茂钛全氟丁基磺酸盐/锌粉体系高效催化不对称单硒醚合成

在室温条件,氮气氛围下,以商用四氢呋喃(THF)为溶剂,10 mol%的茂钛全氟丁基磺酸盐(1·H_2O·THF)/锌粉(1.2equiv.)体系催化二芳基二硒醚与溴代烷反应,高产率地合成了一系列不对称的单硒醚化合物.其可能机理为,锌粉还原Cp_2Ti~Ⅳ(OPf)_2 (Pf=SO_2C_4F_9)生成三价钛配合物Cp_2Ti~ⅢOPf,然后Cp_2Ti~ⅢOPf与ArSeSeAr反应形成中间体Cp_2Ti~ⅣSeAr(OPf),随后与溴代烷反应生成不对称单硒醚化合物.首次报道1·H_2OTHF/Zn体系催化合成不对称单硒醚,该方法具有反应条件温和,操作简单,反应收率高等优点.     

硒插入C-Zn键及其生成物与环氧

硒插入芳基锌的C-Zn键产生对应的芳基硒化锌，它与环氧或α，β-不饱和酯 （腈）在温和的条件下反应生成对应的不对称的硒醚。     

二碘化钐促进的β-羟基不对称硒(碲)醚的合成

二芳基二硒(碲)醚在SmI2作用下, Se-Se(Te-Te)键还原断裂生成的硒(碲)负离子与环氧化物反应, 得到β-羟基不对称硒(碲)醚。     

硒氢化钠亲核加成高收率合成对称硒醚

报道了一种制备对称有机硒醚的新方法:在氮气保护下,以水做溶剂,室温下利用硼氢化钠还原硒粉得到硒氢化钠,与水溶的丙烯酸乙酯发生亲核加成反应,对于水不溶的苯乙炔或其他α,β-不饱和化合物需另加入DMF作溶剂进行反应,共合成了7个对称硒醚产物,其中6个化合物尚未见文献报道,位阻较大的甲基丙烯酸甲酯,可以得到52％的分离收率,其他产物分离收率高达82～94％.     

手性双官能硫族化合物催化烯烃的不对称亲电硫化反应

手性含硫化合物在药物化学和不对称合成领域中应用广泛,发展这类化合物的新合成方法是有机合成化学的重要任务.烯烃的不对称亲电硫化反应为手性含硫化合物的合成提供了一条方便的途径,通过这种方式不仅可以在烯烃母体分子上引入一个含硫基团,同时也能够引入另外一个重要的官能团.我们课题组设计、合成了一系列手性双官能硒醚/硫醚催化剂,并...     

β-榄香烯烃基硒醚的一锅法合成

常温下将硒用N2H4•H2O还原后与卤代烃反应得到对称二硒醚, 不经分离直接用NaBH4还原, 再与13-氯-β-榄香烯作用得到β-榄香烯烃基硒醚. 此一锅法操作简便、条件温和、反应快速而且产率较高, 是合成不对称硒醚的一种简便实用的方法. 对化合物g的初步生物活性实验表明其具有显著的抗氧化作用.     

硒插入C-Zn键及其生成物与环氧、α,β-不饱和酯(腈)的反应

硒插入芳基锌的C-Zn键产生对应的芳基硒化锌,它与环氧或α,β-不饱和酯(腈)在温和的条件反应生成对应的不对称的硒醚.     

合成烯丙基芳基硒醚的一种简便方法——烯丙基锌与二芳基二硒醚反应

烯丙基溴与锌粉在0～10 ℃下THF中反应生成烯丙基锌，后者与二芳基二硒醚 在THF中、室温下反应生成烯丙基芳基硒醚，产率63%～75%。     

α, α'-二胺基二苄基硒醚的合成

本文以苯骈三氮唑、胺和苯甲基醛为原料,发现Mannich反应,生成胺烷基化的苯骈三氮唑衍生物。在此衍生物中,苯骈三氮唑基是亲核取代反应的良好离去基团,易被强亲核试剂的硒负离子取代,生成对称α,α'-二胺基二苄基硒醚。反应易进行,产率较高,产物均为固体,易提纯。这是合成含氮原子的对称硒醚的较好方法。     

铟促进的烯丙基硒醚的合成

烯丙基溴和炔丙基溴在铟促进下与二硒化合物反应，生成烯丙基和炔丙基硒醚。反应无需严格的无水无氧条件，烯丙基溴以α-位与二硒化合物反应，产率55%～91%。     

Differential Pulse Polarography of the Cadmium(II)-Imidazole Complex System

Abstract

A differential pulse polarographic study of the complexation of cadmium(II) with imidazole gives the relationship, Ej/₂ = -0.798 – 0.132 log [imidazole]_t for the cadmium(II) half wave potential (E]/₂) with imidazole concentration. Also, the differences between the half-wave potentials (ΔEj/₂) of the complex and metal ion have been used to determine log g_n (6.75) and coordination number (4) for the cadmium-imidazole complex according to Subrahmanya's method.     

在CdS水悬浮液中O2光吸收的pH效应

为了深入了解间接光腐蚀过程, Grätzel等人曾考察过O₂在CdS和Rh₂0₃/CdS 悬浮液(pH=9)中光吸收行为, 发现光照生成的SO₄^2-的µmol数值基本上为加入O₂的µmol数值的一半, 且反应后悬浮液的pH降低^[3]。     

Synthesis,Structure and Fluorescent Property of a Cadmium (II) Polymer

1 INTRODUCTION In recent years, lots of studies on the poly- nuclear cadmium compounds[1, 2] have been carried out carefully for their novel open-framework stru- cture motifs with channels and good fluorescent properties[3, 4]. Some organic bridging lig…     

Syntheses and Structures of Two Cadmium Complexes with Isophthaloylbisglycine Acid and 4,4'-Bipyridine

The two title complexes [{Cd（IBG-CH3）（4,4＇-bipy）（H2O）2}·NO3]n 1 and [{Cd（IBG）- （4,4＇-bipy）（H2O）2}·2H2O]n 2 （H2IBG = isophthaloylbisglycine and 4,4＇-bipy = 4,4＇-bipyridine） have been synthesized and characterized by single-crystal structure determination,IR and TG analyses. Complex 1 crystallizes in monoclinic,space group C2/c with a = 27.221（2）,b = 11.6093（7）,c = 16.3571（9）A,V = 5149.2（6） A^3,Z = 8,C23H23N5O11Cd,Mr = 657.86,Dc = 1.697 g/cm^3,F（000） = 2656.00,μ（MoKα） = 0.919 mm^-1,the final R = 0.0478 and wR = 0.0882 for 3728 observed reflections with I 〉 2σ（I）. Complex 2 crystallizes in triclinic,space group Pī with a = 9.0940（4）,b = 11.6852（5）,c = 13.1119（6）A,V = 1230.26 A^3,Z = 2,C22H26N4O10Cd,Mr = 618.87,Dc = 1.671 g/cm^3,F（000） = 628.0,μ（MoKα） = 0.951 mm^-1,the final R = 0.0567 and wR = 0.1124 for 3713 observed reflections with I 〉 2σ（I）. In both structures,the CdII metal centers are coordinated by seven atoms to form a distorted pentagonal bipyramidal geometry.     

Synthesis, Characterization and Fluorescence of a One-dimensional Cadmium（Ⅱ） Compound Involving Covalent and Hydrogen Bonds

1 INTRODUCTION The rational design and synthesis of new metal- organic coordination polymers have generated con- siderable interest in supramolecular chemistry and material science owing to their intriguing structural diversities and potential applications as functional materials[1～3]. Molecular self-assembly has been pro- ved to be an efficient way to construct various inte- resting coordination polymers[4～6]. The coordina- tion covalent bond, hydrogen bond or other mole- cular interact…     

Synthesis, Characterization and Fluorescence of a One-dimensional Cadmium( Ⅱ ) Compound Involving Covalent and Hydrogen Bonds

The title compound [Cd(Hq)2(Hdpa)2] (Hq = 8-hydroxyquinoline, H2dpa = diphenic acid) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 20.6880(5), b = 14.2584(4), c = 13.4776(4) (A), β = 113.434(2)°, C46H28Cd1N2O10, Mr = 881.10, V = 3647.68(17) (A)3, Z = 4, Dc = 1.604 g/cm3, F(000) = 1784,μ = 0.668 mm-1, the final R = 0.0576 and wR = 0.1157 for 2631 observed reflections with I ＞2σ(Ⅰ). The centrosymmetric Cd(Ⅱ) ion is six-coordinated in a slightly distorted octahedral geometry.The intermolecular hydrogen bonds extend the mononuclear structure into a one-dimensional supramolecular framework. The fluorescence spectrum of the compound exhibits intense emission at 520 nm when excited at 330 nm in solid state at room temperature.     

Synthesis and Characterization of a Two-dimensional Cadmium(II) Compound Involving Covalent and Hydrogen Bonds

1INTRODUCTIONThecrystalengineeringofmetal-organiccom-plexeswithfunctionalbuildingblocksisofgreatin-terestduetotheirintriguingstructuresandpotentialapplicationsinmaterialsciences[1,2].Thecoord-inationcovalentbond,hydrogenbondorothermolecularinteractionsand…     

Synthesis,Crystal Structures and Catalysis of Dinuclear Cd(Ⅱ) Complexes Bridged by Unusual (N,O,O′)-Coordinated α-Amino Acids

Four dinuclear amino acid cadmium(Ⅱ) complexes [Cd₂(tren)₂(dl-alaninato)](ClO₄)₃·H₂O(Ⅰ), [Cd₂(tren)₂·(l-alaninato)](ClO₄)₃·H₂O(Ⅱ), [Cd₂(tren)₂(dl-phenylalaninato)](ClO₄)₃(Ⅲ) and [Cd₂(tren)₂(l-phenylalaninato)]· (ClO₄)₃(Ⅳ), constructed from mixed ligands of tris(2-aminoethyl)amine(tren) and racemic or natural amino acids( amino acids=dl- or l-alanine, and dl- or l-phenylalanine), have been synthesized and characterized by X-ray crystallography. The structural analysis of complexes Ⅰ and Ⅲ reveals that the cadmium centers are coordinated by one tren ligand and one amino acid molecule with the unusual (N,O,O′)-bridged mode, resulting in asymmetric chromophores of CdN₄O and CdN₅O in complex Ⅰ, CdN₄O₂ and CdN₅O in complex Ⅲ, respectively. The utility of the four complexes as efficient water-compatible Lewis acid catalysts for the direct aldol reaction in water was examined. The reaction proceeded smoothly to afford the corresponding β-hydroxy ketones in up to 99% yield. Moreover, the diastereoselectivity of the reaction favors the formation of the syn-isomers.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)2]·2CH3OH}n Generated from Cadmium(Ⅱ) and Carbamyldicyanomethanide Anion Bridging Ligand

The three-dimensional coordination polymer {[Cd(cda)2](2CH3OH}n has been syn- thesized by Na(cda) (cda = carbamyldicyanomethanide anion) and hydrated cadmium perchlorate in methanol solution. The crystal belongs to monoclinic, space group C2/c with a = 15.686(3), b = 8.1650(18), c = 13.119(3) (A), β= 119.334(2)°, V = 1464.8(6) (A)3, Z = 4, C10H12CdN6O4, Mr = 392.66, Dc = 1.780 g/cm3, F(000) = 776 and μ = 1.516 mm-1. The structure was refined to R = 0.0248 and wR = 0.0628 for 1176 observed reflections (I ＞ 2σ(I)). The Cd(II) ion is coordinated by two amide- oxygen and four nitrile-nitrogen atoms from six different cda bridging ligands, forming a three- dimensional structure.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)_2]·2CH_3OH}_n Generated from Cadmium(II) and Carbamyldicyanomethanide Anion Bridging Ligand

1 INTRODUCTION The polynitrile-ligands, such as TCNE, TCNB, TCNQ, TCNP, tcm, dca and so on, are of ideal multi-functional bridging ligands. Many complexes with poly-nitriles as bridging ligands and uncoor- dinated ligand (electron acceptors) display dist…