Syntheses of Benzo[c]Chromen-6-ones by Palladium Catalyzed C–H Bond Activation using Diazonium Salts

Abstract

An efficient palladium catalyzed C−H bond activation for the synthesis of benzo[c]chromen-6-ones using diazonium salts is described. In the presence of Pd(OAc) 2 , dppp, PivOH and K 2 CO 3 , the diazonium salt can be transformed into the product through a denitrogenation/C−H bond activation/cyclization sequence in acetonitrile. Altogether, nine structurally diverse substituted benzo[c]chromen-6-ones were prepared in excellent yields through two different methods.