Study concerning the effects of chelation on the structure and catalytic activity of ruthenium carbene complexes

The ruthenium chelate complexes 4 and 5 were prepared by reaction of the Grubbs catalyst 1 and its second-generation analogue 2 with the 2-vinylbenzoic acid isopropyl ester 3 in the presence of CuCl. The fact that the chelating carbonyl group in these complexes attenuates their catalytic activity sets an experimental basis for the interpretation of reactivity data previously described in the literature.