Copper(<scp>ii</scp>)-mediated metalloradical activation: denitrogenative/decarboxylative annulation to 3-arylimidazo[1,2-<i>a</i>]pyridines using tetrazolo[1,5-<i>a</i>]pyridines and cinnamic acids

A new approach involving copper(II)-based metalloradical activation has been explored for the synthesis of diverse 3-arylimidazo[1,2-<i>a</i>]pyridines <i>via</i> denitrogenative/decarboxylative intermolecular annulation of tetrazolo[1,5-<i>a</i>]pyridines with cinnamic acids using trifluoroacetic acid and cesium carbonate in <i>p</i>-xylene. The reaction is facile and is assumed to proceed <i>via</i> a copper-nitrene species.