Palladium catalyzed carbonylative annulation of the C(sp<sup>2</sup>)–H bond of <i>N</i>,1-diaryl-1<i>H</i>-tetrazol-5-amines and <i>N</i>,4-diaryl-4<i>H</i>-triazol-3-amines to quinazolinones
as both directing as well as intramolecular nucleophiles. The catalytically active C–H activated intermediate dimeric Pd complex was isolated and characterized which on exposure to CO gas gave the corresponding tetrazole fused quinazolinone derivative. On the basis of isolation of the intermediate and observed kinetic isotope effects, a mechanism has been proposed for the C–H activated direct carbonylative