手性胺醇稀土配合物的合成、荧光性质及其催化芳香酮的不对称氢化反应

合成了三种新的含C₂-对称轴的手性胺醇(PhOHCHCH₂)₂NCH₂C₆H₄R (R＝OCH₃, L₁; R＝CH₃, L₂; R＝Cl, L₃), 将其与无水氯化稀土LnCl₃•4THF (Ln＝La, Sm, Gd)反应生成了九个新的胺醇类稀土配合物LLnCl•2THF (L＝L₁, L₂, L₃; Ln＝La, Sm, Gd). 用元素分析、热重分析、红外和紫外光谱等手段对它们进行了表征. 荧光光谱显示一些配合物具有荧光性能. 原位催化芳香酮的不对称氢化反应表明: L₁/SmCl₃•4THF体系催化苯乙酮不对称氢化反应的转化率达71%, 相应的对映体过量值达32%.     

Synthesis and Characterization of the Chiral Skeleton Cluster [NiRuMo(CO)_5(μ_3-S)(η~5-C_5H_5)(η~5-C_5H_4COCH_3)]

1 INTRODUCTION The chemistry of transition metal cluster has enjoyed an exceptional growth since the mid 1970s[1, 2], especially in recent years the structural and bonding aspects of mixed-metal tetrahedral skeleton clusters have been extensively studied[3]. One important reason is that such chiral cluster can induce an asymmetric catalysis potentially. In our research group, considerable efforts have been directed to the synthesis of chiral tetrahedral clusters containing four different…     

Derivatization of carboxylic acids with 9-bromomethylacridine using micellar phase-transfer catalysis

Summary Micellar phase-transfer catalysis (MPTC) offers the opportunity to derivatize carboxylic acids directly in an aqueous matrix without prior extraction of the acids into a suitable aprotic solvent. The currently developed MPTC system consists of a non-ionic surfactant, Arkopal N-130, an ion-pair agent, tetrakis-(decyl)-ammonium bromide, and a novel fluorescence reagent, 9-bromomethylacridine. The MPTC system can be applied to the derivatization of many types of carboxylic acids. The reaction rate is affected by the lipophilicity of the acid and by the presence of other functional groups. For lipophilic carboxylic acids the reaction is complete within 5 min at 60°C and pH 7.0.     

一种新型可溶性高聚物负载手性配体的合成及其催化烯烃的不对称双羟化反应研究

在碱性条件下, 聚乙二醇单甲醚(HO\|OPEG\|OMe)与1,4-二氟蒽醌进行亲核单取代反应生成中间体F\|AQN-OPEG-OMe, 产率88%. F-AQN-OPEG-OMe与奎宁锂进行亲核取代反应, 以95.6%的产率得到新型手性配体QN\|AQN\|OPEG-Me. QN-QN\|OPEG-Me与OsO4原位配位生成的均相催化剂在4种烯烃的不对称双羟化反应中表现出较高的对映选择性(92%~99%e.e.)和化学产率(80%~94%). 催化活性和立体选择性与Sharpless手性配体(DHQ)2AQN相当. 反应结束后, 配体可用乙醚沉淀回收, 循环使用5次, 催化剂的催化活性和立体选择性无明显改变, 配体的回收率均在95%~97%之间.     

Second‐harmonic response of a series of chiral polyesters: A joint experimental and theoretical study

A series of polyesters with π‐conjugated donor–acceptor segments was synthesized by the condensation of azobenzene‐4,4′‐dicarbonylchloride with 1,4:3,6‐dianhydro‐D‐sorbitol ([α] = + 42.5°) and biphenolic chromophores, bis(4‐hydroxyphenylazo)‐2,2′‐dinitrodiphenylmethane and bis(4‐hydroxyphenylazo)‐2,2′‐dinitrodiphenylsulfone. The polymers were characterized by spectral methods (IR, ultraviolet–visible, and NMR), thermal methods (thermogravimetry and differential scanning calorimetry), wide‐angle X‐ray scattering, and polarimetry. The polymers containing isosorbide units were optically active and crystalline. They exhibited glass‐transition temperature values between 100 and 160 °C and were stable up to 400 °C. The second‐harmonic generation (SHG) efficiency of the polymers was experimentally verified by a powder‐reflection technique with 2‐methyl‐4‐nitroaniline as a reference. The SHG efficiencies of the polymers were compared to those of the chromophores and explained as a function of the percentage of chiral composition. The hyperpolarizability β values were also determined by a two‐level model solvatochromic method and computational methods. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2868–2877, 2002     

Total spontaneous resolution of chiral covalent networks from stereochemically labile metal complexes

Stereochemically labile copper and zinc complexes with the N,N'-dimethylethylenediamine ligand (dmeda) have been shown to be promising precursors for the total spontaneous resolution of chiral covalent networks. (N,N')-[Cu(NO3)2(dmeda)]infinity crystallises as a conglomerate and yields either enantiopure (R,R)-1 or enantiopure (S,S)-1. A mixed-valence copper(I/II) complex, [{Cu(II)Br2(dmeda)}3(Cu(I)Br)2]infinity (2), which crystallises as a pair of interpenetrating chiral (10,3)-a nets, is formed from CuBr, CuBr2 and dmeda. One net contains ligands with solely (R,R) configuration and exhibits helices with (P) configuration while the other has solely (S,S)-dmeda ligands and gives rise to a net in which the helices have (M) configuration. The whole crystalline arrangement is racemic, because the interpenetrating chiral nets are of opposite handedness. With zinc chloride (R,S)-[ZnCl(dmeda)2]2[ZnCl4] (3) is obtained, which is a network structure, although not chiral. Total spontaneous resolution of stereochemically labile metal complexes formed from achiral or racemic building blocks is suggested as a viable route for the preparation of covalent chiral networks. Once the absolute structure of the compound has been determined by X-ray crystallography, a quantitative determination of the enantiomeric excess of the bulk product can be undertaken by means of solid-state CD spectroscopy.     

高效液相色谱蛋白质手性固定相

本文综述了近年文献中已报道的各种高效液相色谱蛋白质（酶）手性固定相及其在手性拆分中的应用，并阐述了蛋白质作为手性选择剂拆分机理的研究进展。     

手性铜催化剂的制备及在环丙烷羧酯酯不对称合成中的应用

３类手性配体ｄ－１０－樟脑磺酸及其衍生物，α－（－）－羟蒎酮及其衍生物，又恶唑啉６衍生物分别与铜（Ⅱ）形成手性铜配合物，催化重氮乙酸酯与１，１－二苯乙烯或异丁烯的环丙烷化加成反应，得到光学活性环丙羧酸酯，不对称诱导最高可达９５％ｅ．ｅ．。     

Stereoselective routes to substituted β-amino carbonyl compounds via heterodiene [4π+2π] cycloadditions of auxiliary-based C2 symmetric ketene acetals

Heterodiene [4π+2π] cycloadditions of (S,S)-4,5-diaryl-2-methylene-1,3-dioxolanes 1 to a series of β-amido-α,β-unsaturated carbonyl compounds are diastereoselective (d.r.≥4:1). The products can be purified by trituration or crystallisation and hydrolysed with acid to generate the corresponding β-amido carbonyl compounds, the overall sequence effecting an auxiliary-based enantioselective conjugate addition of an acetate enolate, leading to β-aminoacid derivatives.     

利用差异衍生同步分析醛糖和酮糖

建立了一种可同时对醛、酮糖进行精确定性和定量分析的方法。以肌醇作为内标，用80％乙醇超声提取，利用醋酸酐和HMDS＋TMCS（1：3）进行差异衍生，在EI源下用SIM模式进行GC／MS分析。结果表明：11种标准单糖在1—4mg／L范围内线性良好；仪器检出限：醛糖在8．15—22．4μg／L之间；酮糖为2．32μg／L和3．47μg/L；高、中、低3个量的平均回收率在73．0％-95．7％，相对标准偏差在3．1％-10．0％。对枸杞游离单糖进行测定，各单糖含量分别在0．26—368．6mg／g。该方法弥补了以前单糖分析中的缺陷，对既含有醛糖又含有酮糖的样品可同时进行精确的定性定量分析。