ON THE LEWIS ACIDITY OF NICKEL(0) .12. DIMETHYLALUMINUM HYDRIDE COMPLEXES OF NICKEL(0)

On the Lewis Acidity of Nickel(0). XII. ‐ Dimethylaluminium Hydride Complexes of Nickel(O) Ni(CDT) reacts with (1‐azabicyclo[2.2.2]octane)dimethylaluminium hydride in pentane to form the yellow crystaline addition compound (C7H13N)(Me2AlH)Ni(CDT) (2c). In its crystal structure 2c exhibits a Ni–H–Al three‐center bond. Displacement of the CDT ligand of 2c with ethene in pentane at 0°C yields light brown crystals of (C sb7H13N)(Me2AlH)Ni(C2H4)2 (4), which is also obtained from Ni(C2H4)3 and (C7H13N)‐Me2AlH). Complex 4 is converted by CO at – 78°C into the colorless carbonyl complex (C7H13N)(Me2AlH)Ni(CO)3 (5). 2c and 4 may be considered as model compounds for intermediates of the nickel(0)‐catalyzed hydroalumination reaction of alkenes. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim