- Photochemical studies on the through-space S···S interaction of 2- phenylnaphtho[1,8-de][1,3]dithiin 1-oxide, 5-phenyl[1]benzothieno[4,3,2- def][1,3]benzodithiepin 4-oxide, and 2-phenyldibenzo[d,f][1,3]dithiepin 1- oxide
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2-Phenylnaphtho[1,8-de][1,3]dithiin 1-oxide (4a), 5- phenyl[1]benzothieno[4,3,2-def][1,3]benzodithiepin 4-oxide (4b), and 2- phenyldibenzo[d,f][1,3]dithiepin 1-oxide (4c) underwent facile consecutive photochemical reactions to give the corresponding disulfide, naphtho[1,8- cd][1,2]dithiole (1a), [1]benzothieno[4,3,2-cde][1,2]benzodithiin (1b), and dibenzo[c,e][1,2]dithiin (1c) and benzaldehyde (7), respectively, via the sulfur-sulfur (S···S) interaction. The proposed mechanism for these photochemical reactions is based on the quantum yields measurements, photo- intensity effects, and sensitizer effects. Ab initio calculations were also carried out for a model compound of the primary photoproduct, which showed that the S···S distance becomes shorter and the S-O distance becomes longer upon the excitation to the S1 state.
- Fujii, Takayoshi,Kusanagi, Hiroki,Takahashi, Ohgi,Horn, Ernst,Furukawa, Naomichi
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p. 5027 - 5046
(2007/10/03)
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- Investigations on Benzothiirene
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Thermolysis and photolysis of 1,2,3-benzothiadiazole 10c furnish the products 11c - 15c. 13C-labelling experiments demonstrate that an intermediate benzothiirene 1c is not formed.Isotopomeric reaction products are due to H-shifts.Electron withdrawing ester groups in 6-position enable the ring closure to the substituted benzothiirenes 1d, e on the photochemical but not on the thermal route.A proof is given by an extensive study of the disulfides 14d, e, 14d', e', and 14d'', e'', generated in the thermolysis, photolysis and by an independent procedure.The results are based on 13C and 1H NMR measurements.Unequivocal signal correlations were made by deuterations and heteronuclear double resonances.
- Meier, Herbert,Konnerth, Ursula,Graw, Sylvia,Echter, Toni
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p. 107 - 126
(2007/10/02)
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- Reaction of 1,2,3-Benzothiadiazoles with Radicophilic Alkenes and Alkynes in Di-tert-butyl Peroxide.
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The reaction of 6-X-1,2,3-benzothiadiazoles (1) with the radicophilic alkenes 1,1-diphenylethylene (2) and 1-cyano-1-(tert-butylthio)ethylene (3) and the alkynes PhCCR (4, R=H or Ph) in di-tert-butyl peroxide (TBP) leads to the cycloadducts 5, 7, and 8.The proposed mechanism involves an initial attack by tert-butoxy radical at the sulfur atom of 1 affording the radical intermediate 9 which is responsible for the formation of all the reaction products.
- Albertazzi, A.,Leardini, R.,Pedulli, G.F.,Tundo, A.,Zanardi, G.
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p. 4482 - 4486
(2007/10/02)
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- Thermal Reactions of Aryl Azides with 1,2,3-Benzothiadiazole
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Thermolysis of phenyl azide in the presence of 1,2,3-benzothiadiazole (1) affords phenothiazine (2), thianthrene (3), and dibenzo-o-dithiin (4) together with aniline and traces of azobenzene, while p-nitrophenyl azide gives no phenothiazine derivative and decreased yields of (3) and (4), whereas increased yields of (3) and (4) are observed with p-methoxyphenyl azide, together with small amounts of the phenothiazine derivative; evidence in favour of an initial attack on the sulphur of (1) by triplet arylnitrenes is presented.
- Benati, Luisa,Montevecchi, P. Carlo,Spagnolo, Piero
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p. 715 - 717
(2007/10/02)
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