Cleavage of Carbon−Carbon Bonds in Alkyl Cyanides Using Nickel(0)

Abstract

The reaction of the complex [(dippe)NiH]2 (1) with a variety of alkyl cyanides afforded nickel(0) compounds of the type [(dippe)Ni(η2-RCN)], where R = Me, Et, Pr, iPr, tBu, 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 β-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(η2-MeCNBPh3)] (12), which does not undergo thermal C−CN cleavage upon heating. X-ray crystal structures are reported for 10−12.