ortho-Benzoxylation of N-alkyl benzamides with aromatic acids catalyzed by ruthenium(II) complex

Abstract

A highly regioselective ortho-benzoxylation of N-alkyl benzamides with aromatic acids in the presence of [{RuCl2(p-cymene)}2], AgSbF6 , and (NH4)2S2O8 in 1,2-dichloroethane at 100 °C for 24 h affording ortho-benzoxylated N-alkyl benzamides by C-H bond activation is described. Further, Ru-catalyzed alkenylation is done at the ortho C-H bond of benzoxylated N-alkyl benzamides with alkenes in water solvent. Subsequently, the benzoxyl moiety of N-alkyl benzamides was converted into a hydroxyl group in the presence of base or acid. A possible reaction mechanism was proposed to account for the present coupling reaction.

Keywords: CH activation; alkenylation; amides; benzoxylation; hydroxylation; ruthenium.