Catalytic Hydration of Benzonitrile and Acetonitrile using Nickel(0)

The homogeneous catalytic hydration of benzo‐ and acetonitrile under thermal conditions was achieved using nickel(0) compounds of the type [(dippe)Ni(η2‐NCR)] with R=phenyl or methyl (compounds 1 and 2, respectively), as the specific starting intermediates. Alternatively, the complexes may be prepared in situ by direct reaction of the precursor [(dippe)NiH]2 (3) with the respective nitrile. Hydration appears to occur homogeneously, as tested by mercury drop experiments, producing benzamide and acetamide, respectively. Addition of Bu4NI did not lead to catalysis inhibition, suggesting the prevalence of Ni(0) intermediates during catalysis. Hydration using analogous complexes of 3, such as [(dtbpe)NiH]2 (4) and [(dcype)NiH]2 (5) was also addressed.