| Project/Area Number |
08454228
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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 |
物質変換
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| Research Institution | University of Tsukuba |
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Principal Investigator |
HOSOMI Akira University of Tsnkuba, Chemistry, Professor, 化学系, 教授 (00004440)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Hajime University of Tsnkuba, Chemistry, Assistant, 化学系, 助手 (90282300)
MIURA Katsukiyo University of Tsnkuba, Chemistry, Lecturer, 化学系, 講師 (20251035)
HOJO Makoto University of Tsukuba, Chemistry, Lecturer, 化学系, 講師 (50229150)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,900,000 (Direct Cost: ¥7,900,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Si-Cu exchange reaction / Stereoselective synthesis / Carbonyl ylides / Reductive metalation / Radicai Reactions / Samarium-mediated reactions / [3+2] Cycloaddition / Silicon-directed cyclization / 有機マンガンアート化合物 / アルドール反応 / アリルマンガンアート反応剤 / プロバルギルマンガンアート反応剤 / マンガンエノラート / テトラブチルマンガナ-ト錯体 / 有機金属化合物 / ビニルラジカル / 有機合成 / 高選択的反応 / トリブチルスタンナン |
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| Research Abstract |
The following results are obtained in this research project.
1.Silicon-directed Cyclization of Vinylysilanes : Stereoselective Synthesis of Tetrahydrofuranes and Tetrahydropyranes
Silicon-directed stereoselective syn addition of hydroxy group to olefinic double bond occurs intramolecularly in an acid-catalyzed cyclization of vinylsilanes bearing hydroxy group. Thus 5-dimethylphenylsilyl-4-penten-1-ol is smoothly cyclized to 2- (dimethylphenylsilyl) methyltetrahydrofuran upon the treatment of a catalytic amount of p-toluenesulfonic acid (TsOH) or TiCl_4.
2.Unprecedented Samarium-Mediated Reactions : Generation of Non-Stabilized Carbonyl Ylids
Samarium reveals a strong reducing ability and by virtue of this character together with its oxophilicity, is widely applied to organic synthesis in the formation of carbon-carbon bonds and transformation of a variety of functionalities with high selectivities. In the course of our study on the generation and reactions of reactive species, we report he
… More
rein the generation of novel active species, non-stabilized carbonyl ylids from iodomethyl silyl ethers mediated by samarium, otherwise inaccessible, and their [3+2] cycloadditions to a variety of unsaturated compounds such as aldehydes, alkenes, allenes, and alkynes.
3.Manganese AteSpecies : Generation and Reactions with Electrophiles
Tetrabutylmanganese ate complex 'Bu_4MnLi_2' reacts with allylic and prop-2-ynylic bromides to generate the corresponding allyl-and prop-2-ynyl-manganese species which further react with electrophiles such as aldehydes, ketones, epoxide, and chlorosilanes to afford the corresponding allylated and prop-2-ynylated and/or allenylated products in high yields.
4.Allylstannylation of Alkynes and Alkenes via a Radical Process : Stereoselective Synthesis of Di-and Tri-Substituted Vinylstannanes
In the presence of AIBN,allylstannanes bearing an electron-withdrawing group at the beta-position easily reacted with terminal and electron-deficient internal alkynes to give beta-allyl-substituted vinylstannanes in moderate to good yields. The allylstannylation proceeds with anti addition exclusively. Allylstannanes bearing an electron-withdrawing group at the beta-position easily reacted with various electron-deficient alkenes to introduce both the allyl and stannyl groups. Less
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