The Barbier–Grignard‐Type Arylation of Ketones and Unexpected Cross‐Coupling of Phenolic Ketones using Unactivated Aryl Bromides

Abstract A novel, highly versatile and efficient method has been developed for the Barbier–Grignard‐type arylation of ketones and an unexpected cross‐coupling of phenolic ketones was observed using unactivated bromides and magnesium in tetrahydrofuran/toluene at 96 °C promoted by multicatalysts of cupric bromide (15 mol%), bismuth chloride (5 mol%) and silver bromide (10 mol%). The substituent and electronic effects on the reaction have been discussed. High yields of arylation and cross‐coupling have been attained under mild conditions. A novel reasonable mechanism involving a quinone intermediate is proposed. The high chemical selectivity in the cross‐coupling to the hydroxy group of phenolic ketones should help ketones find new applications. magnified image