Pd/C-catalyzed synthesis of N-aryl and N-alkyl isoquinolones via C[sbnd]H/N[sbnd]H activation

Abstract

Pd/C-catalyzed direct synthesis of N-aryl and N-alkyl isoquinolones was developed via the annulation reactions of benzamides and alkynes in high yields (up to 99%) through the cleavage of CH/NH bonds. The reaction was ligand-free and air was used as oxidant. High regioselectivities were found when unsymmetrical alkynes or meta-benzamides were used as substrates. The heterocyclic carboxamide substrates, such as furan and thiophene derivatives, also afforded the corresponding products in high yields.