Palladium–imidazolium-catalyzed carbonylative coupling of aryl diazonium ions and aryl boronic acids

Palladium(II) acetate and N,N-bis-(2,6-diisopropylphenyl)dihydroimidazolium chloride (2 mol%) were used to catalyze the carbonylative coupling of aryl diazonium tetrafluoroborate salts and aryl boronic acids to form aryl ketones. Optimal conditions include carbon monoxide (1 atm) in 1,4-dioxane at 100°C for 5 h. Yields for unsymmetrical aryl ketones ranged from 76 to 90% for isolated materials with only minor amounts of biaryl coupling product observed (2–12%).