• Title/Summary/Keyword: halides

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Correlation of the Rates of Solvolyses of Benzhydryl Halides Using an Extended Grunwald-Winstein Equation

  • Koh, Han-Joong;Kang, Suk-Jin;Kim, Cheol-Ju
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.378-382
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    • 2009
  • Rates of solvolyses of benzhydryl chloride ($Ph_2$CHCl, 1) and benzhydryl bromide ($Ph_2$CHBr, 2) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, 2,2,2-trifluoroethanol (TFE) and acetone are reported. Solvolyses were also carried out in TFE-ethanol mixtures. Application of the extended Grunwald-Winstein equation led to l value of 1.19 (1), 1.29 (2) and m value of 1.00 (1), 0.77 (2), correlation coefficient of 0.965 (1) and 0.970 (2). Sensitivities (l = 1.19 (1), 1.29 (2) and m = 1.00 (1), 0.77 (2)) were similar to those obtained for several previously studied solvolyses, in which an $S_N$2 pathway is proposed for the solvolyses of benzhydryl halides ($Ph_2$CHX, X = Cl or Br).

Rhodium-Catalyzed Highly Regioselective C-H Arylation of Imidazo[1,2-a]pyridines with Aryl Halides and Triflates

  • Liu, Yi;He, Lin;Yin, Guoqiang;Wu, Guojie;Cui, Yingde
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2340-2342
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    • 2013
  • A convenient Rh-catalyzed C-H arylation of imidazo[1,2-a]pyridines with a variety of aryl halides or triflates has been reported. This process afforded a range of biaryl compounds in excellent yields and showed high activity and broad scope.

Microwave Assisted, Solvent- and Ligand-Free Copper Catalyzed N-Arylation of Phenylurea with Aryl Halides

  • Gavade, Sandip;Shingare, Murlidhar;Mane, Dhananjay
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4167-4170
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    • 2011
  • An inexpensive and efficient catalyst system has been developed for the N-arylation of phenylurea including a variety of aryl halides. This simple protocol uses $Cu_2O$ as the catalyst, microwave assisted, solvent- and ligand-free, $K_3PO_4{\cdot}H_2O$ as the base.

Reactions with Hydrazidoyl Halides (V): Synthesis of Some Amidrazones, Hydrazides, Pyrazoles and Pyrazolo [3, 4-d] pyridazine Derivatives

  • Attaby, Fawzy A.;Zaki, Mayssoune Y.;Abdelhamid, Abdou O.;Ramadan, Nazmy A.
    • Archives of Pharmacal Research
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    • v.13 no.4
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    • pp.314-318
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    • 1990
  • 2-Bromo (2'-benzofury)gloxal-2-aryhydrazones I reacted with nucleophiles displacing the bromide. Treatment of I with active methylene compounds yield the pyrazole derivatives VIII-XI. Compounds XII-XIV reacted with hydrazine to give pyrazolo (3, 4-dipyridazine derivative XIV-XIV. The structures of the products were assigned and confirmed on the basis of their elemental analysis and spectral data.

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Kinetic Studies of Reactions of Transition Metal Carbonyl Anion with Allyl Halides

  • Park, Yong-Kwang;Han, In-Sup;Huh, Tae-Sung;Marcetta York Darensbourg
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.134-137
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    • 1989
  • The reaction of $CpMo(CO)_3-M^+(M^+,\;Li^+,\;Na^+,\;K^+,\;PPN^{+a})$ with allyl halide was performed and the details of its counterion effects and solvent effect was investigated under the pseudo-first order conditions. The kinetic data from this reaction were compared with those from the reaction of the same anion with benzyl halides in terms of their inverse counterion effects.

Thermal and Photoinduced Silylallylation Reactions of Organic Halides with 3-Stannyl-2-(silylmethyl)propene

  • 강경태;황성심;곽우영;윤웅찬
    • Bulletin of the Korean Chemical Society
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    • v.20 no.7
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    • pp.801-804
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    • 1999
  • Thermal and photoinduced silylallylation reactions of organic halides with 3-stannyl-2-(silylmethyl)propene are explored. Silylallylations occur in moderate to high yields, producing various functionalized allylsilane products in which halide carbon is bonded to the terminal alkenic carbon of allylsilane with the removal of tributyltin group. The reactions, which tolerate functional groups such as carbonyl, ester, nitrile, acetal, and ketal, hold synthetic potential for the construction of functionalized allylsilanes.

Cooperative Effects of Solvatochromic Parameters on the Ionizations of tert-Butyl Halides in MeOH-1,1,2,2-Tetrachloroethane Mixtures (MeOH-1,1,2,2-Tetrachloroethane 혼합용매에서 tert-Butyl Halides의 이온화에 미치는 분광용매화변수들의 협동효과)

  • Yeol Sakong;Shi Choon KIm;Jae Bum Choo
    • Journal of the Korean Chemical Society
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    • v.30 no.3
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    • pp.265-272
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    • 1986
  • Kinetic studies for the methanolysis of tert-butyl halides (t-BuCl, t-BuBr, t-BuI) were carried out in MeOH-1,1,2,2-tetrachloroethane mixtures. The solvatochromic comparison method was used with six indicators to analyze solvent effects on the ionizations of tert-butyl halides. It was shown that the cooperative effect of solvent polarity-polarizability was the most important factor influenced on the methanolysis rates of tert-butyl halides, but the electrophilic assistance for halide leaving group and the nucleophilic assistance for tert-butylium ion were considerably influential, too. And it was found that the electrophilic assistance caused by hydrogen bonding and the nucleophilic assistance for carbon center were stronger for more basic leaving group ($I^-) and more polarizable leaving group(t-BuCl

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