Insertion reactions of heterocumulene into metal-ligand bonds

Published and authors’ own data on the typical examples of behavior of organic iso(thio)cyanates and other unsaturated substrates in reactions with metal-heteroatom bonds-M-O, M-N, M-P, and M-Hal-are reviewed. A possibility of multiple insertion of heterocumulenes into the same M-L bond and their ability to undergo-sphere condensation with other ligands upon heteromolecular insertion as well as the cocyclization of inserted ligands upon complex will be discussed in this review. Factors that affect the direction of iso(thio)cyanate addition to upon metal-heteroatom bond as well as the possibility of different kinds of their combination for the formation of heterocyclic ligands or compounds are also. Most of the findings are based on the results of IR and NMR spectroscopical, as well as X-ray structural studies.