Liberation of methyl acrylate from metallalactone complexes via M–O ring opening (M = Ni, Pd) with methylation agents

Ring opening of various nickela- and palladalactones induced by the cleavage of the M–O bond by methyl trifluoromethanesulfonate (MeOTf) and methyl iodide (MeI) is examined. Experimental evidence supports the mechanism of ring opening by the alkylating agent followed by β-H elimination leading to methyl acrylate and a metal-hydride species. MeOTf shows by far higher efficiency in the lactone ring opening than any other methylating agent including the previously reported methyl iodide.