• 제목/요약/키워드: Grignard reagents

검색결과 15건 처리시간 0.026초

Nickel-Catalyzed Hydrogenolysis of Arenesulfonates Using Secondary Alkyl Grignard Reagents

  • Kim, Chul-Bae;Cho, Chul-Hee;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
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    • 제28권2호
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    • pp.281-284
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    • 2007
  • Neopentyl arenesulfonates react with secondary alkylmagnesium chlorides in the presence of dppfNiCl2 to produce the corresponding arenes via the reductive cleavage of carbon-sulfur bond. Highest yield is obtained by using three equivalents of Grignard reagent to a mixture of arenesulfonate and dppfNiCl2 in Et2O at room temperature. This reaction represents a novel method allowing the efficient hydrogenolysis of sulfur-containing groups in aromatic compounds.

Theoretical Study on the Regioselectivity of Tetrazolylimines with Alkyl Grignard Reagents

  • 유성은;공영대;김수경
    • Bulletin of the Korean Chemical Society
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    • 제20권4호
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    • pp.441-444
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    • 1999
  • The alkyl Grignard addition reaction on 1-benzyltetrazolylimine proceeds to give N-alkylated products (azophilic addition) and, in contrast, the same reaction on 2-benzyltetrazolylimine produced predominantly C-alkylated products (carbophilic addition). In this report we described theoretical explanations for this experimental finding on the basis of the frontier molecular orbitals and the electrostatic nature of the reactants and the reaction intermediates.

Aminophosphine류가 배위된 전이금속(Pd, Ni) 착물의 촉매반응; I. 탄소-탄소 짝지움 반응 (Catalytic Reactivity of Transition Metal (Pd, Ni) complexes with Aminophosphines; I. Carbon-Carbon coupling reactions)

  • 정맹준;이철재;김동엽
    • 한국산업융합학회 논문집
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    • 제7권1호
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    • pp.107-113
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    • 2004
  • Several transition metal complexes, [$M(L)X_2$](M=Pd(II), Ni(II); X=CI, Br) are prepared with aminophosphine ligands such as 1,2-bis{(diphenylphosphino)amino}ethane{$Ph_2PNHCH_2CH_2NHPPh_2$}($L_1$), 1,2-bis{(diphenylphosphino)amino}propane{$Ph_2PNHCH(CH_3)CH_2NHPPh_2$}($L_2$), trans-1,2-bis{(diphenylphosphino)amino}cyclohexane{$Ph_2PNHC_6H_{10}NHPPh_2$}($L_3$) and 1,2-bis{(diphenylphosphino)amino}benzene{$Ph_2PNHC_6H_4NHPPh_2$}($L_4$). The properties of these complexes are characterized by optical spectroscopic methods including UV/vis spectroscopy, CD, IR, $^1H$- and $^{31}P-NMR$ together with conductometer and elemental analysis. All complexes are stable under atmospheric environment. Catalytic reactivity for C-C coupling between [$M(L)X_2$] and Grignard reagents(RMgX; R=phenyl, propyl, buthyl) by thermolysis were investigated utilizing GC/mass, $^1H$- and $^{13}C-NMR$. When mol scale is 1:20 at [$Pd(L)Cl_2$] and Grignard reagents, the high catalytic activity for C-C coupling is apparent. The [$M(L)X_2$](X=Cl, Br) complexes which have strong bond at M-P exhibit high yields for C-C coupling reactions. When the central metal ion is Pd(II), the high catalytic activity for C-C coupling is apparent. The complex coordinated with Br shows higher catalytic activity for C-C coupling reactions compared to Cl.

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유기금속화합물에 의한 Cyanopyridines의 치환반응에 관한 연구 (Substitution Reactions of Cyanopyridines with Organometallics)

  • 김정균;유동식;문성환;박진일;박원우
    • 대한화학회지
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    • 제37권9호
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    • pp.826-831
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    • 1993
  • 3-Cyanopyridine을 organolithium 나 Grignard 시약과 반응시키면 6-위치에 첨가반응이 일어나 2-치환된 5-cyanopyridine류(6-치환된 3-cyanopyridine류)가 합성되었다. 반면, 2- 또는 4-cyanopyridine을 $CH_3Li$이나 $CH_3Mgl$와 반응시키면, 각각 2-acetylpyridine과 4-acetylpyridine이 합성되었다.

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Nickel-Catalyzed Coupling of Arenesulfonates with Primary Alkylmagnesium Halides

  • Cho, Chul-Hee;Sun, Myung-Chul;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
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    • 제26권9호
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    • pp.1410-1414
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    • 2005
  • Neopentyl arenesulfonates reacted with primary alkylmagnesium halides in the presence of $(PPh_3)_2NiCl_2$ to produce the corresponding alkylarenes. The efficiency of this coupling reaction considerably depends on the nature of catalyst and solvent. Highest yield was obtained by using three equivalents of Grignard reagent to a mixture of $(PPh_3)_2NiCl_2$ and arenesulfonate in refluxing $Et_2O$. This reaction represents a novel method allowing the efficient and creative substitution of sulfur-containing groups in aromatic compounds. It also shows that the alkyloxysulfonyl group might be a suitable alternative to halides and triflate in some circumstances.