手性铑催化剂在不对称氢转移、串联反应中的应用及其负载催化活性研究

发布时间：2018-02-24 01:11

本文关键词： 串联反应不对称氢转移手性负载型铑催化剂疏水性　出处：《上海师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：在医药,农药和精细化工品的生产中,不对称氢转移(ATH)有着广泛应用,其被认为是构建手性醇类和手性胺类的最有效途径。不对称氢转移反应,取代了氢气作为氢源,因而具有条件温和、操作便捷等很多优点,发展迅猛。在催化,吸附,生物医学和传感器领域,以及有机功能化的介孔材料等方面受到广泛关注,自从发现疏水性介孔硅材料可以提高催化反应速率、提高其水热稳定性、以及其对有机分子的吸附效率,使得其得到广泛关注。(1)目前大多数都是通过对苯乙酮类化合物加压氢化得到手性苯乙醇,虽然能得到高收益和高立体选择性的目标化合物,但高压的反应使得操作较难。另外纯原料芳磺酰基甲基苯乙酮也需要是从苄溴苯乙酮和芳亚磺酸钠发生亲核取代反应生成得到,这样使得生产周期长、产品成本高。本章以苄溴苯乙/丙酮和对甲基苯亚磺酸钠为底物,筛选了合成中间产物芳磺酰基甲基苯乙酮的反应条件,以及一锅串联合成手性芳磺酰基甲基苯乙/丙醇的最佳催化剂;然后通过一锅催化多步有机反应,以甲酸钠为氢源,以对位/间位苄溴苯乙/丙酮和芳亚磺酸钠为底物,通过一锅串联不对称氢转移合成手性目标产物。克服了一锅中串联反应条件的外在冲突问题,磺酰基团也可以离去而不发生外消旋化。(2)以N,N,N-三甲基-1-十六烷基溴化铵为硬模板,以四乙基硅酸酯为主要骨架硅源,以(S,S)-4-(三甲氧基硅烷基)苯磺酰基-1,2-二苯基二胺为手性功能硅源,同时以二氯二苯基硅源为疏水功能硅源,来制备疏水性介孔催化剂前体,然后配位五甲基环戊二烯基氯化铑,成功制备疏水性铑功能化催化剂。通过一系列对催化剂的表征,证明成功合成了目标催化剂;以及将其应用到2-芳基乙酰基苯甲酸乙酯的不对称催化反应中,其表现出良好的催化活性和立体选择性;另外该催化剂易回收且结构稳定,重复使用八次未见活性有明显降低。
[Abstract]:Asymmetric hydrogen transfer (ATH) is widely used in the production of pharmaceuticals, pesticides and fine chemicals. It is considered to be the most effective way to construct chiral alcohols and chiral amines. Therefore, it has many advantages, such as mild conditions, convenient operation and so on. It has developed rapidly. It has received extensive attention in the fields of catalysis, adsorption, biomedicine and sensor, and organic functional mesoporous materials, etc. Since it was found that hydrophobic mesoporous silicon can increase the rate of catalytic reaction, improve its hydrothermal stability, and its adsorption efficiency for organic molecules, Most of them are produced by hydrogenation of acetophenone compounds under pressure to produce chiral phenylethanol, although they can obtain target compounds with high profit and high stereoselectivity. In addition, the pure raw material aryl sulfonyl methyl acetophenone also needs to be obtained from the nucleophilic substitution reaction between benzyl bromide acetophenone and sodium aryl sulfonate, which makes the production cycle long. In this chapter, benzyl bromophenyl ethylacetone and sodium p-methylphenylene sulfonate were used as the substrates, and the reaction conditions for the synthesis of the intermediate product aryl sulfonyl methyl acetophenone were screened. And the best catalyst for the synthesis of chiral aryl sulfonyl methyl phenyl ethylbenzene / propanol in one pot in series, and then through one pot catalytic multistep organic reaction with sodium formate as the hydrogen source, para-position / m-benzyl bromophenyl ethyl / acetone and sodium aryl sulfonate as the substrates, The chiral target product was synthesized by one-pot series asymmetric hydrogen transfer. The external conflict problem of series reaction conditions in one pot was overcome. The sulfonyl group can also leave without racemization. The hydrophobic mesoporous catalyst precursor was prepared by using tetraethyl silicates as the main skeleton silicon source, Sphthoxy-4-( trimethoxysilyl) benzenesulfonyl-2-diphenyl diamine as chiral functional silicon source and dichlorodiphenyl silicon as hydrophobic functional silicon source. The hydrophobic rhodium functional catalyst was successfully prepared by the coordination of pentamethylcyclopentadienyl rhodium chloride. A series of characterization of the catalyst proved that the target catalyst was successfully synthesized. The catalyst showed good catalytic activity and stereoselectivity in the asymmetric catalytic reaction of ethyl 2-arylacetylbenzoate. In addition, the catalyst was easy to be recovered and its structure was stable.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

【相似文献】