Ruthenium-Catalyzed, Microwave-Mediated [2+2+2] Cycloaddition: A Useful Combination for the Synthesis of 2-Aminopyridines

A ruthenium-catalyzed [2+2+2] cycloaddition between alpha,omega-diynes and cyanamides is reported under microwave irradiation to access 2-aminopyridines. In contrast to the classical thermal conditions, this atom-economical sustainable protocol allows access to diverse functionalized 2-aminopyridine derivatives with high yields and excellent regioselectivities in MeTHF with short reaction times.