【作者】 贺鹰；

【导师】 陆明；

【作者基本信息】 南京理工大学 ， 应用化学， 2014， 博士

【摘要】 氧化反应是一类极其重要的反应,它占据了有机合成的三分之一,应用于有机合成的许多领域。传统的氧化工艺大多数采用化学计量的氧化剂,这些氧化剂存在污染环境和成本较高等问题。双氧水是廉价、安全及环境友好的氧化剂,其副产物是水。因此,以双氧水为氧化剂的氧化反应被有机化学工作者长期关注。含硫化合物、羰基化合物和环氧化合物是有机合成的重要原料和中间体。虽然报道的氧化方法很多,但还存在催化剂活性低、反应时间长、对底物适用范围不广、催化剂难以回收等缺点。因此,研究和开发出以双氧水作为氧化剂,简单、反应温和、经济、环境友好、高效催化氧化体系的新方法无论在实践还是在理论方面都具有重要的意义。本论文主要研究了在水介质中以双氧水为氧化剂,实施对硫醚制备亚砜或砜,硫醇制备对称双硫化合物,仲醇制备酮,苄基卤制备醛、酮和烯烃环氧化等氧化反应,以期开发出对环境友好的新方法,具体的研究内容包括以下几个方面。在实施硫醚制备亚砜或砜氧化反应中,分别研究了Na2WO4/三辛基甲基磷酸二氢铵(PTC)催化氧化体系,在羟丙基环糊精(HP-β-CD)存在下,对氧化反应选择性的影响规律。研究表明,在Na2WO4/PTC/HP-β-CD存在下,温度控制在-5-0℃,氧化反应能够较好的控制在亚砜阶段；而仅在Na2WO4/PTC存在下,温度控制在50-60℃,氧化反应能够较好的制备砜,收率高于90%。整个反应过程条件温和,选择性好,后处理简单,无有机溶剂,实现了环境友好的硫醚制备亚砜或砜。以水做溶剂,TBAI(四丁基碘化铵)为催化剂,氧化硫醇制备对称双硫化合物的反应。研究发现TBAI/30%H2O2催化体系室温下可以高效的催化硫醇制备对称双硫化合物,反应收率在90%以上。与之前报道的氧化体系进行比较,该氧化反应体系具有廉价,选择性好,条件温和,反应快,操作简单,反应结束后,产物容易分离,明显优于先前报道的氧化反应体系。以1,3,5-三溴甲基-2,4,6-三甲基苯为原料与三乙胺反应生成三核季铵盐,然后该季铵盐与磷钨酸配位合成新型的三核催化剂TBAP,发现了这种催化剂具有良好的温控两相的性质,并将其用于催化氧化仲醇的反应。实验表明,TBAP/30%H2O2氧化反应体系,反应速度较快,只需要2-4h,就可以催化氧化仲醇制备酮。用5%H202可以氧化苄醇到相应的醛。反应结束后,产物与催化剂形成液-固两相,通过简单的过滤便可实现产物与催化剂的分离。催化剂可以方便的回收循环使用而催化活性基本保持不变。在苄基卤制备醛或酮的反应中,开发了一种TEMPO/30%H2O2催化氧化的新方法。考察了各种因素对反应的影响,研究了氧化反应机理。实验表明,溴化钠作为助催化剂可以加速反应,缩短反应时间,该氧化反应体系可以氧化不同取代基(吸电子基或供电子基团)的苄卤到醛或酮。在不加溴化钠作助催化剂的条件下,含溴的苄基底物的活性明显高于含氯的苄基底物。以自制三核铁配合物(TPTTTI)为催化剂,联二吡啶为有机碱,双氧水对烯烃的环氧化反应中,考察了催化剂量、溶剂、温度、不同氧化剂等因素对环氧化反应的影响。研究结果表明,TPTTTI对双键的环氧化具有良好的催化效果。联二吡啶能有效的抑制环氧化产物在催化剂固有的酸性条件下,开环生成过氧化杂质,同时缩短环氧化反应时间。更多还原

【Abstract】 Oxidation reaction is the most important synthetic transformation in organic chemistry, which occupy one third of the areas. Commonly, traditional oxidation reaction employs the stoichiometric oxidizing agents, which are expensive, hazardous or toxic. Meanwhile toxic solvent is usually used to dissolve oxidizing agent and a large amount of inorganic waste is produced after workup. Hence, in terms of economical and environment concern, catalytic oxidation process with inexpensive and environmental-friendly oxidant is extremely valuable. Hydrogen peroxide is an oxidant of ideal choice. It is cheap, readily available and gives water as the only byproduct. Among various oxidizing agents, hydrogen peroxide as benign oxidant has attracted organic chemists’attention for a long time. Organosulfur compounds, carbonyl compounds and epoxy compounds are important raw materials and intermediates in organic synthesis. Although many different catalytic oxidation systems are developed to overcome the limitations of conventional methods, most of them still have some drawbacks, such as low catalytic activity, difficult recovery of catalyst, long reaction time, incapable of a broad range of some substrates and so on. Therefore, the development of a simple, economic, efficient and environmental process for these compounds synthesis is of great significance in both practice and theory.The main objective of this dissertation is to perform the oxidations of sulfides to sulfoxides or sulfones, thiols to disulfides, alcohols to carbonyl compounds, benzylic halides to aromatic aldehydes or ketones, olefins to epoxides using hydrogen peroxide as an oxidant with a view to develop new environment-friendly methods and the specific research contents include the following aspects.A selective and efficient procedure for the oxidation of various sulfides with30%hydrogen peroxide catalyzed with sodium tungstate dihydrate in the presence of trioctylmethylammonium dihydrogen phosphate as PTC, respectively, to the corresponding sulfoxides or sulfones is developed. The oxidation reaction is carried out at-5℃to0℃in the presence of hydroxypropyl-β-cyclodextrins for sulfoxides or at50℃to60℃for sulfones. The mild reaction conditions, easy workup, and good yields of the products are the major advantages of this method.A green, straightforward and novel method for the oxidation of thiols to the corresponding disulfides is developed using hydrogen peroxide catalyzed by tetrabutylammonium iodide (TBAI) in water at room temperature. Compared with the former catalytic oxidation system, this method had some merits such as easy-operation, short reaction time and excellent yields.A new triple site phosphotungstate is used as isolated catalyst in the oxidation of alcohols, and the effect of reaction conditions on the catalytic reaction is investigated. It is found that a new oxidation reaction system using hydrogen peroxide in combination with TBAP has been developed, which is capable of converting alcohols into the corresponding carbonyl compounds in good to excellent isolated yields. Moreover this catalyst could be easily recovered by simple workup and reused up without any appreciable loss of its activity. Mild reaction conditions, good to high yields, stability, easy isolation of the compounds, good thermoregulated biphasic behavior and excellent recyclability of the catalyst are the attractive features of this methodology.A novel procedure for the oxidation of benzyl halides to the corresponding carbonyl compounds with hydrogen peroxide catalyzed by2,2,6,6-tetramethyl-l-piperidinyloxy (TEMPO) in water is developed. The oxidation mechanism and the effects of reaction factors are examined. This procedure includes many advantages such as mild reaction conditions, simplicity of operation, good to high yields. The results demonstrate that NaBr as co-catalyst is crucial to realize the oxidation of benzylic halides to aldehydes or ketones. It can shorten reaction time greatly. Benzyl bromide and their derivative show higher reactivity than benzyl chloride and their derivative without the addition of NaBr.A new schiff based complex of iron ion (TPTTTI) is synthesized, and found that the catalyst could epoxidize olefins efficiently. The effects of reaction conditions such as the amount of catalyst and various oxidants, temperature and solvents on the catalytic reaction are investigated. The results show that TPTTTI demonstrate the good performance and a wide range of aromatic and aliphatic olefines are found to be applicable to the catalytic system. Addition of bipydine can efficiently diminish the over-oxidation of epoxidation product. Advantages of our procedure include simplicity of operation, mild condition, and good to better yields. A possible reaction pathway is proposed to explain the formation of epoxidize.更多还原