3-Diazo-2, 5-diphenylpyrrole (1) thermolyzes and photolyzes to 2, 5-diphenyl-3H- pyrrolylidene (3)) which inserts into methylene hydrogen of cyclohexane and methyne hydrogen of cumene. Hydrogen abstraction to give 2, 5-diphenylpyrrole (7) occurs competitively in these systems. Carbene 3 reacts with cyclohexene, allylbenzene, and 2, 3- dimethyl-2-butene to give 3-(allylically substituted)-2, 5-diphenylpyrroles (15, 20, 21, and ...