863676-94-2Relevant academic research and scientific papers
Hydroalumination of nitriles and isonitriles
Uhl, Werner,Matar, Madhat
, p. 1214 - 1222 (2007/10/03)
Hydroalumination of H5C6-C≡N with di(tert-butyl)aluminum hydride 1 or the corresponding di-ethyl compound 2 yielded the products tBu2Al-N=C(C6H5)H 3 and Et2Al-N=C(C6H5)H 4, respectively, both of which form dimers possessing Al2N2 heterocycles with two exocyclic C=N double bonds. NMR spectroscopic data indicate the occurrence of cis/trans isomers in solutions of compound 4. The dimerization of the imide via Al-N interactions was prevented by employing the hydride [(Me 3Si)2HC]2AlH 6 bearing the bulky bis(trimethylsilyl)methyl substituents. Its reaction with benzonitrile yielded the compound R2Al-N=C(C6H5)H(N≡C-C 6H5) 7 [R = CH(SiMe3)2], in which the coordinative saturation of the aluminum atoms was achieved by adduct formation with one molecule of the starting nitrile. In these cases the C≡N triple bond inserted completely into the Al-H bond of the hydride. In contrast, the reaction of tert-butyl isonitrile afforded the product tBu 2Al-C(H)=N-C6H5 8 by the insertion of its terminal carbon atom into the Al-H bond. Hence, it has a geminal arrangement of the aluminum and hydrogen atoms. Dimerization of 8 yielded a six-membered heterocycle. Hydroalumination does not occur upon treatment of the hydride 1 with trimethylsilylnitrile. Instead, the Si-CN bond was cleaved, and the aluminum cyanide (tBu2Al-C≡N)4 9 was isolated in a high yield.
