1993 Fiscal Year Annual Research Report

ソルボリシス機構の統一的解釈

Research Project

Project/Area Number	02403010
Research Institution	KYUSHU UNIVERSITY
Principal Investigator	都野雄甫九州大学, 有機化学基礎研究センター, 教授 (10029845)
Keywords	ソルボリシス機構 / イオン対復帰 / イオン対中間体 / 0-18スクランブリング / 求核置換反応 / アリール関与機構 / 溶媒効果
Research Abstract	K_C基質であるt-ブチルベンジル、p-メチルチオ-m-ブロムベンジル、2-アダマンチルトシラートのソルボリシスにおいて全溶媒中で多量のイオン対復帰がみられ、その溶媒依存性は殆んど類似であった。酢酸ソーダ、アジドアニオン等の強求核剤や過塩素酸アニオンの添加にもイオン対復帰量は変化がなく、いわゆるK_C基質は、本質的に緊密イオン対中間体を含み、基質には殆んど無関係な、溶媒に固有の中間体イオン体復帰のエネルギー障壁を持つ事がわかった。従来のソルボリシスの溶媒解析にはイオン対復帰の考慮はK_Cソルボリシス基質に関する限りはあまり必要でない事がわかった。ベンジルトシラートのソルボリシスにおいては、p-メチル体、無置換体、m-クロロ体の順にカルボカチオンは不安定になり、S_N2性の高くなるにつれて、イオン体リターンは減少し、溶媒の求核性の増大およびイオン化能の低下とともにリターンは減少することがわかった。即ち、ボーダーライン基質の置換ベンジルソルボリシスではS_N2-S_N1競争を実証する結果を与えた。非ソルボリシス溶媒のアセトニトリル、アセトン中でも〓のスクランブリングが観測され、求核試剤のない条件下でもS_N1イオン化反応が存在する事実と、求核置換反応のS_N2と共存するS_<>1の解離速度を裏づける〓スクランブリング速度が実測された事実は、S_N2-S_N1機構の二元性を裏づけた。本研究で得られた事実は、ソルボリシス置換機構に対して、S_N2型置換遷移状態構造の"タイト"-"ルーズ"により律速画段階のエネルギー障壁位置の連続的変動の連続スペクトルとして解釈する1段階反応の協奏的S_N2と、イオン化、逐次的解離、求核種結合の逐次多段階反応を基本とするS_N1と考えるべきと結論される。

Research Products
(16 results)

All Other

All Publications (16 results)

[Publications] F.Hayakawa: "Silicon Effects.V.beta-Silicon Effect in the Solvolysis of 2-PhenylethylCompounds" Bull.Chem.Soc.Jpn.66. 153-157 (1993)
[Publications] S.D.Yoh: "Alkaline Hydrolysis of Substituted Benzyl Substituted Benzoates" J.Phys.Org.Chem.6. 23-28 (1993)
[Publications] M.Mishima: "Effect of the Twisted Nitro Group on Gas Phase Acidities of Phenol,Toluene,Aniline,and Benzoic Acid.Steric Inhibition of Intrinsic Resonance Effect" Chem.Lett.885-888 (1993)
[Publications] M.Mishima: "Substituent Effect on Electron Affinity of 2,6-Dimethylnitrobenzene" Chem.Lett.889-892 (1993)
[Publications] M.Mishima: "Electron Affinities of Benzaldehyde.Substituent Effects on Stabilities of Aromatic Radical Anions" Tetrahedron Lett.34. 4223-4226 (1993)
[Publications] T.Asano: "Mechanism of Thermal Z/E Isomerzation of Substituted N-Benzylideneanilines.Nature of the Activated Complex with a sp-Hybridized Nitrogen Atom" J.Org.Chem.58. 4418-4423 (1993)
[Publications] Y.Tsuji: "The Study of 18O-Scrambling theMenschutkin Reaction of p-Methylbenyl Tosylate with N,N-Dimethylanilines in Acetonitrile" Mem.Fac.Sci.,Kyushu Univ.,Ser.C. 19(1). 47-62 (1993)
[Publications] G.A.Ahmed: "Solvent Effects on the Solvolysis of Simple Alkyl Tosylates" Mem.Fac.Sci.,Kyushu Univ.,Ser.C22GD08:19(1). 63-80 (1993)
[Publications] K.Yatsugi: "Solvolysis of 1-Adamantylmetyl Tosylates" Mem.Fac.Sci.,Kyushu Univ.,Ser.C. 19(1). 81-96 (1993)
[Publications] S.Kobayashi: "Substituent Effect on Gas PhaseBasicity of 1-Phenylpropyne.Thermodynamic Stability and Resonance Demand of 1-Phenylpropenyl Cations" Tetrahedron Lett.34. 5903-5906 (1993)
[Publications] M.Fujio: "The Substituent Effect Studies of Aryl-assisted Solvolyses.I.The Acetolysis of 2,2-Bis(substituted phenyl)ethy Tosylates" Bull.Chem.Soc.Jpn.66. 3015-3020 (1993)
[Publications] M.Fujio: "The Substituent Effect Studies of Aryl-assisted Solvolyses.II.The Acetolysis of 2-Phenyl-2-(substituted phenyl)ethyl Tosylates" Bull.Chem.Soc.Jpn.66. 3021-3029 (1993)
[Publications] S.-D.Yoh: "Nucleophilic Substitution Reaction and Elimimnation Reaction of 2-Phenylethyl Arensulfonates" Bull.Korean Chem.Soc.14. 531-533 (1993)
[Publications] M.Fujio: "The Importance of Resonance Stabilization in the Benzylic Solvolysis.Substituent Effects on the Solvolysis of alpha,alpha-Diisopropylbenzyl Chlorides" Tetrahedron Lett.34. 8309-8312 (1993)
[Publications] K.Yatsugi: "Kinetic Effects of Thiourea Addition on Benzylic Solvolyses" Tetrahedron Lett.34. 135-138 (1994)
[Publications] N.Shimizu: "Silicon Effects.IV.b-Silicon Effect of Various Silyl Groups in Solvolysis for alpha-Alkylbenzyl and alpha-Silylbenzy Systems" Bull.Chem.Soc.Jpn.67. 500-504 (1994)

1993 Fiscal Year Annual Research Report

ソルボリシス機構の統一的解釈

Principal Investigator

都野 雄甫 九州大学, 有機化学基礎研究センター, 教授 (10029845)

Research Products

[Publications] F.Hayakawa: "Silicon Effects.V.beta-Silicon Effect in the Solvolysis of 2-PhenylethylCompounds" Bull.Chem.Soc.Jpn.66. 153-157 (1993)

[Publications] S.D.Yoh: "Alkaline Hydrolysis of Substituted Benzyl Substituted Benzoates" J.Phys.Org.Chem.6. 23-28 (1993)

[Publications] M.Mishima: "Effect of the Twisted Nitro Group on Gas Phase Acidities of Phenol,Toluene,Aniline,and Benzoic Acid.Steric Inhibition of Intrinsic Resonance Effect" Chem.Lett.885-888 (1993)

[Publications] M.Mishima: "Substituent Effect on Electron Affinity of 2,6-Dimethylnitrobenzene" Chem.Lett.889-892 (1993)

[Publications] M.Mishima: "Electron Affinities of Benzaldehyde.Substituent Effects on Stabilities of Aromatic Radical Anions" Tetrahedron Lett.34. 4223-4226 (1993)

[Publications] T.Asano: "Mechanism of Thermal Z/E Isomerzation of Substituted N-Benzylideneanilines.Nature of the Activated Complex with a sp-Hybridized Nitrogen Atom" J.Org.Chem.58. 4418-4423 (1993)

[Publications] Y.Tsuji: "The Study of 18O-Scrambling theMenschutkin Reaction of p-Methylbenyl Tosylate with N,N-Dimethylanilines in Acetonitrile" Mem.Fac.Sci.,Kyushu Univ.,Ser.C. 19(1). 47-62 (1993)

[Publications] G.A.Ahmed: "Solvent Effects on the Solvolysis of Simple Alkyl Tosylates" Mem.Fac.Sci.,Kyushu Univ.,Ser.C22GD08:19(1). 63-80 (1993)

[Publications] K.Yatsugi: "Solvolysis of 1-Adamantylmetyl Tosylates" Mem.Fac.Sci.,Kyushu Univ.,Ser.C. 19(1). 81-96 (1993)

[Publications] S.Kobayashi: "Substituent Effect on Gas PhaseBasicity of 1-Phenylpropyne.Thermodynamic Stability and Resonance Demand of 1-Phenylpropenyl Cations" Tetrahedron Lett.34. 5903-5906 (1993)

[Publications] M.Fujio: "The Substituent Effect Studies of Aryl-assisted Solvolyses.I.The Acetolysis of 2,2-Bis(substituted phenyl)ethy Tosylates" Bull.Chem.Soc.Jpn.66. 3015-3020 (1993)

[Publications] M.Fujio: "The Substituent Effect Studies of Aryl-assisted Solvolyses.II.The Acetolysis of 2-Phenyl-2-(substituted phenyl)ethyl Tosylates" Bull.Chem.Soc.Jpn.66. 3021-3029 (1993)

[Publications] S.-D.Yoh: "Nucleophilic Substitution Reaction and Elimimnation Reaction of 2-Phenylethyl Arensulfonates" Bull.Korean Chem.Soc.14. 531-533 (1993)

[Publications] M.Fujio: "The Importance of Resonance Stabilization in the Benzylic Solvolysis.Substituent Effects on the Solvolysis of alpha,alpha-Diisopropylbenzyl Chlorides" Tetrahedron Lett.34. 8309-8312 (1993)

[Publications] K.Yatsugi: "Kinetic Effects of Thiourea Addition on Benzylic Solvolyses" Tetrahedron Lett.34. 135-138 (1994)

[Publications] N.Shimizu: "Silicon Effects.IV.b-Silicon Effect of Various Silyl Groups in Solvolysis for alpha-Alkylbenzyl and alpha-Silylbenzy Systems" Bull.Chem.Soc.Jpn.67. 500-504 (1994)

都野雄甫九州大学, 有機化学基礎研究センター, 教授 (10029845)