Upon thermolysis at 40-50" C, 5-(diazomethyl)-1, 4-diphenyl-1, 2, 3-triazole (1) reacts with p- ethyltoluene, p-cymene, p-tert-butyltoluene, p-diisopropylbenzene, durene, and naphthalene to give a mixture of carbene-derived cycloheptatriene/norcaradiene products; attack is favored adjacent to the more highly branched substituent. Decomposition of 1 in p- diisopropylbenzene afforded a tropilidene and a CH insertion product in a ca. 1: l ratio. ...