Photosensitized synthesis of phenanthrene heterocycles from 1- and 9-(aminoalkyl)phenanthrenes

✍ Scribed by Frederick D. Lewis; G.Dasharatha Reddy; Bliss E. Cohen

• Publisher: Elsevier Science
• Year: 1994
• Tongue: French
• Weight: 327 KB
• Volume: 35
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)75831-x

✦ Synopsis

77~ photosensitized electron transfer reactions of several I-and 9-(aminoalkyf)phenanthrenes with metadicyanobenzene have been investigated.

These reactions provkie an effldent method of synthesis for the skeletal structures of the apcrphlne, phenantfwpipefM?e, and phenanthnxzephw alkabids.

Photoamination

of aromatic molecules with amines attached via an alkyl chain provides an efficient synthetic route to heterocyclic compounds. t,* Previous work in our laboratory demonstrated that under direct irradiation orII?o-((N-methylamino)alkyl)stilbenes cyclize to form benzazepines*e and a-and j%((N-methylamino)alkyl)styrenes cyclize to form piperidine and pyrrolidine adducts.*bl*c Sugimoto and co-workers' have reported that irradiation of 9-(anilinoalkyl)phenanthrenes results in N-H addition to the phenanthrene 9,lO bond. The initial step in these reactions, electron transfer from ground state amine to singlet arene, is followed by N-H proton transfer and biradical cyclization.