460343-59-3Relevant academic research and scientific papers
Cleavage of carbon-carbon bonds in aromatic nitriles using nickel(0)
Garcia, Juventino J.,Brunkan, Nicole M.,Jones, William D.
, p. 9547 - 9555 (2002)
The nickel(0) fragment [(dippe)Ni] has been found to react with a variety of aromatic nitriles. Initial π-coordination to the C=C and CN bonds of 2-cyanoquinoline is found to lead ultimately to C-CN oxidative addition. 3-Cyanoquinoline reacts similarly, although no η2-CN complex is observed. 2-, 3-, And 4-cyanopyridines react initially to give η2-nitrile complexes that then lead to quantitative formation of C-CN oxidative addition products. Benzonitrile reacts similarly but undergoes reversible insertion into the Ph-CN bond to give an equilibrium mixture of Ni(II) and Ni(0) adducts. A series of para-substituted benzonitriles has been studied in terms of both the position of the equilibrium between (dippe)Ni(η2-arylnitrile) (dippe)-Ni(CN)(aryl) and the rate of approach to equilibrium, and the Hammett plots indicate a buildup of negative charge at the ipso carbon both in the transition state and the Ni(II) product. Terephthalonitrile gives both η2-nitrile and oxidative addition adducts, as well as dimetalated products. No C-C or C-N cleavage of the aromatic ring is seen with quinoline or acridine; only η2-arene complexes are formed. The structures of many of these compounds are supported by x-ray data.
