共查询到19条相似文献,搜索用时 62 毫秒
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树状大分子作为一类组成精确的超支化结构大分子,近十多年来引起了科学家们的广泛关注.作为一类新型可溶性载体应用于均相催化剂,尤其是手性均相催化剂的负载化研究是树状大分子的重要应用领域之一.本文主要介绍了手性树状大分子膦配体,包括膦配体位于树状分子核心、末端和表面的几种类型,重点对它们与金属配合物形成的催化剂在不对称催化氢化反应中的应用研究进行总结,同时对负载催化剂的分离与回收、树状分子载体的结构和体积对催化剂性能的影响进行了讨论. 相似文献
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β-环糊精衍生的手性氧膦配体在烯烃不对称氢甲酰化反应中的应用徐小红周宏英陈静傅宏祥1)(中国科学院兰州化学物理研究所兰州730000)关键词β-环糊精手性膦配体不对称氢甲酰化铑催化剂分类号O643.32糖是一类含有丰富的手性碳原子的天然化合物,一些单... 相似文献
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近三十年来,人们对光学异构体在药物、食品添加剂、昆虫信息素、农药和香料等领域中的应用做了广泛地研究,结果表明,在大多数情况下,光学异构体的性质不尽相同,其差别表现为1>生物活性不同;2>转运机制不同;3>可能的代谢途径不同。这样如何获得一种单一构型的光学异构体就成为化学家研究的重点课题。不对称反应的发现和近年来取得的成就为获得单一构型的光学异构体提供了一条简捷而经济的途径。手性过渡金属络合物催化的不对称反应人 相似文献
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手性膦配体及其不对称催化的研究进展①徐小红吕士杰傅宏祥(中国科学院兰州化学物理研究所,兰州730000)关键词膦配体手性配体不对称催化1前言手性是宇宙间的普遍特性,在生命的产生和演变过程中,自然界往往对一种手性有所偏爱.如:自然界存在的糖为D构型,氨... 相似文献
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手性烯烃配体是一类具有重要应用前景的新型配体,自发展以来就引起化学家们的广泛关注.手性烯烃配体在一些反应中表现出比传统氮、磷、氧配体更高的活性和选择性,实现了一些使用其它类型配体不能实现的化学转化.为了增强手性烯烃配体与金属的配位能力,化学家们在其骨架上引入杂原子,发展得到混合型的烯烃配体,增加了配体的多样性,对进一步拓展手性烯烃配体的类型和应用具有非常重要的意义.目前关于手性烯烃配体已经有一些综述,本综述将着重介绍最近几年来发展的手性开链双烯配体、手性膦烯烃配体和手性硫烯烃配体及其在过渡金属催化的不对称反应领域的应用. 相似文献
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几种自制手性配体及其在不对称催化中的应用吕士杰王来来(中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室兰州730000)关键词手性配体不对称羰基化不对称烷基化分类号0643.32不对称催化的核心问题是手性催化剂的设计与合成.绝大多数手性催... 相似文献
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Prof. Dr. Zhi-Yong Han Prof. Dr. Liu-Zhu Gong 《Chemical record (New York, N.Y.)》2023,23(4):e202300049
Asymmetric Brønsted acid catalysis has been recognized as a powerful concept for asymmetric synthesis. In the process of pursuing more robust and highly effective chiral Brønsted acid catalysts, chiral bisphosphoric acids have received much attention in the last two decades. Their unique catalytic properties are mainly attributed to the inherent intramolecular hydrogen bonding interactions that could increase the overall acidity and tune the conformation property. Integrating hydrogen bonding into the catalyst design, quite a few structurally unique and effective bisphosphoric acids have been synthesized, which frequently exhibited superior selectivity in a broad range of asymmetric transformations. This review summarizes the status quo of chiral bisphosphoric acid catalysts and their applications in catalyzing asymmetric transformations. 相似文献
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《化学:亚洲杂志》2018,13(19):2829-2833
Asymmetric addition of diarylphosphines to oxa‐ and azabicyclic alkenes proceeded in the presence of a chiral phosphapalladacycle catalyst and a mild acid at room temperature to give exclusively the enantioenriched addition products in excellent yields and good selectivities. Three new chiral carbon centers were generated stereoselectively by the catalytic hydrophosphination reaction. 相似文献
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Jinguo Long Rongrong Yu Jihui Gao Xianjie Fang 《Angewandte Chemie (International ed. in English)》2020,59(17):6785-6789
Enantioselective auto‐tandem catalysis represents a challenging yet highlight attractive topic in the field of asymmetric catalysis. In this context, we describe a dual catalytic cycle that merges allylic cyanation and asymmetric hydrocyanation. The one‐pot conversion of a broad array of allylic alcohols into their corresponding 1,3‐dinitriles proceeds in good yield with high enantioselectivity. The products are densely functionalized and can be easily transformed to chiral diamines, dinitriles, diesters, and piperidines. Mechanistic studies clearly support a novel sequential cyanation/hydrocyanation pathway. 相似文献
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手性金属Salen配合物在不对称催化中的应用* 总被引:9,自引:3,他引:9
手性Salen金属配合物已在不对称催化中得到了广泛的应用。本文主要介绍了可溶性的手性金属Salen配合物在不对称催化反应中的应用以及手性金属Salen配合物固载化研究取得的进展。 相似文献
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Qifeng Lin Longji Li Prof. Dr. Sanzhong Luo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(43):10033-10044
Asymmetric electrochemical catalysis, an emerging frontline in asymmetric catalysis and electro-organic synthesis, is summarized. Representative works are classified, with respect to the external chiral resources, including chiral media, chiral mediator, chiral catalyst, and chiral electrode. This concept article is expected to provide readers with the general concepts and perspectives of each chiral electrochemical catalysis mode, and to indicate the potential and future development of asymmetric electrochemical catalysis. 相似文献
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Remarkably high asymmetric amplifications (positive nonlinear effects) were realized in some chiral lanthanide complex-catalyzed organic reactions such as the asymmetric hetero-Diels–Alder reaction, Michael addition reaction, epoxidation, etc. These phenomena may be explained by the autogenetic formation of the enantiopure lanthanide complexes as the most active catalysts. The high coordination numbers of the lanthanides seem to play an important role through the formation of aggregates of the heterochiral complexes as less active catalysts. 相似文献