ALKALOID SYNTHESIS BY MILD NITROGEN RADICAL METHODS

中性和质子化氮自由基(氨基)的反应 和胺阳离子自由基)分别在温和和 N-羟基吡啶-2-硫酮氨基甲酸酯的控制反应 将会被研究。同时生产单烷基和双烷基的方法 将开发取代的氮自由基。含氮自由基 含有远程双键环化得到5-和6- 以及溶剂和添加剂对反应的影响。 将研究这些反应的产率和立体选择性。 捕获生成的碳自由基中间体的方法 环化反应将得到发展；这些方法将是 对其他基于自由基的合成方法很有用。为了证明 利用这些方法，生物活性生物碱将被 通过含有氮基的路线合成的 通过环化来构建骨架。辅助研究将包括 胺基在远程功能化中的应用 含有酸敏性基团的底物中的碳原子 含氮自由基生成新方法的研究 亚胺的碳基加成。以氮为中心的 自由基环化将提供方便和快速进入 简单和复杂的生物碱家族，因此将在 多种生物活性和药用活性化合物的合成 重要的化合物。

The reactions of neutral and protonated nitrogen radicals (aminyl and aminium cation radicals, respectively) generated in mild and controlled reactions from N-hydroxypyridine-2-thione carbamates will be studied. Methods for producing both mono- and dialkyl substituted nitrogen radicals will be developed. Nitrogen radicals containing remote double bond cyclize to give five- and six- membered rings, and the influence of solvent and additives on the yields and stereoselectivities of these reactions will be studied. Methods for trapping the carbon radical intermediates formed in the cyclization reactions will be developed; these methods will be useful for other radical based synthetic methods. To demonstrate the utility of the methods, biologically active alkaloids will be synthesized by routes that incorporate the nitrogen radical cyclizations to build the skeletons. Ancillary studies will include the application of aminium radicals for remote functionalization of carbon atoms in substrates containing acid sensitive groups and investigations of new methods for generating nitrogen radicals by additions of carbon radicals to imines. The nitrogen centered radical cyclization will provide convenient and rapid enter to simple and complex alkaloid families and thus will be useful in the synthesis of a variety of biologically active and medicinally important compounds.