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以芳基硫酚为原料的C-S键生成反应方法研究

New Methods of C-S Bond Formation from Aryl Thiols

【作者】 廖云峰

【导师】 邓国军;

【作者基本信息】 湘潭大学 , 有机化学, 2013, 博士

【摘要】 硫元素是自然界中重要的元素之一,含硫有机化合物在医药、农药、材料等领域有着广泛的应用。C-S键的构筑是有机化学重要研究内容和持续关注的热点之一,发展原料易得、条件温和的C-S键生成反应是有机合成化学的研究重点。近年来,许多新型、高效、高选择性的C-S键构筑方法被报道出来。本论文以苯硫酚及其衍生物为研究对象,开展了芳基硫酚和环己酮、芳香酮、苯乙炔及其衍生物的C-S键生成反应研究。主要研究内容如下:1、研究了碘催化下芳基硫酚和环己酮及其衍生物的C-S键生成反应,合成了一系列的2-芳基硫醚基苯酚,产率良好。在该反应中,环己酮经过C-S键生成、脱氢、芳构化等过程作为芳基酚来源。该反应体系以碘为催化剂、以氧气作绿色的氢接受剂,反应中没有使用任何金属化合物,副产物只有水,该方法为合成2-芳基硫醚基苯酚提供了一种高效、环境友好的新途径。另外,还发展了芳基磺酰肼和环己酮合成2-芳基硫醚基苯酚的C-S键生成反应。该反应中,使用了化学当量的碘作为添加物,在类似的条件下得到2-芳基硫醚基苯酚,产率较好。2、发展了邻氨基苯硫酚类化合物和环己酮及其衍生物生成吩噻嗪的C-S键生成反应,环己酮经过缩合、成环、氧化脱氢、芳构化等步骤作为芳基的来源。催化剂量的苄基砜基苯和碘化钾同时使用可以显著提高反应产率,不需要使用过渡金属催化剂,氧气作为绿色的氧化剂。该方法为合成吩噻嗪及其衍生物提供了一种简单、绿色的新途径。3、以2-氨基苯硫酚和苯乙酮及其衍生物为原料通过C-S键生成反应合成了一系列的2-芳基苯并噻唑。该反应以氧气作为氧化剂,反应过程中不需要使用任何金属催化剂,DMSO在反应中起到了至关重要的作用。功能基团例如:甲基、甲氧基、氟、氯、溴和硝基等在反应中都能够稳定存在。该方法以廉价、稳定的芳基酮为原料,可以为2-芳基苯并噻唑的合成提供一条新的途径。4、报道了一种由芳基硫醚和炔类化合物合成反马氏烯基硫醚的新方法,该方法不需要过渡金属催化剂。以廉价易得的无水磷酸钾作为碱,以NMP为溶剂,高选择性地得到Z式烯基硫醚。E式烯硫醚可以在无溶剂的条件下合成,反应的立体选择性较相应的Z式烯基硫醚低。

【Abstract】 Sulfur is one of the most important elements in nature. Sulfur-containing organiccompounds play important roles in the pharmaceuticals, agricultural chemicals andmaterials science. The C-S bond formation is one of the most exciting research topicsin organic chemistry and has been attracted sustained attention. The construction ofC-S bond under mild reaction conditions from cheap and readily avilable materials isbecoming focus of study. Many efficient methods for the C-S bond formation havebeen developed in the past decades. We investigated a variety of C-S bond formationreactions involving arylthiols, which can be reacted with aryl ketones,cyclohexanones and acetylenes. Detailed research was described as follows:1. A series of2-arylsulfanylphenols were synthesized by iodine-catalyzedtransformation based on C-S bond formation from benzenethiols and cyclohexanones.The C-S bond formation, dehydrogenation and tautomerization were realized inone-pot without any metal-catalyst and cyclohexanones were used as phenol source.Catalytic amount of iodine was used as catalyst and molecule oxygen was used ashydrogen acceptor in this transformation. This method can afford an efficient andenvironmentally benign approach for2-arylsulfanylphenols from readily availablematerials. In addition,2-arylsulfanylphenols were also could be prepared frombenzenesulfonohydrazides and cyclohexanones using stoichiometric amounts ofiodine as additive under similar conditions in good yields.2. The construction of C-S bond reaction for phenothiazine formation wasreported from cyclohexanones and2-aminobenzenethiols. Cyclohexanones were usedas aryl source by condensation, tautomerization, cyclization and dehydrogenationtransformation. The combination use of catalytic amount of benzyl phenyl sulfone andKI significantly improved the reaction yields using molecular oxygen as hydrogenacceptor in the absence of transition-metals. It will provide a novel, convenient andenvironmentally benign method for the synthesis of phenothiazines.3. A facile synthesis of2-aryl benzothiazoles via C-S bond formation reactionusing molecular oxygen as oxidant under metal-free conditions have beensuccessfully developed. DMSO played an important role in this transformation.Functional groups such as methyl, methoxy, fluoro, chloro, bromo and nitro were allwell tolerated under the optimized reaction conditions. Since aryl ketones are cheap,readily available starting materials, this method afforded an efficient alternative route for the rapid synthesis of2-aryl benzothiazoles.4. An efficient anti-Markovnikov hydrothiolation from acetylenes and arylthiolsunder transition-metal-free conditions is described. The choice of base and solventsignificantly affected the reaction selectivity. When potassium phosphate was used asbase in NMP, the Z-vinyl sulfides were formed in good yields and high regio-andstereoselectivity. Whereas E-vinyl sulfides were the major products when the reactionwas carried out in neat without any additive in good yields.

  • 【网络出版投稿人】 湘潭大学
  • 【网络出版年期】2014年 05期
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