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1998 Fiscal Year Final Research Report Summary

Hypervalent Interactionsin the Reactions Onium Salts of Main Group Elements

Research Project

Project/Area Number 09640634
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Organic chemistry
Research InstitutionOsaka University

Principal Investigator

OKUYAMA Tadashi  Osaka University Graduate School of Engineering Science, Associate Professor, 大学院・基礎工学研究科, 助教授 (40029484)

Project Period (FY) 1997 – 1998
KeywordsOnium Salt / Main Group Element / Iodonium Salt / Hypervalent Interaction / VinylicS_N2 Reaction / Benzenium Ion / Iodane / Sulfonium Salt
Research Abstract

Reactions of 1-decenyl (phenyl) iodonium salt with halide ions gave substitution products of complete inversion as well as n-elimination products. Analyses of UV spectroscopic and kinetic dependences on the halide concentrations show that the reactions occur via a hypervalent intermediate, lambda^3-haloiodane, formed in a rapid pre-equilibrium. By contrast, 2-halo-1-decenyl-iodonium salts gave substitution products of complete retention of configuration. This reaction is concluded to proceed via a ligand-couplingmechanism within an intermediatehaloiodane.
Solvolysis of styryl (phenyl) iodonium salt gave substitution products of both retention and inversion. Deuterium labeling experiments show that complete scrambling of the isotope between alpha and beta positions of the retention product but not of the inversion product. These results imply that the retention product is formed through a vinylenebenzenium ion while the inversion occurs by the in-plane S_N2 mechanims.
ALPHAbeta, beta-dialkylvinyliodonium salt gave a variety of products of extensive rearrangement of the beta-alkyI groups on solvolysis as well as reactions with halide ions. The alkyl group trans to the leaving iodonio group rearranges more readily than the cis group, but the cis group does rearrange significantly. Formation of the unrearranged substitution products is not stereospecific. These results are compatible with a reaction occurring mainly via beta-alkyl participation accompanied by a primary vinylic cation as an intermediate.
Rates for the reactions of 1-adamantylsulfonium salt with halide ions increase with halide concentration following a saturation curve. This strongly suggests intermediate formation of a hypervalent halosulfurane during this reaction.

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] 奥山 格: "Ligand coupling mechanism of nucleophilic vinylic substitution of iodonium salts with hypervalent 10-I-3 and 12-I-4 intermediates :" Chemistry Letters. 955-956 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 奥山 格: "Vinylic S_N2 reaction of 1-decenyliodonium salt with halideions" Bull.Chem.Soc.Jpn.71. 243-257 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 奥山 格: "In-plane vinylic S_N2 substitution and intramolecular β-elimination of β-alkylvinyl(phenyl)iodanes" J.Am.Chem.Soc.120. 2275-2282 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 奥山 格: "Reactions of phenylstyryliodonium salt with halideions" Bull.Chem.Soc.Jpn.71. 1915-1921 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 奥山 格: "Solvolysis of β,β-dialkylvinyliodoniu msalt : Primary vinyl cation intermediate and alkyl participation :" Chemistry Letters. 1177-1178 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 奥山 格: "Solvolysis of styryliodonium salt. Products,rates,and mechanisms" Bull.Chem.Soc.Jpn.72. 163-170 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Tadashi Okuyama: "Ligand coupling mechanism of nucleo-philic vinylic substitution of iodonium salts with hyperval-ent 10-I-3 and 12-I-4 intermediates" Chemistry Letters. 955-956 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tadashi Okuyama: "Vinylic S_N reaction of 1-decenyliodo-nium salt with halideions" Bull. Chem.Soc, Jpn.71. 243-257 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tadashi Okuyama: "In-plane vinylic S_N2 substitution and intramolecular beta-elimination of beta-alkylvinyl (phenyl) iodanes" J.Am.Chem, Soc.120. 2275-2282 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tadashi Okuyama: "Reactions of phenylstyliodonium salt with halideions" Bull.Chem.Soc.Jpn.71. 1915-1921 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tadashi Okuyama: "Solvolysis of beta, beta-dialkylvinyliodonium salt : Primary vinyl cation intermediate and alkylparticipation" Chemistry letters. 1177-1178 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tadashi Okuyama: "Solvolysis of styryliodoniumsalt.Products, rates, and mechanisms" Bull.Chem.Soc.Jpn.72. 163-170 (1999)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-12-08  

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