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1.
基于连续流微通道反应器,在温和条件下首次实现了铜催化格氏试剂的不对称烯丙基烷基化反应.在-20~-10℃条件下,用双流路不锈钢折线型连续流微通道反应器,以极短的保留时间0.6 s,实现了铜催化的不同格氏试剂的不对称烯丙基烷基化反应,获得的产物收率为82%~99%, ee值中等至良好.此外,在连续流反应条件下连续进料34min,放大(S)-3-甲基-1-环己烯的合成规模,获得0.968 g的(S)-3-甲基-1-环己烯,收率为98.7%, ee值为96.6%,证明了在连续流条件下铜催化剂可以稳定地催化格氏试剂发生不对称烯丙基烷基化反应.  相似文献   

2.
固定化酶微反应器是将生物分子固定技术与生化微反应相结合制备的一种固定化催化装置。这种微型化的反应系统由于兼具固定化酶的特异性催化、可重复利用及微分析的低消耗、易分离等优点,在生命科学如蛋白质组学、酶抑制剂的筛选、生物催化等领域具有非常重要的作用。固定化酶微反应器的性能与其制作方法关系密切。本文着重从酶与固定化载体结合方式的角度,对近年来固定化酶微反应器的各种制备方法和应用进行了较为详细的评述。重点讨论了各种方法的优缺点和最新的发展情况,并对其发展前景进行了展望。  相似文献   

3.
手性相转移催化是不对称催化领域的重要分支之一,扮演着越来越重要的角色。本论文综述了几类新型手性季鏻盐催化剂的设计合成,及其在催化不对称Henry反应、不对称氢磷酰化反应、不对称烷基化反应、不对称Michael加成反应、不对称Mannich反应、不对称aldol反应、不对称质子化反应及不对称胺化反应中的催化活性和对映选择性,重点介绍了不同催化剂和反应底物之间立体效应和电子效应的影响,并对手性季鏻盐催化剂的发展进行了展望。  相似文献   

4.
通过在毛细管内层叠层组装纳米沸石并固定脂肪酶来构建纳米沸石修饰的固定化酶微反应器通道,将纳米沸石良好的生物相容性和高的酶固定能力与微反应器反应效率高、扩散传质快等优点相结合. 以对硝基苯棕榈酸酯的水解作为探针反应对该微反应器内固定化酶催化水解反应动力学进行了研究和计算,并与普通反应器内同样的反应进行比较. 通过对比米氏方程参数,证实在微反应器内酶催化水解反应效率可比普通反应器内提高3倍以上并可提高酶和反应底物的亲和能力.  相似文献   

5.
韩志勇  龚流柱 《化学进展》2018,30(5):505-512
有机小分子和金属联合催化是指用有机小分子和金属等多种催化剂同时或连续活化不同底物、官能团或中间体,从而完成催化反应。该策略可以实现单一催化剂无法完成的反应。根据催化剂活化模式的不同,有机小分子和金属联合催化可以分为协同催化、接力催化与连续催化。近年来,随着有机小分子催化的快速发展以及人们对金属和有机催化的理解越来越深入,有机小分子和金属联合催化方面的报道逐年增加,正在发展成为均相不对称催化中受到广泛关注的新兴研究领域。钯配合物是重要的过渡金属催化剂,钯催化在有机合成中具有十分广泛的应用。本文重点总结了钯和手性有机小分子联合不对称催化方面的进展,主要包括手性胺、手性布朗斯特酸以及手性亲核催化剂等有机催化剂与钯联合催化,同时指出了该领域内一些亟待解决的问题,并对未来的发展作了展望。  相似文献   

6.
有机催化不对称Henry加成反应   总被引:1,自引:0,他引:1  
有机催化不对称合成反应是目前国内外研究最为活跃的领域之一.不对称Henry反应是合成光学活性硝基化合物的有效手段,目前报道的催化不对称Henry反应的有机催化剂主要有手性胍、手性(硫)脲衍生物、金鸡纳碱衍生物等,取得了良好的催化活性和对映选择性.对各类有机催化剂在有机催化不对称Henry反应中的应用研究进展,以及不对称诱导反应的机理、催化剂的分子结构及反应条件对其催化活性和不对称诱导活性的影响进行了评述.  相似文献   

7.
上官莉  徐璇  刘松琴 《电化学》2019,25(3):302-311
研究酶的组装和催化反应不仅有利于探索生命活动的本质,同时对开发酶在工业合成、分析检测、疾病治疗等领域的实际应用价值具有重要的指导意义. 研究发现,酶的有效固定和有序组装是保持酶活性、酶促反应的稳定性和对酶催化过程进行控制的重要途径,而在纳米通道内进行单酶或多酶的有序组装,利用纳米通道的限域效应可有效保持酶的构型进而提高酶催化反应的选择性和催化效率,增强酶级联反应的动力学进程. 本文概述了近年来基于纳米通道的酶反应器在生物传感领域的研究进展,着重描述纳米通道限域空腔内酶的组装方法、酶催化反应及其动力学机制,并展望了基于纳米通道的酶反应器的应用前景.  相似文献   

8.
过渡金属催化是现代有机合成化学中精准构建化学键最重要的工具之一.有机小分子催化是21世纪初开始蓬勃发展的一个新兴研究领域.两者在不对称烯丙基化反应中的完美结合有意义地解决了该领域亲核试剂的普适性、立体选择性控制等挑战性问题.本文综述了过渡金属与有机小分子协同催化的不对称烯丙基化反应研究进展.按照不同的手性控制方式(过渡金属催化剂控制手性、有机小分子催化剂控制手性以及两者共同控制手性)对这些反应进行了梳理和总结,同时对代表性反应的机理以及该领域仍然存在的问题与未来发展进行了简单阐述.  相似文献   

9.
艾林  肖季川  申秀民  张聪 《有机化学》2005,25(11):1319-1333
手性二胺作为具有良好催化活性和对映选择性的手性配体或手性辅助剂, 在多种催化不对称反应中已经得到广泛应用, 并取到了很好的研究成果. 目前, 手性二胺化学的研究已成为催化不对称化学领域中一个十分活跃和引人注目的研究热点. 综述了手性二胺化学近几年的研究进展.  相似文献   

10.
采用简单、新颖的沸石粒子引入方法,将NaX沸石晶种引入不锈钢微反应器的微通道内,并用流动法"就地"直接在微通道内通过沸石生长形成NaX沸石膜层,经铯离子交换处理成为CsNaX催化层,用苯甲醛和氰基乙酸乙酯的Knoevenagel缩合反应评价了该催化层的催化性能.结果表明,微通道内形成的沸石膜层连续,均匀,具有良好的催化功能.微反应器内缩合反应的结果明显优于传统反应器.  相似文献   

11.
Asymmetric gold catalysis has been rapidly developed in the past ten years. Breakthroughs have been made by rational design and meticulous selection of chiral ligands. This review summarizes newly developed gold-catalyzed enantioselective organic transformations and recent progress in ligand design (since 2016), organized according to different types of chiral ligands, including bisphosphine ligands, monophosphine ligands, phosphite-derived ligands, and N-heterocyclic carbene ligands for asymmetric gold(I) catalysis as well as heterocyclic carbene ligands and oxazoline ligands for asymmetric gold(III) catalysis.  相似文献   

12.
Synergistic Pd/Cu catalysis has been utilized in the Sonogashira reaction since 1975. However, this strategy has not received much attention from the organic chemist community until recently. Synergistic Pd/Cu catalysis is becoming a proficient method for the development of catalytic reactions, including several new and efficient cross-coupling reactions. Additionally, several challenging asymmetric reactions, including stereodivergent synthesis, have been discovered by the combined use of a chiral metal catalyst and a second achiral metal catalyst or two chiral metal catalysts. This review provides an overview of this field, with the aims of highlighting both the development of synergistic Pd/Cu catalysis in organic synthesis and the reaction mechanisms involved in this research area.  相似文献   

13.
栗艳丽  袁振东  侯燕 《化学通报》2024,87(2):190-202
手性螺环配体和催化剂已被公认是一类优势手性配体和催化剂。手性螺环配体的相关研究,促进了不对称催化领域的发展。根据螺环骨架类型进行分类,分别讨论具有螺[4.4]壬烷骨架、螺二氢茚骨架、螺[4.4]壬二烯骨架以及螺二色烷骨架的手性螺环双膦配体的合成及在不对称催化反应中的应用,为今后发展新的不对称催化体系提供了重要参考。  相似文献   

14.
糖类化合物价廉易得,具有天然手性结构,糖环上的多个羟基经过修饰,可以连接多种官能团。近年来手性糖类化合物的合成与应用研究引起了人们的广泛关注,尤其是在不对称合成和催化中的应用研究已成为有机化学中非常活跃的领域。碳水化合物含磷手性配体在不对称催化反应中的应用研究进展十分迅速,本文综述了近年来碳水化合物含磷手性配体与金属形成络合物作为催化剂,在不对称催化氢化、不对称烯丙位取代和不对称氢甲酰化等反应中的研究进展。  相似文献   

15.
Chiral Brønsted base catalysis is a fascinating and highly explored field of research. For many years catalysts based on chincona alkaloid chiral scaffolds have constituted privileged systems widely employed in numerous base‐promoted organic transformations. Recently, a novel group of chiral base catalysts has been successfully introduced. The application of organosuperbases, namely cyclopropenimines, guanidines, and iminophosphoranes, as chiral catalysts is receiving increasing attention. The aim of this Concept article is to summarize recent progress in the field of chiral iminophosphorane superbase organocatalysis. Catalysts design, different approaches to their synthesis, and applications in asymmetric synthesis are outlined and discussed in detail.  相似文献   

16.
张占辉 《有机化学》2005,25(4):355-363
手性螺环配体的合成及其在不对称催化反应中的应用是不对称合成和催化研究中重要的研究领域之一, 一些手性螺环配体被合成出来并成功地应用于不对称催化反应中. 综述了近十年来手性螺环配体的合成及在不对称催化反应中的应用研究进展.  相似文献   

17.
Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion‐pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction.  相似文献   

18.
Quaternary ammonium salts play an important role in asymmetric catalysis. In this Minireview, how asymmetric ion-pairing catalysis with ammonium ions has been utilized in organic synthesis is explained, particularly in the design of novel catalytic cycles. This includes the use of chiral ammonium-based catalysts for the construction of challenging stereogenic centers. Ammonium-derived electrophilic reagents, typically formed in situ and in the context of phase-transfer catalysis (PTC), have also been utilized in asymmetric bond-forming reactions. Furthermore, ammonium salts have been employed as substrates in several stereocontrolled C−N bond cleavage processes, leading to enantioenriched products by using novel asymmetric induction modes. In addition, merging ammonium ion-pairing catalysis with other catalytic approaches has also emerged as a new platform for achieving previously less straightforward reactions, thereby allowing new synthetic applications.  相似文献   

19.
Phase‐transfer catalysis has been recognized as a powerful method for establishing practical protocols for organic synthesis, because it offers several advantages, such as operational simplicity, mild reaction conditions, suitability for large‐scale synthesis, and the environmentally benign nature of the reaction system. Since the pioneering studies on highly enantioselective alkylations promoted by chiral phase‐transfer catalysts, this research field has served as an attractive area for the pursuit of “green” sustainable chemistry. A wide variety of asymmetric transformations catalyzed by chiral onium salts and crown ethers have been developed for the synthesis of valuable organic compounds in the past several decades, especially in recent years.  相似文献   

20.
Asymmetric catalysis with transition‐metal complexes is the basis for a vast array of stereoselective transformations and has changed the face of modern synthetic chemistry. Key to this success has been the design of chiral ligands to control the regio‐, diastereo‐, and enantioselectivity. Phosphoramidites have emerged as a highly versatile and readily accessible class of chiral ligands. Their modular structure enables the formation of ligand libraries and easy fine‐tuning for a specific catalytic reaction. Phosphoramidites frequently show exceptional levels of stereocontrol, and their monodentate nature is essential in combinatorial catalysis, where a ligand‐mixture approach is used. In this Review, recent developments in asymmetric catalysis with phosphoramidites used as ligands are discussed, with a focus on the formation of carbon–carbon and carbon–heteroatom bonds.  相似文献   

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