Palladium/Norbornene-Catalyzed ortho Aliphatic Acylation with Mixed Anhydride: Selectivity and Reactivity.

A palladium/norbornene-catalyzed ortho acylation for the efficient synthesis of functionalized alkyl aryl ketones is reported. Studies on the electronic and steric properties of mixed aryl anhydrides indicated that the cross-coupling favored with the electron-enriched aryl acyl group. DFT calculation on the oxidative addition of Pd(II) with 2,4,6-(Cl)3C6H2CO2C(O)Ph suggested that 2,4,6-(Cl)3C6H2C(O)-O bond cleavage was more kinetically disfavored than that of the PhC(O)-O bond by 11.7 kJ/mol.