Cleavage of carbon-carbon bonds in alkyl cyanides using nickel(0)

The reaction of the complex [(dippe)NiH](2) (1) with a variety of alkyl cyanides afforded nickel(0) compounds of the type [(dippe)Ni(eta(2)-RCN)], where R, = Me, Et, Pr, Pr-i, Bu-t, cyclopropyl, cyclobutyl, adamantyl (2-9, respectively). When compounds 2-9 were warmed to yield oxidative addition products, the thermal reaction proceeded only in the case of 2 to produce [(dippe)Ni(Me)(CN)](10). Photochemical activation did produce oxidative addition products from compounds 2-8, which rapidly evolved to the beta-elimination products of the organic moiety in most cases and to the formation of [(dippe)Ni(CN)(2)] (11). Reaction of 1 with acetonitrile in the presence of BPh3 gives [(dippe)Ni(eta(2)-MeCNBPh3)](12), which does not undergo thermal C-CN cleavage upon heating. X-ray crystal structures are reported for 10-12.