| Project/Area Number |
08640686
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Organic chemistry
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| Research Institution | NARA UNIVERSITY OF EDUCATION |
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Principal Investigator |
YAMAZAKI Shoko NARA UNIVERSITY OF EDUCATION,ASSISTANT, 教育学部, 助教授 (50182481)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | Selenosilylethene / [2+1]Cycloaddition Reactions / Cyclopropanation / Pyrethroid insecticides / Aminocyclopropanecarboxylic acid / Aminocyclopropanephosphonic acid / Lewis Acid / Silicon 1,2-shift / セレノシリンエテン / [2+1]環化付加反応 / 〔2+1〕環化付加反応 / アミノミクロプロパンカルボン酸 / コロナミン酸 / 臭化亜鉛 / トリカルボニル置換オレフィン |
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| Research Abstract |
1. The reactions of 1-seleno-2-silylethenes 1 with highly electrophilic tricarbonyl-substitued olefins in the presence of Lewis acids have been investigated. The reaction of 1-phenylseleno-2-trimethylsilylethene (la) with tri(alkoxycarbonyl) olefins 2 or 1,1-di(alkoxycarbonyl)-2-acyl olefins 3 in the presence of ZnBr_2 at -30ﾟC gave cis-substituted cyclopropanes exclusively. The origin of the cis stereochemistry was ascribed to the synclinal addition path of the ZnBr_2-coordinated electrophilic olefin to 1. Application of the highly functionalized selenium- and silicon-substituted cyclopropane products to the preparation of a useful synthetic intermediate, for the pyrethroid class of insecticides was also demonstrated.
2. [2+11 Cycloaddition reaction between 1-phenylseleno-2-triethylsilylethene (1b) and di-t-butylmethylene malonate (4) in the presence of ZnX_2 (X = Br, I) was applied to a novel synthesis of aminocyclopropane derivatives. The high functionality of the cyclopropane product (5) was utilized for stereoselective conversion to (E)-2-substituted 1 -anilnocyclopropane-1-carboxylic acid derivatives such as (*)-coronamic acid and an alkyl derivative and a 2,3-methanoaspartic acid derivative. The selenosilylmethyl group in 5 functioned as a stereocontrolling group for mono-reduction and as a formyl or carboxyl group equivalent in the subsequent step.
3. Stereoselective SnCl_4-promoted [2+1] cycloaddition reactions of 1-seleno-2-silylethene 1 with 2-phosphonoacrylates 6 lead to highly functionalized cyclopropanephosphonate esters 7 in high yield. The cyclopropane products 7 are potentially versatile starting materials for biologically important compounds. Stereoselective synthesis of a novel functionalized alpha-aminophosphonic acid derivative, an analog of (Z)-2,3-methanohomoserine, from the cycloadduct 7b was achieved. Stereoselectivity in the [2+1] cycloaddition was explained by consideration of the structure of the 6-SnCl_4 complex.
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