A copper-catalyzed O-methylation of carboxylic acids using dimethyl sulfoxide (DMSO) as the methyl source is disclosed. This transformation exhibits a broad substrate scope and excellent functional group tolerance. Mechanistic studies indicate that a methyl radical is generated from dimethyl sulfoxide in the reaction process.
Key words
carboxylic acids - O-methylation - dimethyl sulfoxide - hydrogen peroxide - methyl radical - esterification - esters