- Synthesis, structure, and chemistry of new, mixed group 14 and 16 heterocycles: Nucleophile-induced ring contraction of mesocyclic dications
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More than 40 new 4- to 12-membered ring heterocycles containing various combinations of Group 14 and 16 elements Si, Sn, S, Se, and Te have been synthesized and fully characterized. Synthesis of these small-ring as well as medium-ring (mesocyclic) heterocycles from α,ω-dihalides is facilitated by the presence of gem-dialkylsilyl and gem-dialkylstannyl groups in the precursors. Conformations of several of the new ring systems in the solid state have been determined by X-ray crystal structure analysis. Oxidation of mixed S(Se, Te)/Si eight-membered ring mesocycles with NOPF6 or Br2 gives dications or a bicyclic dibromide, respectively, which can be characterized by NMR methods. On treatment with nucleophiles, mesocyclic dications, or the corresponding radical cations undergo ring contraction, giving five- or six-membered ring heterocycles. Photolysis of a S/Se four-membered ring heterocycle gives selenoformaldehyde, trapped in 80% yield with 2,3-dimethyl-1,3-butadiene.
- Block, Eric,Dikarev, Evgeny V.,Glass, Richard S.,Jin, Jin,Li, Bo,Li, Xiaojie,Zhang, Shao-Zhong
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- Preparation of ω-tetrahydropyran-2-ylsulfanylalkylmagnesium chlorides: Useful reagents for the synthesis of 1-(ω-mercaptoalkyl)-1,2- dihydrobuckminsterfullerenes (C60)
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ω-Tetrahydropyran-2-ylsulfanylalkylmagnesium chlorides are prepared as Grignard reagents containing protected mercaptoalkyl chains, which are useful for the direct introduction of ω-mercaptoalkyl chains to electrophiles. In order to prove the usefulness of these reagents, they were reacted with buckminsterfullerene (C60) to give 1-(ω-mercaptoalkyl)-1,2- dihydrobuckminsterfullerenes after the deprotection of THP group with TFA.
- Kim, Sung Hoon,Lee, Sung Han,Kang, Seung Hoon
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- A general and mild synthesis of thioesters and thiols from halides
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The conversion of a wide variety of halides to thioesters by reaction with potassium thiocetate under mild conditions is described, and the generality of the method is demonstrated.
- Zheng, Tu-Cai,Burkart, Maureen,Richardson, David E.
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p. 603 - 606
(2007/10/03)
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