| Co-Investigator(Kenkyū-buntansha) |
KITAGAKI Shinji Kanazawa University, Graduate School of Natural Science and Technology, Associate Professor, 自然科学研究科, 助教授 (20281818)
MIYAKOSHI Naoki Kanazawa University, Graduate School of Natural Science and Technology, Research, 自然科学研究科, 助手 (00345597)
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| Budget Amount *help |
¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 2006: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 2004: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Research Abstract |
This program has been directed toward development of efficient and novel reactions based on the inherent property of allenes, in particular, the allene possessing an electron-withdrawing group such as a phenylsulfonyl group. As a result, the following several reactions could be developed.
(1) Treatment of 1-phenylsulfonylallene with a proper (co-hydroxy) alkyl side chain at the C,-position with a base afforded the corresponding oxacycles through the endo-mode cyclization process. This novel ring-closing reaction could be applied for the construction of five-to nine-membered oxacycles. The aza-congeners as well as carbocycles were also found to be prepared according to the standard conditions, thus developed. The sulfoxide, phosphine oxide, phosphonate, and ester functionalities were used as an electron-withdrawing group instead a sulfonyl moiety. Furthermore, allenylaniline derivatives provided the corresponding 2,3-disubstituted indoles in an endo-mode ring-closing manner. The allenyla
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niline having a hydroxymethyl group was converted into the indole-2,3-quinodimethane derivative via the intramolecular SN2' reaction.
(2) The Pauson-Khand reaction of allenynes in the presence of Rh catalyst resulted in the efficient formation of bicyclo[4.3.0] as well as bicyclo[5.3.0] skeletons, the latter of which could not be prepared by the Pauson-Khand reaction of enynes. This new-type of Pauson-Khand reaction furnished the bicyclo[6.3.0] framswork as well. Alternatively, the carbodlimide functionality, which is isoelectronic to the allene group, could be successfully used in the Pauson-Khand reaction leading to the efficient construction of pyrrolo[2,3-b]indo1-2-ones.
(3) Reaction of ene-bisallenes, generated from the corresponding propargyl alcohols, underwent the 6π-electrocyclic reaction to afford the quinodimethanes, which were susceptible to the [4+2]cycloaddition reaction with dienophiles. This novel method for the generation of quinodimethane species could be applied for the production of the naphthoquinodimethanes from benzene-bridged bisallene. Interestingly enough, the proper choice of the conditions in the step of bis-allene formation produced the cyclobutene derivatives instead of the [4+2]cycloadducts even if the suitable dienophiles were in existence. Less
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