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Studies on the Development of New Generation Method of Nitrogene Centered Radicals and their Application to Intermolecular Cycloaddition Reaction

新型氮中心自由基生成方法的发展及其在分子间环加成反应中的应用研究

基本信息

批准号：
14572015
负责人：
KITAGAWA Osamu
金额：
$ 2.18万
依托单位：
Tokyo University of Pharmacy and Life Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

The present research is development of efficient generation method of various aza-homoallyl radical (2-alkenylated amidyl radicals) species using iodoaziridine derivatives and their application to intermolecular radical [3+2] cycloaddition reaction. The results in 2004 are as follows.1.Synthesis of optically active octahydroindole derivatives through asymmetric radical [3+2] cycloadditionIn last year, I reported asymmetric radical [3+2] cycloaddition using optically active bicyclic iodoaziridine. The product of the present reaction should be useful synthetic intermediate of various natural octahydroindole alkaloids. However, radical reaction is not generally useful for natural product synthesis, because remarkable decrease in the chemical yield is often observed by the scale up of the reaction. On the other hand, I found that the present reaction can scale up to 5 mmol without the decrease in the chemical yield and the stereoselectivity2.Radical cascade reaction of iodomethylcyclopropane derivative with dienes and enynesIn relation to the present reaction using iodoalkylated three-membered ring compound, I have reported iodine atom transfer radical [3+2] cycloaddition reaction using iodomethylcyclopropane having two electron-with drawing group on the ring. That is, in the present of triethylborane, the iodomethylcyclopropane efficiently generates allylated active methine radical which gives cyclopentane derivatives with good yields and stereoselectivities through the iodine atom transfer cycloaddition with various alkenes. In this year, I invesigated radical cascade reaction with dines and enynes. I found that the reaction of iodomethylcyclopropane with 1,4-dienes and 1,4-enynes gives bicycle [3.3.0] octane derivatives in good yields through [3+2] cycloaddition and subsequent 5-exo-cyclization.

本论文的主要工作是研究碘氮丙啶衍生物在分子间自由基[3+2]环加成反应中生成氮杂高烯丙基自由基（2-烯基化酰胺基自由基）的方法。2004年的研究结果如下：1.通过不对称自由基[3+2]环加成反应合成光学活性八氢吲哚衍生物去年，我报道了利用光学活性双环碘氮丙啶进行的不对称自由基[3+2]环加成反应。本反应的产物可作为多种天然八氢吲哚生物碱的合成中间体。然而，自由基反应通常不适用于天然产物的合成，因为通过反应的放大常常观察到化学产率的显著降低。2.碘甲基环丙烷衍生物与二烯和烯炔的自由基级联反应相对于使用碘烷基化三元环化合物的本反应，本文报道了碘原子转移自由基[3+2]环加成反应。即在三乙基硼烷存在下，碘甲基环丙烷有效地生成烯丙基化的活性次甲基自由基，通过碘原子转移环加成反应与各种烯烃进行环戊烷衍生物的合成，具有良好的产率和立体选择性。在这一年里，我研究了二烯炔类化合物的自由基级联反应。我发现碘甲基环丙烷与1，4-二烯和1，4-烯炔的反应通过[3+2]环加成和随后的5-外环化以良好的产率得到双环[3.3.0]辛烷衍生物。