Roger J. Hayward

Photocyclization reactions of aryl polyenes—VI: The photocyclization of 1,4-diaryl-1,3-butadienes

Abstract Calculations by the Simple Huckel Molecular Orbital (SHMO) method of the sum of the free valence indices in the first excited state (ΣF*) of the terminal atoms concerned in the photocyclizations of 1,4-diaryl-1,3-butadienes give values which are accurate guides in predicting the photoproducts obtained in the photocyclization-oxidation reactions of 1,4-diaryl-1,3-butadienes. Irradiation of 1,4-di-α-naphthyl-1,3-butadiene gave 1-α-naphthylphenanthrene. The photocyclization-oxidation of 1,4-di-β-naphthyl-1,3-butadiene gave a mixture of 4-β-naphthylphenanthrene and naphtho[1,2-e]pyrene. It was shown that the naphtho[1,2-e]pyrene arose from a subsequent photocyclization-oxidation reaction of the first-formed 4-β-naphthylphenanthrene. Irradiation of 1-α-naphthyl-4-β-naphthyl-1,3-butadiene gave 4-α-naphthylphenanthrene. The structures of the photoproducts were confirmed by independent syntheses. All the photoproducts obtained from the irradiation of 1,4-diaryl-1,3-butadienes were the ones predicted by the SHMO calculations.

Photocyclization reactions of aryl polyenes—II: The photocyclization of 1-aryl-4-phenyl-1,3-butadienes

Abstract The photocyclization-oxidation reaction of 1-(β-naphthyl)-4-phenyl-1,3-butadiene gave 4-phenylphenanthrene and 1,2-benzopyrene. It was shown, however, that the 1,2-benzopyrene arose from a subsequent photochemical reaction of the first-formed 4-phenylphenanthrene. Irradiation of 1-(9′-phenanthryl)-4-phenyl-1,3-butadiene gave 1-phenyltriphenylene. The photocyclization-oxidation of 1-(9′-anthryl)-4-phenyl-1,3-butadiene yielded 3,4,8,9-dibenzopyrene. The formation of 3,4,8,9-dibenzopyrene is postulated to involve the intermediacy of a benzo-[10]-annulene.

N-bridged heterocycles. Part I. Synthesis and chemistry of NN′-polymethylene-o-phenylenediamines

Methods have been eleborated for the synthesis of the series of NN′-polymethylene-o-phenylenediamines with 5–10 and 12 methylene groups. The interaction of these compounds with formaldehyde, benzaldehyde, and other aldehydes (to give bridged 2,3-dihydro-1H-benzimidazoles), with di-acid chlorides such as phosgene, thiophosgene, and oxalyl, succinyl, and sebacoyl chloride (to give various bridged heterocycles), with heterocumulenes such as carbon disulphide, and phenyl isocyanate and isothiocyanate, and with oxidising agents are reported.

Photocyclization Reactions of Aryl Polyenes - III. The Photocyclization of 1,8-Diphenyl-1,3,5,7-octatetraene and 1,10-Diphenyl-1,3,5,7,9- decapentaene

Abstract The photocylization-oxidation reaction of 1,8-diphenyl-1,3,5,7-octatetraene gave 1-phenylphenanthrene and a trace of 9-phenylphenanthrene. It was shown that 1-(α-naphthyl)-4-phenyl-1,3-butadiene and o -phenylstilbene may be intermediates in the formation of the photoproducts of 1,8-diphenyl-1,3,5,7-octatetraene. The irradiation of 1,10-diphenyl-1,3,5,7,9-decapentaene yields picene. It was demonstrated that 1-(α-naphthyl)-6-phenyl-1,3,5-hexatriene, 1,2-di-(α-naphthyl)ethylene, and 1-styrylphenanthrene are likely intermediates involved in the formation of picene.

N-bridged heterocycles. Part II. Synthesis and aromaticity of 1,3-polymethylene-benzimidazolium salts {[n](1,3)benzimidazolophanium salts}, -benzimidazolones, and -benzimidazolethiones

[n](1,3)Benzimidazolophanium salts have been synthesised from NN′-polymethylene-o-phenylenediamines with 6–12 methylene groups in the bridge, by the action of dichloromethyl methyl ether. The aromaticity of this series of compounds is compared to that of the corresponding series of benzimidazol-ones and -thiones with 5–12 bridging methylene groups by a study of their u.v., i.r., and 1H and 13C n.m.r. spectra. It is concluded that aromaticity is significant in the salts with n 6, in the bridged benzimidazolones with n 7, and in the bridged benzimidazolethiones with n 7 or 8.