• Title/Summary/Keyword: trimethylsilyl

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Synthesis of 1,1-Dimethyl-2,5-bis(trimethylsilyl)-3,4-diphenyl-1-silacyclopenta-2,4-diene (1,1-Dimethyl-2,5-bis(trimethylsilyl)-3,4-diphenyl-1-silacyclopenta-2,4-diene의 합성)

  • Young Kun Kong;Wan-Chul Joo
    • Journal of the Korean Chemical Society
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    • v.30 no.6
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    • pp.521-525
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    • 1986
  • From the reaction of phenyltrimethylsilylacetylene with lithium, 1,4-bis(trimethylsilyl)-2,3-diphenyl-1,4-butadene dianion was formed. The reaction of dianion with dichlorodimethylsilane affords 1,1-dimethyl-2,5-bis(trimethylsilyl)-3,4-diphenyl-1-silacyclopenta-2,4-diene. In addition 1,4-bis(trimethylsilyl)-2,3-diphenyl-1,3-butadiene was isolated. It seems to be hydrolized product in alkali medium.

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Efficient Preparation of 3-Fluoropyrrole Derivatives

  • Kim, Bo-Mi;San, Quan-Ze;Bhatt, Lok Ranjan;Kim, Sung-Kwon;Chai, Kyu-Yun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.1
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    • pp.31-34
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    • 2010
  • Noble N-substituted-3-fluoropyrroles derivatives were prepared from new precursor via ring formation. The addition reaction of ethyl iododifluoroacetate to vinyl trimethylsilane under the Cu(0) catalyst resulted in the formation of ethyl-2,2-difluoro-4-iodo-4-(trimethylsilyl)butanolate, which reacted with diisobutylaluminium hydride at $-30^{\circ}C$ to yield 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal. Finally, a series of N-substituted-3-fluoropyrrole derivatives were synthesized by the reaction of 2,2-diflouro-4-iodo-4-(trimethylsilyl)butanal with $NH_4OH$ or primary amines followed by reaction with KF solution.

Synthesis and Reactivity of Dinuclear Ni(II) Azido Complexes Containing Bithienylene or Terthienylene Bridging Ligands

  • Kim, Yong-Joo;Lee, Hyuck-Hee;Zheng, Zhen Nu;Lee, Soon-W.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3239-3244
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    • 2011
  • Dinuclear Ni(II)-thiophene halides, which contain linear bridging thienylenes, trans,trans-[$(PR_3)_2$(X)Ni-Y-Ni(X)$(PR_3)_2$] {X = Cl, Br; $H_2Y$ = 5,5'-dichloro-2,2'-bithiophene ($H_2bth$); $H_2tth$ = 5,5"-dichloro-2,2':5',2''-terthiophene ($H_2tth$)} were prepared by the oxidative addition of dihalobithiophene ($H_2bth$) or dihaloterthiophene ($H_2tth$) to [$Ni(COD)_2$] in the presence of tertiary phosphines. Subsequent reactions of $NaN_3$ with the dinuclear Ni(II)-thiophene chlorides gave the corresponding Ni(II)-azido complexes, trans,trans-[$(PR_3)_2(N_3)$Ni-Y-Ni$(N_3)(PR_3)_2$], whose reactivity toward trimethylsilyl pseudohalides such as trimethylsilyl isothiocyanates and cyanides was investigated. In addition, the reaction of trans-[$BrNi(PEt_3)_2-C_4H_2S-C_4H_2S$-CHO], a thienyl Ni(II) complex containing a terminal aldehyde group, with phosphonium ylide was examined.

Synthesis of 2-n-Butyl-3-fluoropyrrole Derivatives

  • Kim, Bo-Mi;San, Quan-Ze;Bhatt, Lok Ranjan;Jung, Dong-Woon;Lee, Young-Hang;Chai, Kyu-Yun
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1293-1296
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    • 2009
  • A new series of N-substituted 2-n-butyl-3-fluoropyrroles were prepared by a simple one-pot reaction designed of retrosynthesis. $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl)propyl n-butyl ketone, a component precursor molecule to 2-n-butyl-3-fluoropyrroles, was prepared with Cu(0) catalyst. It reacted with various primary amines to yield N-substituted 2-n-butyl-3-fluoropyrroles. The products were synthesized via a one-pot reaction scheme between $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl) propyl n-butyl ketone and primary amines in excess ( $\geq$ 5 molar equivalence), which eliminate the need of KF required in obtaining n-butyl-1H-3-fluoropyrrole. The yield of products depended reversely on spatial bulkness around N-binding carbon.

GC-MS analysis of Salicornia herbacea L. extracts with trimethylsilyl derivatization (Trimethylsilyl 유도체화 방법을 적용한 함초 추출물의 GC-MS 분석)

  • Kyoung-In Lee;Geun-Jik Lee;Young-Seung Yoon
    • Journal of Marine Bioscience and Biotechnology
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    • v.15 no.2
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    • pp.96-102
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    • 2023
  • Salicornia herbacea, a noted halophyte, has been widely researched for its diverse physiological activities. The continuous exploration of its compounds is essential. This study employed gas chromatography (GC) coupled with mass spectrometry (MS) for qualitative analysis. This involved pretreatment including trimethylsilyl (TMS) derivatization of the S. herbacea extract, facilitating its GC analysis. Five compounds, including various fatty acids and β-sitosterol, were identified by direct analysis of the methanol extract of S. herbacea without pretreatment by GC-MS. Conversely, the analysis of the TMS-derivatized extract revealed 28 distinct peaks. Quantitative analysis further indicated that the predominant compounds in the S. herbacea extract were sugars and sugar derivatives, notably glucose, fructose, and glucitol. The collective concentration of these sugars and its derivatives amounted to 116.45 mg/g, representing 11.6% of the dry weight of the raw S. herbacea. Following sugars and their derivatives, fatty acids constituted the next most abundant group of compounds. However, the presence of amino acids and organic acids was relatively low.

Studies of Silyl-Transfer Photochemical Reactions of N-[(Trimethylsilyl)alkyl]saccharins

  • Cho, Dae-Won;Oh, Sun-Wha;Kim, Dong-Uk;Park, Hea-Jung;Xue, Jin-Ying;Yoon, Ung-Chan;Mariano, Patrick S.
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2453-2458
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    • 2010
  • Photochemical studies of N-[(trimethylsilyl)alkyl]saccharins were carried out to investigate their photochemical behavior. Depending on the nature of the substrate and the solvent system employed, reactions of these substances can take place by either SET-promoted silyl migration from carbon to either the amide carbonyl or sulfonyl oxygen or by a N-S homolysis route. The results of the current studies show that an azomethine ylide, arising from a SET-promoted silyl migration pathway, is generated in photoreactions of N-[(trimethylsilyl)methyl]saccharin and this intermediate reacts to give various photoproducts depending on the conditions employed. In addition, irradiation of N-[(trimethylsily)ethyl]saccharin produces an excited state that reacts through two pathways, the relative importance is governed by solvent polarity and protic nature. Finally, photoirradiation of N-[(trimethylsilyl)propyl]saccharin in a highly polar solvent system comprised of 35% aqueous MeOH gives rise to formation of a tricyclic pyrrolizidine and saccharin that generated via competitive SET-promoted silyl transfer and $\gamma$-hydrogen abstraction pathways.

An Efficient Method for Selective Deprotection of Trimethylsilyl Ethers and Tetrahydropyranyl Ethers under Solvent-free Conditions

  • Hajipour, A.R.;Bagheri, Hamid R.;Ruoho, Arnold E.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1689-1691
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    • 2005
  • 1-Butyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (BAABOD) 3 is a useful reagent for the selective cleavage of trimethylsilyl ethers and tetrahydropyranyl ethers to their corresponding aldehydes and ketones in the presence of $AlCl_3$ under solvent-free conditions. This method is very simple and efficient and the reaction has been carried out under solvent-free conditions in the presence of a catalytically amount of aluminum chloride.

Comparative Studies on Two Types Derivatives of Gibberellins for the Gibberellin Analysis by Gas Chromatography-Selected Ion Monitoring (GC-SIM에 의한 두종의 gibberellin유도체의 분석)

  • Park, Keun-Hyung
    • Applied Biological Chemistry
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    • v.28 no.2
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    • pp.82-87
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    • 1985
  • Aiming at the improvement of accuracy and sensitivity of gibberellin analysis by gas chromatography-selected ion monitoring (GC-SIM), the mass spectra of two types of 29 gibberellin derivatives, methyl ester-trimethylsilyl ethers and trimethylsilyl ester-trimethylsilyl ethers, were obtained and their advantages and disadvantages in GC-SIM analysis are discussed.

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