糖基配体促进的铜催化水相Ullmann型C—N偶联反应

开发了一种用于实现水相中的铜催化Ullmann型C—N偶联反应的绿色且高效的催化体系.以Cu I为催化剂、N-(2-羟乙基)-β-D-吡喃葡萄糖胺为配体,芳基碘化物、芳基溴化物与N-亲核试剂都能在水中实现偶联反应,芳基碘化物的吸电子取代和供电子取代效应影响较小.偶联产物的收率良好(61%~96%).该催化体系也成功扩展到各种吲哚与4-碘苯甲醚的水相偶联反应中.绿色且可降解的配体、温和的反应条件、绿色的水溶剂和广泛的底物适用性,使得该水相偶联策略具有重要的意义.     

芳基乙烯基硅烷与芳基卤代物的Hiyama偶联反应（英文）

Hiyama偶联反应已经发展成为一种构筑C—C键的常用方法,尤其是在芳基-芳基和芳基-烯基偶联反应领域.Hiyama偶联反应通常需要使用R—SiF₃、R—Si(OMe)₃等活性高但稳定性差的有机硅试剂,发展基于稳定硅烷的Hiyama偶联反应是该领域重要的研究方向.报道了一类钯催化芳基乙烯基硅烷和芳基卤代物的交叉偶联反应,利用芳基乙烯基硅烷实现芳基化反应.反应具有较好的官能团兼容性,为制备二芳基类化合物提供了一种简便高效的途径.     

芳基-芳基偶联反应的研究进展

综述了近年来芳基-芳基偶联反应的研究进展, 包括不同类型芳基-芳基偶联反应的特点、机理和应用, 尤其是对立体选择性和区域选择性的偶联方法进行了重点介绍.     

α-芳基烯基膦酸酯的合成研究进展

α-芳基烯基膦酸酯是一类重要的有机磷化合物,并且是合成其它有机磷分子的重要中间体.重点综述了过渡金属催化合成α-芳基烯基膦酸酯的进展,如磷氢化反应、C—C偶联反应和C—P偶联反应等,其它非金属催化条件下的几类合成方法也进行了概述.对α-芳基烯基膦酸酯的有机转化及在膦胺霉素衍生物合成中的应用也进行了探讨.     

铜催化二氟乙醇的芳基醚化反应及其机理研究（英文）

有机氟硅化合物是元素有机化学中最重要的高端产品种类之一,极具研究价值.开发了含二氟乙醇农药的新工艺技术,发展了一种条件温和和高效的铜催化二氟乙醇芳基醚化反应,通过大量的配体筛选和条件优化,建立了二氟乙醇和芳基溴或芳基碘的C—O偶联反应,简易合成出各种芳基取代的二氟乙基芳基醚.该反应以CuI为催化剂,在8-羟基喹啉和叔丁醇钾存在下顺利进行,具有广泛的底物适用性.ESI-MS分析证明,该催化过程可能存在三价铜催化机制,密度泛函理论(DFT)计算进一步表明该反应机理可能涉及三价铜的氧化加成、亲核取代及还原消除过程.     

过渡金属催化的不对称芳基-芳基偶联反应：轴手性联芳基化合物的合成研究进展

轴手性联芳基化合物广泛应用于材料、染料、医药、不对称催化等诸多领域,是一类重要的化合物。过渡金属催化的不对称偶联反应作为经典的合成方法一直是合成化学家关注的对象。本文介绍了过渡金属催化的芳基-芳基偶联反应在轴手性联芳类化合物的立体选择性合成方面的进展。      

芳基单取代炔合成方法

综述了各种芳基单取代炔的制备方法;分析了各种方法的反应机制和特点,认为钯催化偶联-消去反应合成芳基单取代炔是比较好的方法。芳基取代聚炔及其衍生物呈现出光、电、磁等许多新颖的性能。芳基单取代炔的合成对芳基取代聚炔的制备起到关键作用。参考文献69篇。     

无碱参与的铜催化芳基硼酸和硫酚的偶联反应研究

无碱参与的条件下,研究了Cu盐催化芳基硼酸与硫酚的偶联反应.通过反应溶剂、温度、铜盐、配体等条件的优化,结果表明在空气中,以1,10-菲啰啉-醋酸铜为催化剂,DMSO/H2O(V∶V=1∶1)作为溶剂,反应温度为60℃,以较高产率合成二芳基硫醚.     

银催化炔丙醇与芳基异腈交叉偶联反应:原子经济性合成N-芳基-2,3-联烯酰胺

炔丙醇和芳基异氰在银催化条件下能够发生交叉偶联反应,高产率地生成N-芳基-2,3-联烯酰胺.该反应具有条件温和、原子经济性和底物范围宽泛等优点,多种芳基异腈和炔丙醇均能发生交叉偶联反应,并生成相应的N-芳基-2,3-联烯酰胺.该方法解决了前期工作中异腈种类受限的问题,为合成N-芳基联烯酰胺提供了简便新途径.     

新型含咔唑双膦配体-钯催化 Suzuki 反应

 以 3-溴苯甲醚为原料合成了新型双膦配体 6,6′-二甲氧基-2,2′-二 (二-N-咔唑基膦)-1,1′联苯, 并将该配体与钯组成的配合物用于对溴苯甲醚和苯硼酸的 Suzuki 偶联反应, 考察了溶剂、碱、底物/催化剂摩尔比、膦/钯摩尔比对偶联反应的影响. 结果表明, 该催化体系在 1,4-二氧六环中催化对溴苯甲醚和苯硼酸的 Suzuki 偶联反应得到 99% 的分离产率. 同时, 该催化体系用于其它芳基溴和苯硼酸的 Suzuki 偶联反应也表现出很好的催化性能, 即使芳基溴有较大的空间位阻或具有取代基也能获得很好的结果.     

C1 and C2-symmetric carbohydrate phosphorus ligands in asymmetric catalysis

Carbohydrates are increasingly used as starting materials for the synthesis of enantiopure ligands. They contain a considerable number of stereocenters, and compounds with all possible configurational combinations are readily available. This tutorial review focuses on ligands obtained by the introduction of phosphorus functionalities (mainly phosphinite, phosphite or phosphine) into a carbohydrate framework. They are classified according to their structural features. In this review, ligands are organised as C1 ligands with a pyranoside or furanoside structure, and C2 ligands. Particular attention is paid to water soluble ligands prepared from carbohydrates. General methods for the preparation of the ligands are presented in order to show how the backbones can be obtained from simple carbohydrates. The catalytic results obtained in commonly studied processes are presented in tables in order to facilitate the comparison between the ligands. The advantages and limitations of the use of ligands based on carbohydrates are discussed.     

Ligand displacement reactions of dimer and trimer pyridyl ligand/transition metal complexes

Ligand exchange reactions of pyridyl ligand/transition metal complexes are examined in a quadrupole ion trap mass spectrometer to evaluate the ability of multidentate ligands to displace other pyridyl ligands in complexes where the charge is highly delocalized and there is a great degree of ligand repulsions. Partially or fully coordinated transition metal ions in dimer or trimer species involving small mono- or bidentate pyridyl ligands undergo ligand displacement reactions with larger bi- and tridentate pyridyl ligands. Larger ligands with greater chelation abilities, such as 1,10-phenanthroline and 2,2′:6,2″-terpyridine, are often able to simultaneously displace two nonchelating ligands from a partially coordinated metal ion. However, the analogous reactions involving displacement of bidentate chelating ligands from more fully coordinated transition metal ion complexes are nearly quenched. In other cases, mixed-ligand dimer and trimer complexes are observed, indicating step-wise displacement of the initially complexed ligands.     

Interplay and Competition Between Two Different Types of Redox-Active Ligands in Cobalt Complexes: How to Allocate the Electrons?

The field of molecular transition metal complexes with redox-active ligands is dominated by compounds with one or two units of the same redox-active ligand; complexes in which different redox-active ligands are bound to the same metal are uncommon. This work reports the first molecular coordination compounds in which redox-active bisguanidine or urea azine (biguanidine) ligands as well as oxolene ligands are bound to the same cobalt atom. The combination of two different redox-active ligands leads to mono- as well as unprecedented dinuclear cobalt complexes, being multiple (four or six) center redox systems with intriguing electronic structures, all exhibiting radical ligands. By changing the redox potential of the ligands through derivatisation, the electronic structure of the complexes could be altered in a rational way.     

超分子双膦配体的构筑及应用研究进展

超分子双膦配体是一类新兴起的基于非共价键作用构筑的双膦配体,近年来引起人们的重视.与传统的共价键连接的双膦配体相比,利用非共价相互作用的可逆性和选择性,超分子双膦配体具有合成简便,组合灵活,易于合成超分子配体库,并利用组合化学的方法对催化体系进行优化和筛选等优点.详细综述了近几年发展的基于氢键、配位键、主客体作用和静电作用等弱相互作用的超分子双膦配体,重点讨论了它们的构建方法以及在不对称催化反应中的应用,并对其发展前景进行了展望.     

Complexes of phosphorus halides with two or more coordination bonds

The review considers complexes of phosphorus as central atom with the variously dentate ligands of different topology and type of donor groups. The most stable complexes form the N-donor ligands, which are strong nucleophiles. The P-donor ligands stabilize the lower oxidation state of phosphorus. Only a few examples of complexes is known of the neutral O- and S-donor ligands. The most stable are the chelates with the ligands forming with the phosphorus atom alongside a donor-acceptor bond also a common covalent bond.     

轴不稳定手性配体的开发及其在不对称催化反应中的应用

轴不稳定配体应用于不对称催化有其独到的特点, 不同于传统的轴稳定手性配体. 综述了轴不稳定的噁唑啉、双膦、单膦、双羟基及N—O等配体的开发及其在不对称催化中的应用.     

The Search for Enhanced σ-Donor Ligands to Stabilize Boron-Boron Multiple Bonds

Boron-boron multiple bonds, such as those found in diborenes and diborynes, are typically stabilized by σ-donor ligands that furnish electron density to these otherwise electron-deficient species. These compounds are not only of fundamental importance in the study of chemical bonding, but can also activate small molecules in a chemistry reminiscent of that carried out by transition metals. In the pursuit of designing new and improved σ-donor ligands to stabilize diborenes and diborynes suitable to activate small molecules, we performed density functional calculations to evaluate the Lewis basicity of a series of σ-donor ligands. For this evaluation, we analysed the interaction between the boranes and the σ-donor ligands in model systems L→BX₃ (X=F and Me) using energy decomposition analyses. We found that electronic bond energies of the L→BX₃ adducts correlate well with the ionization energies of the ligands and that ligands with high or medium basicity stabilize diborynes better than ligands with low basicity. We also learnt that beryllium-based ligands are promising since they are able to stabilize L→B≡B←L diborynes without significantly reducing the triple bond character of the B≡B bond.     

不对称催化氢甲酰化中高效手性配体的进展*

比较系统地总结了应用于不对称催化氢甲酰化方面各类配体的合成、设计思路及性能,侧重于评述高效配体的最新进展.     

Kinetics study of the binding of multivalent ligands on size-selected gold nanoparticles

The effect of ligand multivalency and nanoparticle size on the binding kinetics of thiol ligands on gold nanoparticles is investigated by exchanging monovalently bound pyrene on gold nanoparticles against flexible mono- and multivalent thiol ligands. Variable-sized gold nanoparticles of 2.2 ± 0.4, 3.2 ± 0.7, and 4.4 ± 0.9 nm diameter are used as substrates. The particles are coated by thiol functionalized pyrene ligands and the binding kinetics of the thiol ligands is studied by time-resolved fluorescence spectroscopy. The effect of multivalency on the binding kinetics is evaluated by comparing the rate constants of ligands of different valency. This comparison reveals that the multivalent ligands are exchanging substantially more rapidly than the monovalent ones. A particle size dependence of the rate constants is also observed, which is used to derive structural information on the binding of the mono- and multivalent ligands to the nanoparticle surface.     

Metal-chelating 1,3-bis(2′-pyridylimino)isoindolines

A variety of novel chelating 1,3-bis(2′-pyridylimino)isoindoline ligands were prepared and characterized including ligands substituted on both the pyridyl and isoindoline ring systems. Noteworthy are the first iso-indoline ligands with solubility in aqueous media. A convenient preparation of 4-alkoxyphthalonitriles is reported; these compounds are readily obtained from 4-nitrophthalonitrile and are suitable starting materials for alkoxy-substituted ligands.