Direct oxide transfer from an η-keto ligand to generate a cobalt PCP(O) pincer complex.

We report the direct carbonyl cleavage in a κ-P',(η-C,O),P'' ligand by a monomeric cobalt centre through metal-ligand cooperativity. C-O cleavage leads to the formation of a PCP(O) pincer ligand with a central alkylidene anchor. A DFT analysis, supported by kinetic studies, suggests that decoordination of a pincer phosphino arm to generate a kinetically accessible free phosphine may be critical in transfer of the oxide to a phosphorus position. Thus, oxide transfer to bisphosphino bidentate co-ligands was also found to be viable, allowing access to the previously reported PCP pincer complex (2), where bisphosphines were used as oxide sequestering agents.