Nickel-catalysed methylation of ketones by trimethylaluminium

Abstract

Nickel acetylacetonate catalyses the methylation of ketones to methyl carbinolates by trimethyl-aluminium. Concurrently it also catalyses other reactions of trimethylaluminium with ketones. Most notable of these is the gem-dimethylation of acetophenone to t-butylbenzene; a few aryl ketones undergo similar gem-dimethylation, and p-acetoxyacetophenone gives p-t-butylphenyl acetate.     Several other nickel compounds are effective. A mechanism for the catalysis is suggested which involves oxidative addition of trimethylaluminium to zerovalent nickel.