Regioselective Cobalt-Catalyzed Formation of Bicyclic 3-and 4-Aminopyridines

Bimolecular cobalt-catalyzed [2 + 2 + 2] cycloadditions between yne-ynamides and nitriles afford bicyclic 3- or 4-aminopyridines in up to 100% yield. The high regioselectivity observed depends on the substitution pattern at the starting ynamide. Aminopyridines bearing TMS and Ts groups are efficiently deprotected in an orthogonal fashion.