【作者】 谢永发；

【导师】 周宏伟；

【作者基本信息】 浙江大学 ， 有机化学， 2010， 硕士

【摘要】 由于硫原子比氧原子的原子半径大,硫负离子的亲核性要比氧负离子强,硫在有机合成中也容易形成硫鎓正离子,含有烯丙基烯基硫醚结构单元的化合物也容易发生[3,3]δ重排,所以硫参与是有机合成中构建杂环化合物的重要的手段。近年来也有很多的研究工作者通过硫参与的方法合成了很多的杂环化合物,本论文中,我们也是利用硫参与的方法合成了一系列的茚的衍生物和噻吩的衍生物。茚是许多天然产物和药物的重要结构单元,也可以作为合成相关化合物的重要合成前体。本论文的第二章中我们以烷硫基取代的烯烃作为原料,用三氟甲磺酸酐和过量碱(吡啶)存在下合成了一系列的茚的衍生物,反应过程中以环状的硫鎓正离子中间体的机理构成茚环,其机理我们已经从侧面进行了证明。这种合成茚的衍生物的新方法具有无金属催化、原料易得、官能团适用性好的优点。噻吩的衍生物在医药合成、农药、染料、功能材料上有广泛的应用。本论文的第三章中,我们研究了硫参与的五步串联反应:炔丙基的联烯重排、硫参与的Claisen重排、硫酮的烯醇化、Michael加成和1,5-H迁移来合成一系列的噻吩衍生物,我们研究了此反应的最佳反应条件,研究了这个反应的官能团的适用性,也用氘代的方法研究了这个反应的反应机理。我们所报道的这种合成噻吩的新反应只需要在常温的条件下,用有机碱DBU(1,5-二氮杂二坏[5.4.0]十一-5-烯),以较快的速率、较高的产率生成相应的产物,是一种合成噻吩衍生物的简便方法。更多还原

【Abstract】 The nucleophilicity of sulfur anion is stronger than oxygen anion due to its atomic radius and sulfur is also inclined to form sulfonium ion intermediate in organic synthesis. Sulfur participation is significant in organic synthesis to construct the heterocyclic compounds. Thio-Claisen rearrangement (TCR), classically a [3, 3] sigmatropic rearrangement in the allyl vinyl sulfides leading to a homoallyl thiocarbonyl unit, has received considerable attention in the past decades. In this dissertation, a series of indene derivatives and thiophene derivatives were synthesized via the sulfur participation strategy.The indenes moiety is present in a class of drug candidates possessing interesting biological activities, and also could be principal precursors in organic synthesis. In the second section of this dissertation, an intramoluclar addition of sulfur-participated Nazarov-type cyclization affording 3-thio-1H-indenes was reported. As a result of the ready availability of starting materials and the simple and convenient operation, this type of reaction presented here has potential utility in organic synthesis.In the third section of this dissertation, A sulfur-assisted five-cascade sequential reaction, wherein the in situ-generated allenyl allyl sulfides undergo thio-Claisen rearrangement, intramolecular Michael addition, and 1, 5-proton migration aromatization to obtain allyl thiophen-2-yl acetates, propionates, and ketones as thefinal products, was reported. Application of this efficient method for the synthesis of potentially pharmaceutical compounds also might be useful for the pharmacists.更多还原