- Thermolysis of selenophene 1,1-dioxides
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Selenophene 1,1-dioxides are thermally far labile than the corresponding thiophene 1,1-dioxides. Even heavily substituted tetraphenylselenophene 1,1-dioxide (1a) decomposed, by a process not involving cyclodimerization, when heated above its melting point or heated in refluxing toluene. Thus, the thermolysis of la in refluxing toluene afforded tetraphenylselenophene (2a, 6%), tetraphenylfuran (3a, 71%), (Z)-l,2,3,4-tetraphenyl-2-butene-l,4-dione (Z-4a, 19%), (E)-1,2,3,4-tetraphenyl-2-butene-1,4-dione (E-4a, 4%), SeO2 (23%), and Se (22%), while that of the neat sample gave 2a (5%), Z-4a (78%), E-4a (17%), SeO2 (17%), and Se (29%). Similar results were also obtained on thermolyses of a series of selenophene 1,1-dioxides. The experimental observations (influence of solvents, oxygen, and additive such as diene to the decomposition rate and the presence of induction period) revealed that the mechanism of the decomposition is highly complex. A tentative mechanism that can explain the observed products is presented.
- Umezawa, Takashi,Matsui, Tomoki,Sugihara, Yoshiaki,Ishii, Akihiko,Nakayama, Juzo
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- Oxidation of Aromatic Compounds. IV. Oxidation of Symmetrical Diarylacetylenes in the CF3COOH-CH2Cl2-PbO2 System. A New One-Pot Synthesis of 1,2,3,4-Tetraaryl-2-butene-1,4-diones
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Oxidation of symmetrical diarylacetylenes in the CF3COOH-CH2Cl2-PbO2 system (0-20 deg C, 1-3 h) yields 1,2,3,4-tetraaryl-2-butene-1,4-diones.According to (1)H NMR and GC-MS data the compounds synthesized have Z configuration.
- Rudenko, A. P.,Vasil'ev, A. V.
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p. 1360 - 1379
(2007/10/03)
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- Oxidation of Tetraarylselenophenes and Benzoselenophene with m-Chloroperbenzoic Acid
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Oxidation of tetraarylselenophenes with m-chloroperbenzoic acid produces cis-1,2-diaroyl-1,2-diarylethylenes and SeO2 as the principal product, while the oxidation of benzoselenophene affords benzoselenophene 1-oxide.
- Nakayama, Juzo,Matsui, Tomoki,Sato, Noriko
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p. 485 - 486
(2007/10/03)
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