Selective hydration of nitriles to amides catalysed by PCP pincer supported nickel(II) complexes.

The (PCP)Ni-OH complexes (R = (i)Pr, (t)Bu, Cy) are effective catalyst precursors for the selective hydration of nitriles to the corresponding amides under relatively mild conditions (80 °C) and low catalyst loadings (0.05-0.5%). Substrate scope includes aliphatic, vinylic and aromatic nitriles, but substrates with protic groups poison the catalyst abruptly. The catalysts are effective because the electron rich nature of the PCP ligands and their steric bulk renders the hydroxo group labile.