Intramolecular nitrene insertions into aromatic and heteroaromatic systems. Part 4. Insertions using triphenylmethanes, unactivated or bearing electron-donating groups

Abstract

Thermal decompositions of the o-azidotriphenylmethanes (5), (6), (11), and (12) have given 9-phenylacridans, 9-phenylacridines, and 11-phenyl-10H-azepino[1,2-a]indoles. From azides (6) and (11) the tetracyclic compounds (21) and (30) were also obtained. Photolytic decomposition of azides (5) and (6), and thermolysis of azide (5) at different temperatures and in various solvents leads to the suggestion that acridans and acridines are derived from triplet nitrene, while azepinoindoles and tetracyclic compounds (21) and (3) are derived from singlet nitrene. Further transformations of compounds (21) and (30) have given 11-arylazepino[1,2-a]indol-8-one (24) and dihydroazepinoindolones (20) and (31). Decomposition of o-azidodiphenyl[²H₂]methane (40) gave [10,11-²H₂]azepino[1,2-a]indole (41).