【作者】 刘颖杰；

【导师】 刘群； 王芒；

【作者基本信息】 东北师范大学 ， 有机化学， 2013， 博士

【摘要】 α-羰基二硫缩烯酮是一类具有多个反应位点的多官能团有机合成中间体，可广泛用于构筑各种碳环和杂环。经过一个多世纪尤其是近三十年的发展，α-羰基二硫缩烯酮化学已经成为有机化学合成领域的重要研究课题。由于α-羰基二硫缩烯酮-位双烷硫基的推电子作用和-羰基的拉电子作用，碳碳双键被高度极化， α-碳的电子云密度大大的增加，因而具有很高的亲核性，易与亲电体反应。因此， α-官能团化反应是二硫缩烯酮的重要反应之一。近年来，我们课题组先后实现了基于二硫缩烯酮-位的脱羧卤代和脱乙酰基卤代反应、与Baylis-Hillman加成物的反应、酰化反应、与醇的C–C偶联及多组分反应等，成功地将这些新反应应用到环己酮、不对称联苯、香豆素、吡啶衍生物、中氮茚、N-氧化吲哚等碳环和杂环的合成中。碳碳偶联反应是有机合成化学研究领域中重要的研究内容。探索基于二硫缩烯酮-位的新型碳碳偶联反应一直是我们课题组的主要研究内容。本论文对此进行了探索，论文内容主要包括：1．发展了一种在CuBr₂和BF₃Et₂O联合催下二硫缩烯酮和对苯醌的[3+2]环加成新反应，简捷、高效地合成了官能团化苯并呋喃衍生物。该方法反应条件温和、原料易得、催化剂廉价、产率高，产物具有丰富的官能团，经进一步修饰可转化为2-氨基苯并呋喃和苯并呋喃并嘧啶等化合物。2．发展了一种对苯醌单缩酮与二硫缩烯酮的区域选择性烯丙基取代新反应（SN2）。在SnCl4（1mol%）催化下，α-EWG二硫缩烯酮与对苯醌单经[3+2]环加成反应（EWG：拉电子基），高产率制备了多官能团化的苯并呋喃衍生物。该方法具有合成路线简洁、催化剂廉且用量少，反应具有高度的区域选择性等优点。反应所具有的区域选择性可认为系在SnCl4作用下，两反应物分子中的羰基通过分别与SnCl4的络合作用使反应中心接近，最终以一种假分子内的反应过程有关。3.发展了一种SnCl₄催化下，醌的单缩酮与插烯型硫酯[3+2]环加成反应，成功合成了具有潜在生物活性的天然产物Coumestans类似物。该方法条件温和、简捷、高效、区域选择性好。更多还原

【Abstract】 α-Oxo ketene dithioacetals are versatile intermediates in organic synthesis, and have avarity of chemical properties owing to their structural diversity.-Oxo ketene dithioacetalshave been widely applied to the construction of different kinds of poly stubstituted carbo-andheterocylic compounds. During a hundred years of development, exspecially in the past thirtyyears, the chemistry of α-oxo ketene dithioacetals has become an important research topic inorganic chemistry.In the structure of α-oxo ketene dithioacetals, the carbon-carbon double bond is highlypolarized due to the push-pull interreaction of the electron-withdrawing carbonyl group andelectron-donaying dialkylthio groups. Thus, the-carbon atom of a-oxo ketene dithioacetalis potentially a nucleophilic center, can react with a wide variety of electrophiles. As animportant property of α-functionalization f α-oxo ketene dithioacetals, in recent years wehave realized halodecarboxylation, halodeacetylation, C–C coupling with Baylis-Hillmanaducts, acetylation, C–C coupling coupling with alcohols, multi-component reactions, etc. Onthe other hand, great advances in the construction of a diverse array of polysubstituted carbo-and heterocyclic compounds, such as cyclohexanones, unsymmetrical biaryls, coumarins,pyridines, indolizines, indole N-oxides, were also realized.The C–C bond forming reaction is an important research topic in organic chemistry. Theexploration of new carbon-carbon forming reaction on α-C of α-oxo ketene dithioacetals hasbeen the chief goal of our research. This thesis will show some new exploratory work in thisfield, and mainly includes three aspects:1. We have developed a new CuBr2and BF3·Et2O cocatalyzed [3+2] cycloaddition ofα-EWG ketene dithioacetals with p-quinones, which provides a simple and general methodfor the synthesis of polyfunctionalized benzofurans. This protocol is associated with mildreaction conditions, readily available starting materials, cheap catalysts and good yields. Thiscatalytic cyclization strategy provides a facile access to a wide variety of benzofuranscontaining rich functionality. These functional groups can provide opportunities for furtherelaboration of these benzofurans to2-aminobenzofurans and benzofuro [2,3-d]pyrimidines.2. A new allylic substitution of quinone monoacetals and ketene dithioacetals has beendeveloped (SN2). Accordingly, a range of substituted benzofurans was synthesized in high toexcellent yields from quinone monoacetals and ketene dithioacetals via a formal [3+2]cycloaddition under tin tetrachloride (1%) catalyzed. The advantages of the reaction,including its simplicity, rapidity, low catalyst loading of inexpensive tin tetrachloride, and inparticular, the regiospecificity. The reason of high regioselectivity and efficiency of thereactions is the coordination of tin tetrachloride to the two participants can put reaction centercloser, and which is called a pseudo-intramolecular process.3. We have developed a new method for the synthesis of bioactive coumestans fromquinone monoacetals and vi-nylogous thioesters via a formal [3+2] cycloaddition under tin tetrachloride catalyzed. The advantages of the reaction including mild conditions, simplicityand regiospecificity.更多还原