- SYNTHESIS, STRUCTURE, AND CHEMICAL PROPERTIES OF TRIMETHYLSILYL DERIVATIVES OF THIOLACTAMS
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Trimethylsilyl derivatives of five-, six-, and seven-membered thiolactams with an N-silyl structure were synthesized for the first time.Their alkylation with primary alkyl halides under comparatively mild conditions occurs at the sulfur atom; the reaction with secondary alkyl halides is accompanied by hydrogen halide elimination, and this becomes the only reaction pathway with tertiary halides.The preparative acylation of N-trimethylsilylthiolactams yields N-acyl derivatives; the intermediate formation of S-acylation products was established by means of low-temperature NMR monitoring.
- Sergeev, V. N.,Artamkin, S. A.,Pestunovich, S. V.,Albanov, A. I.,Voronkov, M. G.,Baukov, Yu. I.
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p. 1490 - 1497
(2007/10/02)
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- A New Synthesis of β-Lactams via Photochemical γ-Hydrogen Abstraction of Monothioimides
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Photochemical reactions of acyclic and semicyclic monothioimides were studied.Photolysis of acyclic monothioimides gave β-lactams (Type II cyclization products) and thioamides (Type II cleavage products). 4-Mercapto-β-lactams were isolated as 4-acylthio-β-lactams by acylation with benzoyl chloride or acetyl chloride in the presence of triethylamine.Irradation of six- or seven- membered semicyclic monothioimides gave bicyclic β-lactams, but five-membered semicyclic monothioimides gave only Type II cleavage products.
- Sakamoto, Masami,Watanabe, Shoji,Fujita, Tsutomu,Tohnishi, Masakazu,Aoyama, Hiromu,Omote, Yoshimori
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p. 2203 - 2208
(2007/10/02)
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- Studies on organophosphorus compounds. XLV. Thiation of some sterically hindered N-nitrosamides
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Some sterically hindered N-nitrosamides have been prepared using sodium nitrite in aqueous acid solution.Reaction of these N-nitrosamides with 2,4-bis-(4-methoxyphenyl)-1,2,3,4-dithiadiphosphetane-2,4-disulfide (Lawesson's Reagent ) causes thiation of both the carbonyl and the nitroso groups followed by destruction of the nitroso group giving ultimately the corresponding thioamides and amides as the main products.Dihydro-2(3H)-thiophenone is isolated as a by-product when N-nitroso-dihydro-2(3H)-pyrrolidinone is reacted with LR.A mechanism for its formation is postulated.Thiation of the sterically hindered amides yields the thioamide as rotamers which in two cases could be separated by column chromatography.Ames test has been performed for some of the compounds.
- Joergensen, Karl Anker,Ghattas, Abdul-Badik,Lawesson, Sven-Olov
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p. 204 - 208
(2007/10/02)
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