I2/KI-Mediated Oxidative N-N Bond Formation for the Synthesis of 1,5-Fused 1,2,4-Triazoles from N-Aryl Amidines

An I-2/KI-mediated oxidative N-N bond formation reaction is described. This new and environmentally benign approach allows for the convenient synthesis of a variety of 1,2,4-triazolo [1,5-a]pyridines and other 1,5-fused 1,2,4-triazoles from readily available N-aryl amidines in an efficient and scalable fashion.