| Project/Area Number |
15350061
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
RYU Ilhyong Osaka Prefecture University, Department of Chemistry, Professor, 総合科学部, 教授 (80210821)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUYAMA Takahide Osaka Prefecture University, Department of Chemistry, Assistant Professor, 総合科学部, 助手 (60332962)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥13,800,000 (Direct Cost: ¥13,800,000)
Fiscal Year 2004: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥10,400,000 (Direct Cost: ¥10,400,000)
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| Keywords | α-ketenyl radical / carbon monoxid / radical carbonylation / vinyl radical / alkyne / amine / 求核捕捉 / ラクタム / α-置換アクリル酸アミド / ラジカル連鎖機構 / 1,4-水素移動 / シクロペンタノン / メチレンラクトン / ラクトール / 環化反応 |
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| Research Abstract |
Synthetic chemistry of a-ketenyl radicals was investigated based on the reaction of vinyl radicals and CO. The radical carbonylation of 1,5-enynes was investigated using (TMS)_3SiH (TTMSS) and hexanethiol as radical mediator, which gave cylopentanones via 5-exo cyclization of α,β-unsaturated acyl radicals onto C-C double bond. Radical carbonylation of alkynylamines with tributyltin hydride gives a mixture of α-methylene lactams and α-stannylmethylene lactams. Nucleophilic addition of an internal amino group to the carbonyl group of α-ketenyl radicals is suggested as the key cyclization step. The subsequent unusual 1,4-H shift from the resulting 1-hydroxyallyl radical, followed by elimination of the β-tributyltin radical leads to the formation of α-methylene lactams. This radical/ionic combined concept can be extended to include intermolecular tripping reactions of α-ketenyl radicals by amines. The treatment of terminal alkynes with pressurized carbon monoxide, tributyltin hydride (30 mol%) and AIBN in the presence of excessive amines, led to give good yields of α-methylene amides. The generated α-ketenyl radicals then undergo nucleophilic trapping of a carbonyl group by amines leading to the production of 1-hydroxyallyl radicals, 1,4-H migration to give α-keto radicals, and β-elimination to give the tributyltin radical and α-alkyl acrylic amides. All these achievements represent new methods for alkyne carbonylations via α-ketenyl radicals.
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