylmethallyl-malonate, and CM model reaction of allylbenzene with
1,4-diacetoxybut-2-ene. In olefin metathesis reactions, the new fluorinated
second-generation Grubbs complexes exhibit comparable activity with
respect to commercially available Grubbs catalysts. On the other hand,
in RCM reactions, the Hoveyda-type catalysts present a latent character,
which is not present in the classical second-generation Hoveyda catalyst.