Formation of aldehydes and ketones via reduction of alkyl monohalides by electrogenerated nickel(I) salen in dimethylformamide in the presence of water, oxygen, and light

Addition of a stoichiometric amount of a primary alkyl monohalide (1-bromooctane) to a solution of electrogenerated nickel(I) salen in dimethylformamide containing water, followed by irradiation with a xenon arc lamp and brief exposure to air, results in the formation of an aldehyde (1-octanal). Analogous experiments with a secondary alkyl monohalide (2-bromohexane) afford a ketone. Other products are alkanes, alkenes, and dimers that arise from classic radical coupling and disproportionation of alkyl radicals.