Reduction of alkyl halides by electrogenerated cobalt(I) salen and nickel(I) salen: reactions of alkyl radicals with no and O_2

摘要

Cobalt(I) salen, electrogenerated in DMF containing 0.10 M TMABF_4, oxidatively adds to (2-bromoethyl)benzene to form (2-phenylethyl)cobalt(III) salen, which undergoes photolysis to afford the 2-phenylethyl radical and cobalt(II) salen. In the presence of nitric oxide, the alkyl radical reacts to give an oxime and a nitrile. When an alkyl halide (1-bromooctane) is introduced into a solution of electrogenerated nickel(I) salen in DMF-0.10 M TMABF_4 containing added water, followed by exposure of the mixture both to ultraviolet-visible light and to air (or oxygen), the corresponding aldehyde (octanal) can be obtained in a yield of up to 74%.