Nitrosonium Tetrafluoroborate-Promoted α,α-Diacetoxylation of Aryl Methyl Ketones.

α,α-Diacetoxylation of methyl aryl ketones was achieved using NOBF4 under mild, metal-free conditions. The reaction exhibits a broad substrate scope, tolerating aryl groups with diverse electronic properties, although slightly electron-deficient substrates afford higher efficiencies. Mechanistic studies support a radical pathway initiated by single-electron-transfer (SET) nitrosation of the enol form of the methyl aryl ketone.