Csp2-N Bond Formation via Ligand-Free Pd-Catalyzed Oxidative Coupling Reaction of N-Tosylhydrazones and Indole Derivatives
Résumé
In a fresh approach to the synthesis of N-vinylazoles, a ligand-free palladium catalytic system was found to promote the Csp2-N bond-forming reaction utilizing N-tosylhydrazones and N-H azoles. This process shows functional group tolerance, di-, tri- and tetrasubstituted N-vinylazoles were obtained in high yields. Under the optimized conditions, the reaction proceeds with high stereoselectivity depending on the nature of the coupling partners