CARBON-CARBON COUPLING REACTIONS BETWEEN METALLACARBYNES CP(CO)(2)M-CR AND CYCLOPALLADATED LIGANDS - SYNTHESIS OF A NOVEL CLASS OF PALLADIUM MU-ALKYLIDENE COMPLEXES

The carbyne carbon atom of metallacarbynes such as (eta(5)-C5H5)(CO)(2)M=CR (where M = Mo, W and R = p-tolyl, 4-tert-butylphenyl, 2,6-dimethylphenyl, 1-cyclopentenyl) is readily coupled with the palladated carbon atom of various cyclopalladated compounds. This reaction affords good to excellent yields of novel mu-alkylidene complexes whose structure is maintained irrespective of the palladated ligand employed. For example, the reaction of(eta(5)-C5H5)(CO)(2)-Mo=C-p-Tol with [2-Me(2)NCH(2)C(6)H(4)PdCl](2) affords [2-Me(2)NCH(2)C(6)H(4)(eta(3)-{mu-C(p-Tol)Mo(mu-CO)}-C5H5(CO)PdCl].