Synthesis of 2-aminopyridines via ruthenium-catalyzed [2+2+2] cycloaddition of 1,6- and 1,7-diynes with cyanamides: scope and limitations

A direct route to access 2-aminopyridines using Ru-catalyzed-[2+2+2] cycloaddition of 1,n-diynes with cyanamides is described in excellent yields and regioselectivities.