- Polycyclic fused phenanthridines: An alternative approach from benzotriazoles
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We describe an alternative approach to polycyclic phenanthridines (7) and some of their analogues using conditions much milder than those previously reported. The procedure includes the generation of a benzotriazole stabilized carbanion, oxidation of the resulting anion to a radical, and elimination of nitrogen followed by ring closure to produce phenanthridines.
- Katritzky, Alan R.,Du, Weihong,Matsukawa, Yasuhisa,Ghiviriga, Ion,Denisenko, Sergey N.
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- An aryl to imidoyl palladium migration process involving intramolecular C-H activation
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Biologically interesting fluoren-9-one and xanthen-9-one derivatives have been prepared by a novel aryl to imidoyl palladium migration, followed by intramolecular arylation. The fluoren-9-one synthesis appears to involve both a palladium migration mechanism and a C-H activation process proceeding through an unprecedented organopalladium(IV) hydride intermediate. The results from deuterium labeling experiments are consistent with the proposed dual mechanism.
- Zhao, Jian,Yue, Dawei,Campo, Marino A.,Larock, Richard C.
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p. 5288 - 5295
(2008/02/02)
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- The thermal and photolytic decomposition of 9-aryl-9-xanthenyl azides to 11-aryldibenzo[b,f][1,4] oxazepines
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In contrast to the different ratios of products obtained in the thermal decomposition of some 9-aryl-9-xanthenyl azides, it was found that photolysis afforded the same product ratio. The mechanism of these reactions is discussed in terms of intermediates as well as conformational and electronic effects in the transition states.
- Coombes, Philip,Goosen, Andre,Taljaard, Benjamin
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p. 559 - 563
(2007/10/02)
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- Extremely Reactive C=C Double Bonds, VI. - Tris(methylphenylamino)methane - The Chemistry of Orthoamides
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Reactions of the title compound 2 with sulfur, selenium, thiophenol, malononitrile, 1,3-indanedione, fluorenone hydrazone, phenylmagnesium bromide, bromine, thioacetic acid, N,N'-diphenylurea, oxalyl chloride, 9,9-dichloroxanthene, phenyl isocyanate, and stilbene dibromide are described and the mechanisms are discussed.The catalytic influence of 2 on the decomposition of 9-diazofluorene in xylene and mesitylene is discussed.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner
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p. 1581 - 1588
(2007/10/02)
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- C = C Double Bonds with Extreme Reactivity, III. Reactions of 9-(9-Fluorenylidene)xanthene
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According to equations (1) to (4), 9-(9-fluorenylidene)xanthene (2) reacts with sulfur, malonodinitrile, aniline, or thiophenol to give the compounds 3, 5, 7-11, and diphenyl disulfide.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner
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p. 3762 - 3765
(2007/10/02)
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- EXTREMELY REACTIVE CARBON-CARBON DOUBLE BONDS-I; REACTIONS WITH 2-(9-XANTHYLIDENE)-, 2-(9-THIOXANTHYLIDENE)-, AND 2-(9-FLUORENYLIDENE)-INDANE-1,3-DIONE. A CONTRIBUTION ON THE STRUCTURE AND REACTIVITY OF NON-PLANAR C-C DOUBLE BONDS
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The compounds in the title (cf 1a, 1b and 2) react with various reagents, often under mild conditions, mostly by breaking of the central double bond.According to X-ray diffraction the central double bond of 2-(9-xanthylidene)indane-1,3-dione is inclined by 47.2 deg.The relationship between the structure and reactivity of the compounds in the title is discussed.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner,Sheldrick, William S.
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p. 2429 - 2438
(2007/10/02)
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- Keten. Part 17. Addition Reactions of Ketens with N-Phenyl Nitrones
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The N-phenyl nitrones (1a), (4b), and (15) react with ketens in two totally different ways.Triphenylnitrone (4b) forms oxidolones (6) whereas (1a) and (15) form oxazolidinones (2) and (17).The differences appear to be caused by steric interactions in (1a) and (15) which distort the nitrone function and prevent the N-phenyl group adopting the conformation necessary for the oxindole-forming pathway.
- Hafiz, Mushtag,Taylor, Giles A.
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p. 1700 - 1705
(2007/10/02)
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