Photoinduced Intramolecular Cyclization of 9-(ω-Anilinoalkyl)phenanthrenes

Abstract

Photoreactions of a series of compounds of the type 9-phenanthryl–A–CH2NHC6H5[–A–=o-phenylene (1b), –(CH2)2– (1c), –(CH2)3– (1d), –(CH2)4– (1e), –CH2– (1f)] in benzene were studied. From 1b–d, the spiro compounds are obtained by an intramolecular cis-addition of the N–H function to the C9, C10-double bond of the phenanthrene ring. These photoproducts can be converted to the starting materials by treating with trifluoroacetic acid or heating above their melting temperatures. The mechanistic features of these reactions are described.

Formation of polycyclic compounds in the photoreactions of 9-(ω-anilinoalkyl)phenanthrenes

“…(2)]. 4 Here, we describe the photochemical reactions of 9-(o-anilinoalkyl)phenanthrenes 3 ( n = 6-10 and 12), which undergo cyclization of the anilino group with the 1,3-and 6,8-positions of the phenanthrene ring. Probable intermediates Compound 6.…”

Radical ion cyclizations

“…N-H addition to the phenanthrene C(9)-C(10) bond [216][217][218]. Recently, photolysis of 9-(6-anilinohexyl)phenanthrene 273 in benzene yielded an unexpected polycyclic product 274 which has a benzomorphan skeleton !-219].…”