• Title/Summary/Keyword: Grignard reagents

Search Result 15, Processing Time 0.022 seconds

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
    • /
    • v.28 no.2
    • /
    • pp.281-284
    • /
    • 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
    • /
    • v.20 no.4
    • /
    • pp.441-444
    • /
    • 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.

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

  • Jung, Maeng-Joon;Lee, Chul-Jae;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.7 no.1
    • /
    • pp.107-113
    • /
    • 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.

  • PDF

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

  • Kim, Jung-Gyun;Yu, Dong-Sik;Moon, Sung-Hwan;Park, Jin-Il;Park, Won-Woo
    • Journal of the Korean Chemical Society
    • /
    • v.37 no.9
    • /
    • pp.826-831
    • /
    • 1993
  • 3-Cyanopyridine, when treated with organolithium or Grignard reagents, gives addition to the 6-position and provides a series of 2-substituted 5-cyanopyridines (6-substituted 3-cyanopyridines). Alternatively, 2-and 4-cyanopyridine react with $CH_3Li$ or $CH_3Mgl$ and provide 2-acetylpyridine and 4-acetylpyridine, respectively.

  • PDF

Nickel-Catalyzed Coupling of Arenesulfonates with Primary Alkylmagnesium Halides

  • Cho, Chul-Hee;Sun, Myung-Chul;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
    • /
    • v.26 no.9
    • /
    • pp.1410-1414
    • /
    • 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.