Structure of a Novel Rhodium Phosphinite Compound: Agostic Interactions as a Model for an Oxidative Addition Intermediate

Pincer ligand metalation is presumed to proceed via initial coordination to the phosphorus atoms followed by C–H oxidative addition. Few isolated intermediates in this process are known. A rhodium phosphinite complex has been isolated and structurally characterized that exhibits a strong agostic interaction with a C–H bond in the ligand backbone. The [(tBuPOCOP)­Rh­(CO)­H]+ system exhibits greater acidity and reactivity than the analogous iridium species (tBuPOCOP = κ3-C6H3-1,3-[OP­(tBu)2]2).