含二茂铁基的多核金属有机配合物的反应化学

本文简要介绍了含二茂铁基的多核多属有机配合物在高选择性有机合成中的应用，较详细地说明了手性二茂铁膦配体与过渡金属可以生成非常有效的不对称合成催化剂。     

Proline-catalysed Mannich reactions of acetaldehyde

Small organic molecules recently emerged as a third class of broadly useful asymmetric catalysts that direct reactions to yield predominantly one chiral product, complementing enzymes and metal complexes. For instance, the amino acid proline and its derivatives are useful for the catalytic activation of carbonyl compounds via nucleophilic enamine intermediates. Several important carbon-carbon bond-forming reactions, including the Mannich reaction, have been developed using this approach, all of which are useful for making chiral, biologically relevant compounds. Remarkably, despite attempts, the simplest of all nucleophiles, acetaldehyde, could not be used in this way. Here we show that acetaldehyde is a powerful nucleophile in asymmetric, proline-catalysed Mannich reactions with N-tert-butoxycarbonyl (N-Boc)-imines, yielding beta-amino aldehydes with extremely high enantioselectivities-desirable products as drug intermediates and in the synthesis of other biologically active molecules. Although acetaldehyde has been used as a nucleophile in reactions with biological catalysts such as aldolases and thiamine-dependent enzymes, and has also been employed indirectly, its use as an inexpensive and versatile two-carbon nucleophile in asymmetric, small-molecule catalysis will find many practical applications.     

（R）—苯基甘氨醇的一些化学有择反应

讨论了（Ｒ）－苯基甘氨醇的一些化学选择性反应，所制得的手性合物在不对称合成中具有应用价值。     

过渡金属/磷配体络合物催化不对称氢甲酰化研究进展

手性醛是合成生物活性物质如药物活性分子等的重要中间体,及各种高附加值精细化学品如香料等的起始原料,潜手性烯烃及其衍生物的不对称氢甲酰化是合成光学活性醛的重要方法之一.在烯烃的不对称氢甲酰化中铑与膦形成的催化体系因活性高、选择性好等优点而被广泛应用.主要介绍了近年来几类新型手性磷配体与铑形成的络合物催化剂在不对称氢甲酰化反应中的应用研究结果,如Rh/手性双-3,4-二氮磷杂环戊烷配体(S,S,S)-Bisdiazaphos和(R,S)-NEt-Yanpho络合物催化剂等.     

Catalytic Asymmetric Carbon-Carbon Forming Reactions Catalyzed Chiral Schiff Base-Metal Complexes

1 Results In 1991, we disclosed the novel asymmetric catalysts prepared from chiral Schiff base and titanium alkoxide in the reaction of asymmetric silylcyanation of aldehydes (eq.1)[1]. Since our first report, chiral Schiff base-metal complex was proven to be efficient in a variety of asymmetric reactions. We reported the first example of enantioselective addition of diketene to aldehydes promoted by chiral Schiff base-titanium alkoxide complexes (eq.2)[2]. The products of this reaction have been cove...     

Recent advances in catalytic asymmetric hydrogenation： Renaissance of the monodentate phosphorus ligands

The history for the development of chiral phosphorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent advances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced a renaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.     

手性稀土配合物在不对称催化应用中的研究进展

近年来随着光学纯化合物需求的不断增大,不对称催化逐渐成为科学研究的前沿领域之一.稀土元素则是由周期表中ⅢB族Sc、Y和镧系元素(La~Lu)的17种元素组成.相比其他过渡金属与各类配体轨道间的作用,稀土金属有其独特之处,因此,近年来手性稀土配合物在不对称催化领域的应用,也逐渐引起人们的重视.根据各类手性配体中所含配位原子的不同,对手性稀土配合物的类型及相关的不对称催化反应作简要综述.     

羧酸衍生物的烯醇盐的立体选择性氧化二聚反应

综述羧酸衍生物的烯醇盐氧化二聚成键的规律，重点是立体选择性的过程。近期进展是利用手性辅助试剂，如各种不同的手性酯和手性酰胺不对称合成立体专一性的1，4-二羰基化合物．为不对称合成琥珀酸衍生物提供了有效方法。     

手性二级胺催化的不对称串联反应研究进展

有机催化的不对称串联反应是快速构建复杂分子的重要的方法之一：利用简单易得的原料,在温和的反应条件下,经过简单的操作,高选择性地构建结构复杂的有机分子。近年来,使用手性二级胺催化的不对称串联反应取得了显著的进展,已经成为有机催化领域的一个研究热点。根据手性二级胺催化剂活化模式的不同,从亚胺～烯胺和烯胺一亚胺两种活化模式,对手性二级胺催化的不对称串联反应进行了综述,介绍了该领域最新研究进展。     

二茂铁膦键连到Merrifield树脂上的负载研究

开展了通过2-二苯膦基二茂铁基-乙基5-羟基-3-氧杂戊醚(膦配体2)中的羟基键连到Merrifield树脂上的负载研究,制备了一种新的树脂负载的二茂铁膦配体(膦配体3).元素分析测定负载的膦配体量为0.53 mmol/g;31P NMR表明负载的膦保持负载前的三价特征而未被氧化;负载的膦可作为支持配体应用于钯催化的S...     

Structural effects on the magnetic hyperthermia properties of iron oxide nanoparticles

Magnetic iron oxide nanoparticles(IONPs) are heavily explored as diagnostic and therapeutic agents due to their low cost, tunable properties, and biocompatibility. In particular, upon excitation with an alternating current(AC) magnetic field, the NPs generate localized heat that can be exploited for therapeutic hyperthermia treatment of diseased cells or pathogenic microbes. In this review, we focus on how structural changes and inter-particle interactions affect the heating efficiency of iron oxide-based magnetic NPs. Moreover, we present an overview of the different approaches to evaluate the heating performance of IONPs and introduce a new theranostic modality based on magnetic imaging guided–hyperthermia.     

Chiral ligand-protected gold nanoclusters: Considering the optical activity from a viewpoint of ligand dissymmetric field

Chirality is a geometric property of a physical, chemical, or biological object, which is not superimposable on its mirror image. Its significant presence has led to a strong demand in the development of chiral drugs, sensors, catalysts, and photofunctional materials. In recent years, chirality of nanoscale organic/inorganic hybrids has received tremendous attention owing to potential applications in chiral nanotechnology. In particular, with the recent progress in the syntheses and characterizations of atomically precise gold nanoclusters protected by achiral thiolates, atomic level origins of their chirality have been unveiled. On the other hand, chirality or optical activity in metal nanoclusters can also be introduced via the surface chiral ligands, which should be universal for the nanosystems. This tutorial review presents some optically-active metal (gold) nanoclusters protected by chiral thiolates or phosphines, and their chiroptical (or circular dichroism; CD) properties are discussed mostly from a viewpoint of the ligand dissymmetric field scheme. The examples are the gold nanoclusters protected by (R)-/(S)-2-phenylpropane-1-thiol, (R)-/(S)-mercaptosuccinic acid, phenylboronate-D/L-fructose complexes, phosphine sulfonate-ephedrinium ion pairs, or glutathione. Some methodologies for versatile asymmetric transformation and chiroptical controls of the nanocluster compounds are also described. In the dissymmetric field model as the origin of optical activity, the chiroptical responses of the gold nanoclusters are strongly associated with coupled oscillator and/or CD stealing mechanisms based on the concept of induced CD (ICD) derived from a perturbation theory, so on this basis, some characteristic features of the observed CD responses of chiral ligand-protected gold nanoclusters are presented in detail. We believe that various kinds of origins of chirality found in ligand-protected gold nanoclusters may provide models for understanding those of many related nanomaterials.     

环磺酰胺手性辅助试剂诱导不对称羟醛缩合反应的研究

以L-苯丙氨基醇为原料合成一种新颖的3-苄基-5-正丁基环磺酰胺手性辅助试剂,将其酰化后应用于不对称羟醛缩合反应,具有很高的化学产率（85％～94％）和syn式非对映选择性（dr：92：8～99：1）．羟醛缩合产物5a解脱后高产率得到近乎光学纯的产物（2S,3S）-3-羟基-2-甲基-3-苯基丙酸6a,同时可定量回收环磺酰胺手性辅助试剂．     

不对称催化氢化反应研究

不对称催化氢化反应具有完美的原子经济性和清洁高效等特点,是最受青睐的不对称合成方法之一。虽然人们已经发展了很多用于不对称催化氢化的催化剂,但是这些催化剂往往存在稳定性差、活性低、底物适用范围窄、反应条件苛刻等问题,真正高效的手性催化剂很少。通过系统深入的研究,发展了30多个用于不对称氢化反应的原创性手性螺环催化剂,实现了潜手性酮、α-取代羰基化合物、不饱和羧酸、非保护烯胺等4大类20多种不对称氢化反应,反应的活性和对映选择性处于目前的最好水平,其中部分反应已经被用于手性药物及其中间体的生产,在国内外产生了重要影响。     

有机小分子催化不对称环氧化

光学活性的环氧化合物是有机合成的重要原料.不对称环氧化反应可以使潜手性的烯烃转化为带有手性碳的环氧化合物,这个反应在医药、农药、香料等合成上具有重要的意义.有机小分子催化烯烃的不对称环氧化是一种高效,绿色的光学活性环氧化合物的合成方法,目前该类反应主要是通过手性酮和手性亚胺盐来催化实现的.文章介绍了该类反应的催化机理,并概述了这两类有机小分子催化的不对称环氧化反应的研究进展.     

Hydroformylation of olefins catalyzed by chiral phosphite-Rh（I） complexes

A series of chiral phosphite ligands based on chiral binaphthol have been designed and synthesized. Their Rhodium(I) complexes were found to be efficient catalysts for the asymmetric hydroformylation of styrene and vinyl acetate and showed excellent catalytic activities and chemos-electivities as well as good regioselectivities (branched alde-hyde/linear aldehyde). The enantioselectivities up to 37.0% ee and 38.1% ee were achieved in the hydroformylation of styrene and vinyl acetate respectively. The chiral bidentate phosphite ligands provided better enantioselectivities, however lower regioselectivities than the chiral mono-dentate phosphite ligand.     

手性β-氨基醇催化的芳香醛对映选择性炔化反应

 手性β-氨基醇是不对称催化反应中应用最为广泛的手性配体之一.以L-苯丙氨酸为原料简捷合成的手性β-氨基醇L^*为手性配体,对不同取代芳香醛的对映选择性炔化反应进行了研究,结果表明其对该反应具有一定的不对称催化活性,光学收率(e.e值)最高达78.9%.     

咪唑环卡宾钯配合物参与的偶联反应新进展

钯催化交叉偶联反应可高效构建碳-碳键、碳-杂键等复杂结构单元,应用十分广泛。除了传统的膦配体催化体系外,新兴的氮杂环卡宾催化体系已在多种偶联反应中得到成功的应用。目前针对该催化体系的研究主要集中于新氮杂环卡宾配体结构的构建、新辅助配体的配合使用以及新反应体系的开发等。氮杂环卡宾参与的偶联反应也越来越向着绿色、可持续的方向发展。结合最新的文献报道,针对咪唑环类氮杂环卡宾配合物在上述方向的发展进行详细评述。     

PEG支载手性二胺催化不对称多米诺迈克尔-羟醛缩合反应

以天然L-酪氨酸为手性原料,通过酚羟基将其支载在聚乙二醇上,经过系列支载化反应得到聚乙二醇支载可溶的双（S）-3-（4-氧苯基）-N1-甲基丙烷-1,2-二胺手性催化剂,以水为溶剂,25℃下催化β-酮酯与α,β-不饱和酮的不对称多米诺迈克尔-羟醛缩合反应,得到环己酮,具有良好的不对称催化效果,产物分离纯化方便,手性催化剂可回收并重复使用4次后,不对称催化效果没有明显变化.     

含氮手性离子液体的合成及应用研究进展

综述咪唑鎓盐、季铵盐和吡啶鎓盐等含氮手性离子液体的合成及其在不对称催化反应中的应用研究进展.研究成果表明,手性离子液体的制备既可以直接使用手性源(如氨基酸、氨基醇、或生物碱等),也可以利用不对称合成.含氮手性离子液体手性中心的构建、固载化方法以及构效关系将是今后研究工作的重点.