【作者】 韩邦友；

【导师】 欧阳平凯； 朱红军；

【作者基本信息】 南京工业大学 ， 生物化工， 2004， 博士

【摘要】 光学活性氰醇的不对称催化合成对合成具有光学活性的新型医药、农药产品有着十分重要的意义,其中(S)-α-氰基-3-苯氧基苯甲醇是合成一系列光学活性拟除虫菊酯如溴氰菊酯、氰戊菊酯等的重要中间体,研究其不对称合成的成熟方法是制取高光学纯度拟除虫菊酯杀虫剂的关键。本文对光学活性的手性海因、手性环二肽的制备及其对不对称氰醇化催化的作用进行了研究,将所制备的多种手性海因、手性环二肽应用于 3-苯氧基苯甲醛的不对称氰醇化反应,考察了此类催化剂的对映选择性;同时,结合工业生产实际,对此类光学活性催化剂在“酰氯-醚醛一锅法”生产氰戊菊酯工艺中的不对称诱导效能进行了研究,具有一定的理论和实际应用价值。首先,在参阅文献和实验探索的基础上,研究了由氨基酸为起始原料制备3,5-二取代手性海因的合成工艺。系列氨基酸分别与异氰酸苯酯(异氰酸苄酯)经缩合、环化反应得到十种手性海因化合物(5S or 5R)-5-(5-取代)-3-苯基-2,4-咪唑啉二酮(1a、1b、1c、1d、1e、1f、1g、1h、1i、1j),它们均具有光学活性,经元素分析、IR 及 HNMR、13CNMR 分析证实其结构与预期结构吻合。并对文1献报道的水相缩合体系作了改进,确定了水-水溶性有机溶剂的均相缩合体系,使缩合产物与副产物二芳基脲得到有效分离,保证了最终环化产物的纯度。详细探讨了原料配比、溶液 pH 值、反应温度、反应时间等合成条件对制备手性海因实验结果的影响;确定了缩合反应的 pH 值比相应的氨基酸的等电点约大1.5-2.0,异氰酸酯:氨基酸的摩尔比在 1.2-1.4 时较好,环化时间以 3.5-4h 为佳。结果表明,改进后的手性海因制备工艺,反应迅速,产品色泽好,产率达75%。其中,所合成的十个手性海因化合物中的 1c、1d 化合物未见文献报道。研究了由 L-苯丙氨酸(D-苯丙氨酸、L-亮氨酸)、L-组氨酸(D-组氨酸)为起始原料,通过对苯丙氨酸(亮氨酸)氨基保护,对组氨酸羧基保护,接肽,加氢脱保护基,甲醇回流成环制备手性环二肽的合成工艺,得到一系列结构类似的手性环二肽化合物。所合成的环二肽系列化合物及前体 2b、2c、2d、2e、2f、2g、2h 均具有一定的光学活性,经熔点测定、元素分析、IR 及 HNMR、13CNMR 分析证 1实其结构与预期结构一致。并对混合酸酐法和活泼酯法进行对比试验,详细探讨 I<WP=4>韩邦友:手性海因、环二肽的合成及不对称氰醇化研究 2004 年 5 月了原料配比、反应物浓度、反应温度、加氢脱苄时间、回流环化时间等合成条件对手性环二肽制备实验结果的影响;特别是对手性环二肽的结晶形态、活性碳吸附固载进行了研究,保证了最终环化产物的纯度及产品的不对称诱导效能。在多次试验的基础上,结合江苏快达农化股份有限公司的光气资源优势,对活泼酯法的合成技术进行了改进,用光气代替三氯氧磷、用固碱代替液碱。结果表明,改进后的手性环二肽制备方法,工艺简单、收率高、污染少、原料易得、成本低,利于工业化,产率可达 65%,优于混合酸酐法,该项技术发明已申请了我国发明专利。为了研究本文所制备的手性海因的催化活性,首先考察了它们在 3-苯氧基苯甲醛不对称氰醇化中的诱导作用,并对氰醇化加成反应条件作了初步探讨。实验证明,手性海因 1e、1f、1g、1h、1i 在此反应中均具有一定的催化活性;其中 1e 的对映选择性较高,所得氰醇 e.e.值达 35.5%;1i 的选择性较低,为 6.1%。它们的不对称诱导效能依次是 1e>1f>1h>1g>1i。并且证实:(R)-型手性海因能够催化(S)-构型氰醇(如 4b),(S)-型手性海因能够催化(R)-构型氰醇(如4a),与有关文献报道结果一致。为了进一步考察手性海因在不同反应体系中的不对称诱导活性,我们结合江苏快达农化股份有限公司的“酰氯-醚醛一锅法”法生产氰戊菊酯工艺,进行了手性海因催化合成(S,S)-氰戊菊酯的应用试验,旨在初步探索其工业化生产条件下的催化活性。试验表明,手性海因 1a、1b、1c、1d、1e、1f、1g、1h、1i、1j 在“酰氯-醚醛一锅法”生产氰戊菊酯反应过程中,都有一定的催化活性,其中 1e、1f、1g、1h、1i 表现出了与在氰醇化反应中几乎相同的对映选择性,其对映选择性为:1e>1f>1h>1g>1i。其中使用(S)-型催化剂 1e 所得(S,R)-氰戊菊酯 5e 的 e.e.值仍高达 34.1%, 使用(R)-型催化剂 1f 所得(S,S)-氰戊菊酯 5f 的 e.e.值为 21.7%。对所制备的手性环二肽催化剂在“酰氯-醚醛一锅法”生产(S,S)-氰戊菊酯的不对称催化作用进行研究,并对不对称氰醇化加成反应条件、不对称催化机理作了初步探讨。实验证明:手性环二肽 2e、2f、2h 在此反应中均具有一定的催化活性;其中 2f 的对映选择性较高,所得(S,S)--氰戊菊酯含量为:87.56%,对映体 e.e.值高达 83.1%,超过国外生产(S,S)-氰戊菊酯的水平(S,S-氰戊菊酯 II<WP=5>南京工业大学博士学位论文含量≥75%);环(D-苯丙-D-组)与环(L-亮-L-组)不对称氰醇化所得氰戊菊酯的手性一致,与环(L-苯丙-L-组)的催化效果相反。它们的不对称诱导效能与催化剂的形态、CN-的来源、溶剂的种类、催化剂用量、反应时间有很大的关系,其中催化剂的形态和 CN-的来源影响较大。胶状?更多还原

【Abstract】 Asymmetric synthesis of optically active cyanohydrins is very important to thedevelopment of medical and agrochemical products, while chiral hydantoins andchiral cyclic dipeptides are the effective asymmetric catalysts for synthesis of them.For example, (S)-α-cyano-3-phenoxybenzylalcohol is an important precursor forsynthesis of a series of optically active pyrethroids such as deltamethrin andfenvalerate. Asymmetric synthesis of chiral cyanohydrins is the key step to producechiral pyrethroids with high optical activity. First of all, the enantioselectivity of theprepared chiral hydantoins and chiral cyclic dipeptides was mainly studied byapplication them to asymmetric cyanohydrination of 3-phenoxy benzaldehyde.Second, in connection with industrialization process, the asymmetric catalytic efficacyof these catalysts was also observed in the synthesis of fenvalerate by reaction ofbutylric acid chloride and 3-phenoxyphenylaldehyde, which have practical andtheoretical value.The methods of preparation of 3,5-disubstituted chiral hydantoins from aminoacids were been studied. A series of chiral hydantoin compounds[ (5S or5R)-5-(5-substituted) -3-phenyl-2,4- imidazolidinedione, 1a,1b,1c,1d,1e,1f,1g,1h,1iand 1j], were obtained by condensation and cyclization of amino acids with phenylisocyanates or benzyl isocyanates. These ten kinds of hydantoin all have opticalactivity and have been identified by elementary analysis, IR, HNMR and 1 13 CNMR.Some improvements were made in condensation reactions, such as mixed solventswere used instead of water alone and an effective method of separating condensationproduct and by-product (diarylurea), which ensured hydantoins with high purity.And effects of the ratio of raw materials, pH value of solution, reaction temperatureand reaction time et al on preparation of chiral hydantoins, have been discussed indetail. These studies led to the conclusion that, optimally, the reaction should be run atthe pH of condensation 1.5-2.0 high than the isoelectrics point of amino acid, molarratio of isocyanates to amino acids is about 1.2-1.4, the cyclization reaction time isbetween 3.5-4h. The result of the experiment indicated that, the improved process ofchiral hydantoin preparation has many advantages, such as rapid reaction, betterproduct and higher yield of 75%. The products 1c and 1d had not been reportedbefore.The process of preparation of cyclic dipeptides from L-phenylalanine (D-phenylalanine , L-leucine) and L-histidine ( as the raw materials) was studied. The i<WP=7>韩邦友:手性海因、环二肽的合成及不对称氰醇化研究 2004 年 5 月peptide was linked after protection of amino group in phenylalanine (leucine) andcarboxyl group in histidine, then the protective group was removed by hydrogenation,cyclization was completed under refluxing in methanol. As a result, a series of chiralcyclic dipeptides were obtained. The prepared cyclic dipeptides and their precursorswhich all have certain optical activity have been identified to be the expectedstructures by m.p., elementary analysis, IR, HNMR and CNMR. The two methods 1 13of preparation of chiral cyclodipeptides, such as "mixed anhydrides" and "activeesters" were been studied. And effects of the molar ratio of raw materials,concentration of reactants, reaction temperature, reaction time et al., have beenstudied in detail. Especially, the crystal form of cyclic dipeptides and absorption byactive carbon were studied, so that the purity and asymmetric catalytic effectivenessof target product was good. With study of many experiments and in order to takeadvantage of phosgene in Jiangsu Kuaida Agrochemical Co., Ltd. improvement wasmade in active esterification in which liquid alkaline was replaced by solid alkalineand phosphorus oxychloride was replaced by phosgene. The result of the experimentshowed that with higher yield of 65%, less pollution, easily obtained raw materials,low cost, the simplified process was easier to industrialize than更多还原