新型手性环状胺膦配体的设计合成及在酮的不对称还原中的应用

新型手性配体的设计合成是不对称催化研究的重要内容,其中手性胺膦配体因同时含有"软"的磷原子和"硬"的氮原子而具有丰富的配位化学性能和优秀的不对称诱导能力.本文总结了本研究组最近设计合成的手性环状胺膦配体的制备、表征及其在铁催化酮的不对称还原中的应用.手性1,2-环己二胺与双(2-甲酰基苯基)苯基膦通过[2+2]环缩合反应能够顺利获得手性22元环的亚胺膦配体21,该配体经Na BH4还原后生成大环胺膦配体22.利用手性大环胺膦配体22与Fe3(CO)12原位生成的催化体系,能够高活性、高对映选择性地实现包括杂环芳香酮在内50多种酮的不对称转移氢化和不对称氢化反应,其S/C(底物与催化剂的摩尔比)最高可达5000:1,产物手性芳香醇的光学纯度高达99%ee.     

P-手性膦配体促进的手性药物高效合成

发展高效实用的不对称催化反应对手性药物的简洁合成具有重要的意义,而手性配体和催化剂对于发展高效的不对称催化反应尤为关键.综述了基于苯并氧杂膦烷结构的P-手性单膦和双膦配体的设计理念以及它们在手性药物合成中的应用.这类配体具有P-手性、刚性,大位阻和富电子等结构特征,物理化学性质稳定,并且易于衍生化,在过渡金属催化的不对称氢化、偶联、环化和加成反应中表现出优异的催化性能.这些不对称催化反应的发展促进了一系列重要药物分子的高效不对称合成.     

新型手性膦配体的合成及其在不对称催化中应用的新进展

光学活性的膦配体在过渡金属催化的不对称合成中起着非常重要的作用 .到目前为止 ,已相继出现 2 0 0 0多个新手性膦配体 .经多年的大量研究积累 ,以 BINAP为代表的几个手性膦配体已用于生产有用的光学活性物质 ,工业上应用的成功极大地推动了手性膦化学的基础研究 .目前 ,对新型的不对称催化反应的探索以及新的手性膦配体的设计合成研究非常活跃[1] .我们重点介绍 1 990年以后报导的手性膦配体的合成及其在不对称催化反应方面的应用 .1新的手性双膦配体具有 C2 轴对称性的双齿膦配体 ,以其优良的结构特征一直受到人们的青睐 ,大量的具有 …     

钯-单膦催化剂在烯烃不对称硅氢化反应中的应用

烯烃的不对称硅氢化反应作为合成手性仲醇的一种重要方法,受到了国内外众多学者的关注.研究表明,钯-单膦催化剂对该类反应有着优异的催化活性和选择性.由于结构稳定、易于合成及修饰、催化性能独特等优点,手性单膦配体取得了迅速的发展.其中,基于二茂铁骨架的平面手性膦配体、基于联芳基骨架的轴手性膦配体以及手性亚磷酰胺酯配体在烯烃的不对称硅氢化反应中取得了优异的催化效果.详细总结了近年来钯-单膦催化剂催化的烷基烯烃、苯乙烯及其衍生物、1,3-二烯烃等底物的不对称硅氢化反应研究进展,并对其发展前景进行了展望.     

过渡金属/磷配体催化不对称氢化反应研究进展

正手性过渡金属配合物催化的不对称氢化是合成手性药物、农药和精细化工中间体的重要方法.到目前为止,已经有一些过渡金属/配体配合物催化的不对称氢化反应得到工业化应用,典型的实例如孟山都公司采用手性双齿膦配体DIPAMP生产L     

手性膦配体的合成及其在不对称催化反应中的应用研究进展

手性膦配体的合成及其在不对称催化反应中的应用一直是不对称有机合成和催 化研究中非常重要的研究领域，大量的单齿、双齿和多齿磷配体被合成出来并成功 地应用于不对称催化研究。综述了近十几年来手性磷配体的研究进展。     

新型手性胺膦-铱体系催化芳香酮的不对称转移氢化

合成了含-CH_3取代基的PNNP型手性双胺双膦配体, 并采用核磁共振、质谱、红外光谱及圆二色光谱等方法对其进行了表征. 在异丙醇溶液中, 考察了该配体与[IrHCI_2(COD)]_2组成的手性胺膦-铱体系对多种芳香酮的不对称转移氢化性能. 结果表明, 该手性胺膦-铱体系是催化多种芳香酮不对称氢转移氢化的优秀催化剂. 在室温下, 用该体系催化1,1-二苯基丙酮时, 可得到99%的转化率和99% ee的对映选择性.     

手性二茂金属膦配体在不对称合成中的应用及新进展

手性二茂金属膦配体在不对称合成中的应用及新进展牟宗刚，吕士杰，周宏英，傅宏祥（中国科学院兰州化学物理研究所兰州７３００００）关键词二茂铁膦配体，烯丙基化合物，二茂钌膦配体，不对称合成，不对称催化，均相催化１前言众所周知，催化作用的研究已成为近代化学的...     

不对称催化氢化制备（S）—（＋）—萘普生：Ⅰ.不对称催化剂的合成及催化性能

全过程合成出手性双膦配体２，２’－双（二苯基膦）－６，６’－二甲基联苯，以金属钌为中心原子，制备出几种不对称催化剂。通过考察不对称氢化制备（Ｓ）－（＋）－萘普生的反应光学收率，研究了催化剂的催化性能，并与联萘型双膦配体催化剂进行了比较。     

铑催化的烯烃不对称氢甲酰化反应研究进展

烯烃的氢甲酰化反应是工业上最重要的均相催化反应之一,而通过烯烃的不对称氢甲酰化反应合成光学活性醛,对于药物、农药、香料和天然产物合成方面具有重要的意义.近年来,由于铑与膦配体形成的络合物在催化烯烃的不对称氢甲酰化反应中具有反应活性高、选择性好等优点而引起广泛关注.通过调控铑络合物中手性膦配体的电子与立体化学环境,已经成为实现不对称氢甲酰化反应高活性和高选择性最主要的方法.主要介绍了近期在铑催化的不对称氢甲酰化反应研究方面取得的进展,重点介绍几类代表性的手性膦配体在此类反应中的应用.     

Recent Advances in the Development of Chiral Gold Complexes for Catalytic Asymmetric Catalysis

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.     

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.     

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.     

Homogeneous Oligomeric Ligands Prepared via Radical Polymerization that Recognize and Neutralize a Target Peptide

Abiotic ligands that bind to specific biomolecules have attracted attention as substitutes for biomolecular ligands, such as antibodies and aptamers. Radical polymerization enables the production of robust polymeric ligands from inexpensive functional monomers. However, little has been reported about the production of monodispersed polymeric ligands. Herein, we present homogeneous ligands prepared via radical polymerization that recognize epitope sequences on a target peptide and neutralize the toxicity of the peptide. Taking advantage of controlled radical polymerization and separation, a library of multifunctional oligomers with discrete numbers of functional groups was prepared. Affinity screening revealed that the sequence specificity of the oligomer ligands strongly depended on the number of functional groups. The process reported here will become a general step for the development of abiotic ligands that recognize specific peptide sequences.     

Iridium-Catalyzed Domino Hydroformylation/Hydrogenation of Olefins to Alcohols: Synergy of Two Ligands

A novel one-pot iridium-catalyzed domino hydroxymethylation of olefins, which relies on using two different ligands at the same time, is reported. DFT computation reveals different activities for the individual hydroformylation and hydrogenation steps in the presence of mono- and bidentate ligands. Whereas bidentate ligands have higher hydrogenation activity, monodentate ligands show higher hydroformylation activity. Accordingly, a catalyst system is introduced that uses dual ligands in the whole domino process. Control experiments show that the overall selectivity is kinetically controlled. Both computation and experiment explain the function of the two optimized ligands during the domino process.     

Novel benzoferrocenyl chiral ligands: Synthesis and evaluation of their suitability for asymmetric catalysis

Four benzoferrocenyl phosphorus chiral ligands were conveniently prepared in good overall yields. These ligands were found to be stable in solid form and in solution. Two of the four ligands were resolved by chiral HPLC. Unlike a reported bis(phosphino-η⁵-indenyl)iron(II) complex, in which the indenyl ligands undergo ring flipping through an η¹-intermediate, these two ligands were found to be configurationally stable in solution and in solid state. The suitability of these ligands for enantioselective catalysis was assessed in studies on allylic alkylation reactions. When the two less sterically hindered ligands were used, excellent chemical yields were obtained, but the other two more sterically hindered ones gave lower yields. When the two enantiopure ligands were used, enantioselectivity of up to 51% ee was observed. These findings suggest that benzoferrocene derivatives may be used as chiral ligands for asymmetric catalysis.     

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.     

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.     

Tertiary-poly-amine ligands as stabilisers of transition metal complexes with uncommon oxidation states

Abstract

Tertiary-amine ligands are known to be poorer [sgrave] donor ligands than the corresponding primary- or secondary-amine ligands. They are known to shift the redox potentials of given couples to the anodic direction relative to the corresponding complexes with primary- or secondary-amine ligands. A review of data in the literature and of recent results on nickel complexes with tetra-aza-macrocyclic ligands and copper complexes with open chain polyamine ligands suggests that the major source for these effects is the poorer solvation of the complexes with the tertiary-amine complexes due to the lack of hydrogen bonding between the complexes and the solvent, or the counter ions. Thus the stabilisation of low valent transition metal complexes by tertiary-amine ligands is due to thermodynamic reasons. On the other hand, tertiary-amine-macrocyclic ligands stabilise high valent complexes because the route to the formation of imine groups is kinetically inhibited in these complexes.     

Synthesis and photoluminescence properties of BF2 complexes with 1,3-diketone ligands

BF₂ complexes with 1,3-diketone ligands were synthesized, and their optical and electrochemical properties were studied. The colors of the complexes varied depending on the structures of the 1,3-diketone ligands. The absorption and emission maxima of the complexes with 1,3-diaryl-1,3-diketone ligands were considerably red shifted as compared to those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands, suggesting an extended π-conjugation of the 1,3-diaryl-1,3-diketone moieties. The molar absorption coefficients and quantum yields of the complexes with 1,3-diaryl-1,3-diketone ligands were larger than those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands. Cyclic voltammetry measurements revealed that the reduction potentials of the BF₂ complexes were higher than those of the free ligands. These complexes exhibited various emission colors in the solid states due to the intermolecular interactions.