Indoles, oxygenated, radicals from

The anion-radical mechanism for these syntheses is based on the following facts. The reactions require photo- or electrochemical initiation. Oxygen inhibits the reactions totally, even with photoirradiation. Indoles are formed from o-iodoaniline only the meta isomer does not give rise to indole. Hence, the alternative aryne mechanism (cine-substitution) is not valid. What remains as a question is the validity of the ion-radical mechanism exclusively to the substitution of the acetonyl group for the halogen atom in o-haloareneamine or also for intramolecular condensation. 

Sevilla MD, Becker D, Mengyayo Y (1990b) Structure and reactivity of peroxyl and sulphoxyl radicals from measurement of oxygen-17 hyperfine couplings relationship with Taft substituent parameters. J Chem Soc Faraday Trans 86 3279-3286 Shen X, Lind J, Eriksen TE, Merenyi G (1989) The reaction of the CCI3O2 radical with indoles. J Chem Soc Perkin Trans 2 555-562... 

Many pyridine-indole compounds are biologically active. A growing number of methods for the preparation of indolylstannanes have been developed. 2-Trialkylstannylindoles, for example, have been synthesized via directed metalation followed by reaction with tin chloride [91-93]. The latest indolylstannane syntheses include Fukuyama s free radical approach to 2-trialkylstannylindoles from novel isonitrile-alkenes [94], and its extension to an isonitrile-alkyne cascade [95]. Assisted by the chelating effect of the SEM group oxygen atom, direct metalation of 1-SEM-indole and transmetalation with BujSnCl afforded 2-(tributylstannyl)-l//-indole 108, which was then coupled with 2,6-dibromopyridine to give adduct 109. 

Martinez GR, Medeiros MHG, Ravanat J-L, Cadet J, Di Mascio P (2002) [0ls]-Labeled singlet oxygen as a tool for mechanistic studies of 8-oxo-7,8-dihydroguanine oxidative damage detection of spiroiminodihydantoin, imidazolone and oxazolone derivatives. Biol Chem 383 607-617 Martini M, Termini J (1997) Peroxy radical oxidation of thymidine. Chem Res Toxicol 10 234-241 Merenyi G, Lind J, Shen X (1988) Electron transfer from indoles, phenol, and sulfite (S032T to chlorine dioxide (CICV). J Phys Chem 92 134-137... 

A time-resolved study of the decay kinetics of transient radicals produced from 2,2,4,6-tetramethyl-l,2-dihydroquinoIine in both aqueous and micellar solution has appeared, and sanguinarine, a benzophenanthridine plant alkaloid, has been photooxidised to oxysanguinarine in an irreversible singlet state process. Pyrrolo-[2,3-b]indole (77) has been produced with some enantioselectivity by photosensitized oxygenation of Nb-(methoxycarbonyl)tryptamine in the presence of (-)-nicotine, and irradiation of 3-methylindole on a CdS surface and under... 

The [Ir(ppy)2bpy] complex photo-catalyses inter- and intramolecular C-H functionalisation reactions of tertiary amines under the visible light irradiation. Oxygen behaves as a chemical switch, triggering different reaction pathways and leading to different products from the same starting material. In anaerobic conditions, the intermolecular addition of iV,iV-dimethyl-anilines to electron-deficient alkenes yields y-amino nitriles. Aerobic conditions, on the other hand, favour a radical addition/ cyclisation reaction, leading to tetrahydroquinoline derivatives. The intramolecular version of the radical addition produces unexpectedly indole-3-carboxaldehyde derivatives. ... 

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