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一类聚丙烯腈类高分子聚合物负载金鸡纳碱衍生伯胺催化剂的合成及其在不对称反应中的应用

Synthesis of Polyacrylonitrile Polymers-Supported 9-Amino Cinchona Alkaloids Catalysts and Their Applications in the Asymmetric Reaction

【作者】 周禁钦

【导师】 马学兵;

【作者基本信息】 西南大学 , 有机化学, 2011, 硕士

【摘要】 人们对于金鸡纳碱的研究已经几十年了,由于金鸡纳碱具有优良的刚性骨架和良好的催化活性位点,它常被用于不对称催化反应的诱导配体,而且表现出优异的催化性能。金鸡纳碱C9上羟基表现出的活性引人关注,1995年德国的Henri Brunner等人改进了前人的工作,在金鸡纳碱的C9位点上引入氨基结构,开启了9-氨基金鸡纳碱衍生物研究的先河。本文以廉价易得的辛可尼定(CD)为起始原料,将9-羟基用氨基进行取代,同时发生伞转效应合成9-氨基金鸡纳碱衍生物1,再将其与丙烯腈进行不同比例的聚合,使之成为聚丙烯睛类高分子聚合物锚定金鸡纳碱衍生伯胺催化剂,实现了将金鸡纳碱衍生物负载到聚丙烯腈类高分子上本文合成的聚丙烯腈类高分子负载金鸡纳碱伯胺催化剂2a-d,通过核磁共振(NMR)、傅立叶变换红外光谱(FT-IR)、热重分析(TG)、X-射线粉末衍射(XPRD)、N2-吸附脱附比表面仪、透射电镜(TEM)和扫描电镜(SEM)等手段,对其组成、结构和表面形貌进行了表征。将负载金鸡纳碱伯胺催化剂2a-d应用于苯甲醛及其衍生物与环己酮和环戊酮的不对称Aldol反应,探讨了催化反应的最佳实验条件。在25℃、2 mL水中、7.5mol%2a作催化剂条件下,反应96 h,对硝基苯甲醛与环己酮的Aldol反应能达到95.8%收率、96.4%ee的对映选择性和90/10的dr值。反应结束后,通过过滤实现催化剂的回收和重复使用,但重复四次后,产率、ee值和dr值都明显降低。

【Abstract】 Cinchona alkaloids had been researched and attracted people’s attention for decades. Due to its rigid frame and active sites, it was widely applied in asymmetric catalytic reactions with excellent catalytic properties. In 1995, Henri Brunner introduced amino-group instead of hydroxyl group in C9 of cinchona alkaloids, and opened the door of research 9-amino cinchona alkaloids derivatives in asymmetric catalytic reactions.In this thesis, the low-cost and facile cinchonidine as the raw material,9-hydroxyl group was substituted by 9-amino group with simultaneous Walden inversion to give 9-amino cinchona alkaloid 1. Polyacrylonitrile polymer-supported cinchona alkaloid primaryamine cataysts 2a-d were prepared by reaction of the obtained 9-amino cinchona alkaloid 1 with acrylonitrile in different molar ratioes for the first time.The structures and surface morphologies of polymer catalysts 2a-d had been characterized by NMR, FT-IR, TG, XPRD, N2 adsorption-desorption isothermal curve, TEM and SEM.The synthesized catalysts 2a-d were applied in the asymmetric Aldol reaction of p-nitroben-zaldehyde with cyclohexanone, and the optimum experimental conditions were screened in details. The product 5a in 95.8% yield,96.4% ee and 90/10 dr was obtained at 25℃for 96 h in 2 mL water and 7.5 mol% catalyst 2a. After the reaction was completed, the catalyst 2a could be recovered by filtration and reused in the asymmetric Aldol reaction. However, yield, ee and dr were reduced sharply after fourth recycled times.

  • 【网络出版投稿人】 西南大学
  • 【网络出版年期】2011年 09期
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