【作者】 张敏；

【导师】 张文珍；

【作者基本信息】 大连理工大学 ， 化学工程（专业学位）， 2020， 硕士

【摘要】 二氧化碳是全球碳循环的重要组成部分,为碳的最高氧化态,具有极高的稳定性。二氧化碳是安全、简单易得的可再生资源,利用二氧化碳合成高附加值的精细化工产品是绿色化学中的研究热点。鉴于二氧化碳结构的特殊性,利用二氧化碳合成羧酸化合物的研究由来已久,而二氧化碳的反应惰性往往需要苛刻的反应条件,二氧化碳参与合成手性羧酸化合物的研究鲜有报道。手性羧酸化合物广泛存在于药物分子、天然产物、生物活性分子中,因此开发一种二氧化碳参与的合成手性羧酸化合物的方法具有重要的研究意义。电化学有机合成是通过在反应中施加电压或电流,利用电子作为反应试剂实现化学反应,是一种可持续的氧化还原反应。电化学只需要控制电极电势就可以获得高活性的反应中间体,反应条件温和高效。手性金属络合物参与的二氧化碳不对称催化反应是获得手性羧酸化合物的重要途径,往往需要化学计量的还原试剂。将有机电化学合成与不对称催化相结合能避免氧化还原试剂的使用,是当前电化学有机合成的前沿领域。本论文主要研究电化学驱动的金属络合物催化的不对称羧化反应合成手性2-芳基丙酸化合物。论文首先利用电化学技术研究了几种手性Salen金属络合物的电化学行为,发现以Ag/AgI为参比电极时,手性双SalenCo配合物表现出良好的不对称催化潜力。接着研究了二氧化碳和反应底物1-氯-1-苯乙烷对（S,S）-SalenCo（II）的电化学行为的影响,对反应中间体和反应机理进行了分析,观察到手性金属络合物[PhCH（CH₃）SalenCo（II）]^-的形成是实现不对称羧化反应的关键。在恒电流和恒电压条件下分别进行了1-氯-1-苯乙烷的不对称羧化反应,研究了手性催化剂结构、阴极材料、反应温度、电解电位和电流密度对反应产率和对映体选择性的影响,在使用手性双SalenCo催化剂的最优条件下,2-苯基丙酸的ee值可达77%。同时进一步研究了缺电子底物的电化学行为和不对称电羧化反应。羰基硫是一种具有危害性的含硫气体,本论文也设计构建了催化剂量碱促进的苯基炔腙与羰基硫的环化反应体系合成噻二嗪-2-酮类化合物。通过对碱、碱用量、溶剂等反应条件的考察,优化出最优反应条件:0.1当量的Cs₂CO₃为碱,CH₃CN为溶剂,在60^oC下反应12小时,噻二嗪-2-酮的产率最高可达77%。底物适应性考察发现富电子底物的产率显著高于缺电子底物。更多还原

【Abstract】 Carbon dioxide is an important part of the global carbon cycle,and it has extremely high stability with highest oxidation state of carbon.At the same time,carbon dioxide is a safe and easily available renewable resource.The use of carbon dioxide to synthesize high value-added fine chemical products is a research hotspot in green chemistry.Due to the special structure of the carbon dioxide,the synthesis of carboxylic acid compounds using carbon dioxide has a long history.The reaction of carbon dioxide often requires harsh conditions,and studies on the synthesis of chiral carboxylic acid compounds using carbon dioxide are rarely reported.Chiral carboxylic acid compounds are widely present in medicines,natural products,and biologically active molecules.Therefore,it is highly desirabale to develop a method for synthesizing chiral carboxylic acid compounds with carbon dioxide.Electrochemical organic synthesis is a sustainable redox reaction by applying voltage or current to the reaction and using electrons as a reagent to drive the chemical reaction.Electrochemistry only needs to control the electrode potential to obtain highly active reaction intermediates,with mild and efficient reaction conditions.The asymmetric catalytic reaction of carbon dioxide catalyzed by chiral metal complexes is an important way to obtain chiral carboxylic acid compounds.However,stoichiometric reductive reagents are often required.Combining organic electrochemical synthesis with asymmetric catalysis can avoid the use of reductive reagents and is the frontier field of electrochemical organic synthesis.In this paper,we have developed an electrochemically driven metal complex catalyzed asymmetric carboxylation to synthesize chiral 2-arylpropionic acid compounds.In this thesis,the electrochemical behavior of several chiral Salen metal complexes was studied by electrochemical techniques.When Ag/AgI was used as the reference electrode,chiral biSalenCo complexes showed good asymmetric catalytic potential.Then the effect of carbon dioxide and the reaction substrate 1-chloro-1-benzeneethane on the electrochemical behavior of（S,S）-SalenCo（II）was studied.Through the analysis of reaction intermediates and reaction mechanism,it was observed that the formation of chiral metal complex[PhCH（CH₃）SalenCo（II）]^-is the key to the realization of asymmetric carboxylation.We carried out asymmetric carboxylation of 1-chloro-1-phenylethane under constant current and constant voltage conditions,and investigated the chiral catalyst,cathode material,reaction temperature,electrolytic potential and current density on the reaction yield.Under optimal conditions using chiral biSalenCo（II）catalyst,the enantiomeric excess of 2-phenylpropionic acid can reach 77%.At the same time,we further studied the electrochemical behavior and the asymmetric electrocarboxy-lation reaction of the electron-deficient substrate.Carbonyl sulfide is a hazardous sulfur-containing gas.We also developed a base-promoted cyclization reaction of phenylyne hydrazone with carbonyl sulfur,to synthesize thiadiazine-2-one compounds.Through the investigation of the reaction conditions such as base,amount of base and solvent,the obtained the optimal reaction conditions are:0.1equivalent of Cs₂CO₃ as the base,CH₃CN as the solvent and reacted at 60 ^oC for 12 hours.Under optimal conditions,the yield of thiadiazin-2-one can reach up to 77%.The yield of the electron-rich substrate was significantly higher than that of the electron-deficient substrate,and a variety of thiadiazine-2-one compounds were synthesized.更多还原