Isocyanate Insertion into a La-P Phosphide Bond: A Versatile Route to Phosphaureate-Bridged Heterobimetallic Lanthanide-Coinage-Metal Complexes.

A new route to heterobimetallic lanthanide-coinage-metal complexes is disclosed. The selective insertion of organic substrates such as phenyl iso(thio)cyanate into the La-P bond of the primary phosphido complex () (with PN = (-(2-(diisopropylphosphanyl)-4-methylphenyl)-2,4,6-trimethylanilide) yields the phospha(thio)ureate complexes () and () with retention of the P protons. Subsequent deprotonation of the phosphaureate complex with potassium hexamethyldisilazide (KHMDS, K[N(SiMe)]) leads to the polymeric complex (). Complex was found to be an excellent precursor for salt metathesis reactions with copper(I) and gold(I) chlorides supported by an N-heterocyclic carbene (NHC, and ) or a cyclic alkyl amino carbene (CAAC, and ). This resulted in the unprecedented formation of heterobimetallic lanthanum-coinage-metal complexes, containing the first example of a μ,κ(,):κ()-phosphaureate bridging ligand. For an alternative route to complex a direct protonolysis protocol between a new basic gold(I) precursor, namely , and was also investigated. The complexes have been characterized by multinuclear NMR spectroscopy, IR spectroscopy, and X-ray crystallography (except for ).