【作者】 李亮；

【导师】 闫海龙；

【作者基本信息】 重庆大学 ， 药学， 2015， 硕士

【摘要】 第一部分:手性开环冠醚催化剂的优化和催化剂库的建立手性开环冠醚催化剂是最近几年新兴的研究方向,受到很多化学家的关注,但目前对这一催化剂的认识和理解还停留在比较浅的阶段。本论文将围绕目前手性开环冠醚催化的瓶颈问题,如缺乏系统的研究、催化体系匮乏、有限的催化反应适用范围等方面,进行积极的探索,研究结果将为相关手性开环冠醚催化剂的设计、开发提供实验和理论支撑。基于我们已有的催化剂,我们发展了一系列具有新骨架的手性开环冠醚催化剂,丰富了现有的手性催化剂库。第二部分:二级砜的不对称β消除我们报道了一种合成手性二级砜的有效方法。在我们发展的手性开环冠醚催化剂作用下,通过不对称β消除实现了手性砜的合成(二级砜的动力学拆分)。我们以手性BINOL为骨架的阳离子催化剂,氟化钾为碱,将不同的消旋体底物进行拆分,得到很好的对映选择性(ee值最高为99%,S值327)。此外,我们初步研究了它的反应机理,氟负离子拔去S构型底物β位上的氢形成碳负离子,同时苯磺酰基离去生成α、β不饱和酮和未参与反应的R构型的产物。更多还原

【Abstract】 First part: optimization of the polyethertethered chiral catalyst and building the catalyst libraryRecently, many chemists are focus on the polyethertethered chiral catalyst, what is one of the popular research area. But so far, the understanding of catalyst is still stay in the relatively shallow stage. This dissertation will surround the bottleneck of polyethertethered chiral catalyst to explore actively, such as: lack of systemic research, lack of Catalytic systems, limited scope of catalytic reaction and so on. It will be provide experimental and theoretical support to the design and development of polyethertethered chiral catalyst. Based on the existing catalyst, we have developed a series of novel polyethertethered chiral catalyst through different substituents at the 3,3’-positions of the BINOL unit to enrich the existing chiral catalyst library. Second part: Asymmetric β-Elimination of Secondary SulfonesThe asymmetric synthesis of secondary sulfones by a highly enantioselective β-elimination(kinetic resolution of secondary sulfones) catalyzed by chiral cation-binding polyether is reported. This transformation employs BINOL based polyether as the cation-binding catalyst and readily available potassium fluoride as the base, which is compatible with different substituted racemic sulfones and could provide an access to the preparation of enantiopure secondary sulfones in excellent enantioselectivity(ee value up to 99%, S factor up to 327). Preliminary mechanistic studies suggest that the reaction proceeds via a carbanion mechanism, involving initial β-proton-elimination by fluoride ion to afford β-carbanion intermediate and the consequent loss of Ph SO2- from α-carbon atom yields the olefinic product and unreacted enantiopure sulfones.更多还原