A simple and efficient approach has been developed for the synthesis of imidazo[1,5-a]pyridines using the elemental sulfur mediated sequential dual oxidative Csp3–H amination of 2-pyridyl acetates and amines under metal- and peroxide-free conditions. Broad substrate scope, operational simplicity and gram-scale ability make this chemistry very practical.
![Graphical abstract: Metal-free synthesis of imidazo[1,5-a]pyridines via elemental sulfur mediated sequential dual oxidative Csp3–H amination](http://hg.y866.cn/compound/lib/scimg/usr/1/C8OB01391H.jpg)