917-54-4Relevant articles and documents
Di- and Tri-valent Complexes of Ytterbium via Novel Metal Oxidation
Watson, Patricia L.
, p. 652 - 653 (1980)
Oxidation of Yb metal by iodopentamethylcyclopentadiene (IC5Me5) afforded Li and Li sequentially in the presence of LiI; analogous anionic chloride complexes, the new divalent complex Yb(C5Me5)2, and methyl derivatives of both d
Synthesis of 8-alkylthio- and 8-selanyl-3-tert-butylpyrazolo[5,1-c][1,2,4]triazines
Ivanov, Sergey M.,Minyaev, Mikhail E.,Mironovich, Lyudmila M.
, p. 666 - 676 (2020)
Interaction of 8-lithio-3-tert-butyl-4-oxopyrazolo[5,1-c][1,2,4]triazin-1-ide with elemental sulfur or selenium in THF with further in situ alkylation at –97 °C followed by warming to room temperature furnished a series of 3-tert-butyl-8-X-pyrazolo[5,1-c][1,2,4]triazin-4(6H)-ones (X = n-BuS, n-BuSe, MeSe, PhCH2S) in good yields. 8,8'-Diselanediylbis(3-tert-butylpyrazolo[5,1-c][1,2,4]triazin-4(1H)-one) was also isolated as a by-product in these reactions. One-pot interaction of the n-BuSe substituted derivative with diborane/boron trifluoride led to reduction of the 1,2,4-triazine core and partial elimination of the alkylselanyl moiety. The structures of the synthesized products were established on the basis of IR, 1H, 13C, 2D HMBC 1H–77Se NMR and high resolution mass spectra, as well as X-ray single crystal diffraction analyses. Two of the prepared compounds were also tested for antimicrobial and antifungal activities.
Preparation and Crystal Structure of the Addition Compound MeLi*U4, a Compound with a Uranium to Carbon ?-Bond
Stewart, Joanne L.,Andersen, Richard A.
, p. 1846 - 1847 (1987)
Reaction of MeLi and U4 gives the additioncompound, LiU(Me)4 which in the solid state has a geometry based upon square pyramidal uranium with the apical site occupied by a methyl group and the four basal sites being occupied by oxygen atoms of the alkoxide ligand, two of which form bridges to the lithium atom.
A new strategy for the synthesis of organosilicon compounds of cyclopropane derivatives
Gholizadeh, Saeed,Safa, Kazem D.,Pesyan, Nader Noroozi
, p. 245 - 251 (2020/11/10)
The one-pot reaction of tetra-substituted cyclopropyl benzyl bromide with tris(trimethylsilyl)methyllithium (TsiLi) and carbon disulfide resulted in 3-(4-((((trimethylsilyl)ethynyl)thio)methyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (3) and 3-(4-((trimethylsilyl)methyl)phenyl)cyclopropane-1,2-dicarbonitrile (4) in excellent yield. The reaction in the absence of carbon disulfide yielded 3-(4-(2,2,2-tris(trimethylsilyl)ethyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (5) in excellent yield at 08C to room temperature. All structures were characterised by IR, 1H NMR, and 13C NMR spectroscopies. The reaction mechanisms are discussed.
Elongated Gilman cuprates: The key to different reactivities of cyano- and iodocuprates
Neumeier, Maria,Gschwind, Ruth M.
, p. 5765 - 5772 (2014/05/06)
In the past the long-standing and very controversial discussion about a special reactivity of cyano- versus iodocuprates concentrated on the existence of higher-order cuprate structures. Later on numerous structural investigations proved the structural equivalence of iodo and cyano Gilman cuprates and their subsequential intermediates. For dimethylcuprates similar reactivities were also shown. However, the reports about higher reactivities of cyanocuprates survived obstinately in many synthetic working groups. In this study we present an alternative structural difference between cyano- and iodocuprates, which is in agreement with the results of both sides. The key is the potential incorporation of alkyl copper in iodo but not in cyano Gilman cuprates during the reaction. In the example of cuprates with a highly soluble substituent (R = Me 3SiCH2) we show that in the case of iodocuprates during the reaction several copper-rich complexes are formed, which consume additional iodocuprate and provide lower reactivities. To confirm this, a variety of highly soluble copper-rich complexes were synthesized, and their molecular formulas, the position of the equilibriums, their monomers and their aggregation trends were investigated by NMR spectroscopic methods revealing extended iodo Gilman cuprates. In addition, the effect of these copper-rich complexes on the yields of cross-coupling reactions with an alkyl halide was tested, resulting in reduced yields for iodocuprates. Thus, this study gives an explanation for the thus far confusing results of both similar and different reactivities of cyano- and iodocuprates. In the case of small substituents the produced alkyl copper precipitates and similar reactivities are observed. However, iodocuprates with large substituents are able to incorporate alkyl copper units. The resulting copper-rich species have less polarized alkyl groups, i.e. gradually reduced reactivities.
Functionalized α-bromocyclopropylmagnesium bromides: Generation and some reactions
Bolesov,Solov'eva,Baird
, p. 1580 - 1589 (2014/02/14)
Functional derivatives of gem-dibromocyclopropanes (ethers and esters of gemdibromocyclopropylmethanol, 2,2-dibromocyclopropanecarboxylic acids and their esters) undergo partial hydrodebromination at the treatment with isopropyl magnesium bromide (3-6 mol-equiv) in THF and then in methanol at -60°C affording the corresponding monobromides in 64-95% yields. The addition of nonsolvated magnesium bromide to the reaction mixture results in the considerable reduction of the amount of the Grignard reagent (from 6 to 3 mol-equiv). This allows achieving the partial hydrodebromination of 2,2-dibromocyclopropanecarboxylic acids. Pleiades Publishing, Ltd., 2013.
Synthesis agent containing methyllithium/lithium bromide and processes for its preparation
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Page/Page column 6, (2008/06/13)
Methyl lithium and lithium bromide containing synthetic agent (A) comprises a solvent (I), where the methyl lithium and lithium bromide are dissolved and the molar ratio of lithium bromide to methyl lithium is at least 0.7 and maximum 1.5. Methyl lithium and lithium bromide containing synthetic agent (A) comprises a solvent (I) of formula C(R 1>)(R 2>)(OR 3>)(OR 4>), where the methyl lithium and lithium bromide are dissolved and the molar ratio of lithium bromide to methyl lithium is at least 0.7 and maximum 1.5. R 1>, R 2>H, CH 3 or CH 2CH 3; and R 3>, R 4>CH 3 or CH 2CH 3. Independent claims are also included for the preparations of (A).
The cocondensation reaction of lithium atoms and anisole: An experimental and theoretical study of the reaction pathway
Mendoza, Oscar,Cuffe, Laurence P.,Rehmann, Franz-Josef K.,Tacke, Matthias
, p. 1511 - 1522 (2007/10/03)
The cocondensation reaction of lithium atoms and pure anisole leads to an ortho CH activation and the formation of lithium hydride. This simple two-component system allows the investigation of the reaction mechanism with included donor molecules. Therefore two anisole and one dilithium molecule, which was identified in an earlier spectroscopic study, were considered for the reaction pathway calculations. Firstly, two intermediates can be found along the reaction pathway, which show the reaction before and after the critical CH activation step. Secondly, a low-lying transition state can be identified, which allows the carbon hydrogen bond to be broken with an activation energy of less than 20 kcal/mol instead of more than 100 kcal/mol, if a free radical mechanism is employed. All calculations were performed at the B3LYP/6-31G** level of theory.
Lithium-2-2'-biphenyldiyltrimethylsilicat: erstmalige Beobachtung von Pentaorganosilicaten
Keijzer, Adrianus H. J. F. de,Kanter, Franciscus J. J. de,Schakel, Marius,Schmitz, Robert F.,Klumpp, Gerhard W.
, p. 1183 - 1184 (2007/10/03)
Keywords: Lithiumverbindungen; NMR-Spektroskopie; Siliciumverbindungen; Substitutionen
Diastereoselective Addition of Organometallics to N-(α-Ketoacyl)-trans-2,5-bis(methoxymethoxymethyl)pyrrolidine
Kawanami, Yasuhiro,Fujita, Izumi,Ogawa, Shiho,Katsuki, Tsutomu
, p. 2063 - 2066 (2007/10/02)
The nucleophilic addition of organometallics to α-keto amides having (2R,5R)-trans-2,5-bis(methoxymethoxymethyl)pyrrolidine as a chiral auxiliary was studied and it was found that the sense and degree of diastereoselection strongly depended on organometallics and the reaction conditions used and that the diastereomeric hydroxy amides was obtained with high stereoselectivity by the choice of appropriate reaction conditions.
