2008年12月
Efficient Formation of Ring Structures Utilizing Multisite Activation by Indium Catalysis
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
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- 巻
- 130
- 号
- 50
- 開始ページ
- 17161
- 終了ページ
- 17167
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/ja805657h
- 出版者・発行元
- AMER CHEMICAL SOC
Lewis acidic indium(III) salts, in particular In(NTf(2))(3), effect the conversion of alpha-(omega'-alkynyl)-beta-ketoesters; and omega-alkynyl-beta-ketoesters to the corresponding cyclic products in a manner known as the Coniaene reaction. This reaction can lead to the creation of five- to fifteen-membered-ring carbocycles and heterocycles in good to excellent yields. The synthetic features of the reaction are a relatively low catalyst loading, as low as 0.01 mol % in the best case, as well as no requirement of solvent for five-membered-ring formation and the requirement of only moderately dilute reaction conditions for medium-sized-ring formation. The high reactivity of indium salts is due to the double activation of the beta-ketoester substrate containing an acetylene function. The indium metal activates the beta-ketoester moiety by the formation of an indium enolate, and this indium metal electrophilically activates the alkyne moiety. Such a strong push-pull activation of the substrate by a single metal circumvents the disadvantage of entropic and enthalpic factors generally associated with the formation of medium- and large-sized rings. The reaction allows the ready formation of a fifteen-membered-ring carbocycle, from which di-muscone has been synthesized.
- リンク情報
- ID情報
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- DOI : 10.1021/ja805657h
- ISSN : 0002-7863
- J-Global ID : 200902284645215460
- Web of Science ID : WOS:000263320400059