Enantiomere der 2,2'-dinitrobiphenyl-6,6'- dicarbonsäure als stereoselektiv wirksame,reversible schutzgruppen-I : Zur stereospezifität der synthesen von s-(+)- und r-(-)- noradrenalin und adrenalin

Diaminoethanone derivatives with sterically rather fixed prochiral carbonyl moieties were synthesized by acylation of 1-(3,4-dihydroxyphenyl)-1-oxo-2-aminoetahne and 1-(3,4-dihydroxyphenyl)-1- oxo-2-methylaminoethane with S-(-)- or R-(+)-1,1'-diphenyl-2,2'-dinitro-6,6'-dicarbonicc acid (2,2'-dinitro- 6,6'-diphenic acid). After reduction the analogous diamidoethanone derivatives were obtained, which have a centre of chirality. Removal of the protecting group yielded noradrenaline and adrenaline in different fractions of their enantiomers. The connection of this partial stereospecificity and the fixed conformation 2,2'- dinitro- 6, 6'-diphcrnic acid-diamidoethanone is discussed.     

Block copolymers with liquid crystalline segments

This paper describes the synthesis and characterization of polystyrene-block-poly(2,2'-dimethyl-4,4'-biphenylene phenylterephthalate)-block-polystyrene and of poly(ethylene glycol)-black-poly(2,2'-dimethyl-4,4'-biphenylene phenylterephthalate)-block-poly (ethylene glycol) block copolymers. The ABA-triblock copolymers were synthesized by condensation reaction of telechelic poly(2,2'-dimethyl-4,4'-biphenylene phenylterephthalate) with ω-hydroxy polystyrene and ω-hydroxy poly(ethylene glycol) methyl ether of different molecular weights prepared by anionic polymerization. Some aspects of the liquid crystalline behavior and the phase transitions with respect to the block copolymer composition will be discussed.     

铜三氟柳配合物的合成,结构和仿生催化溴化

合成了一系列2-羟基-4-三氟甲基苯甲酸（h₂tba）-铜配合物：[Cu（htba）₂（pz）₂]（1）,[Cu（htba）（2,2''-bipy）]（htba）（2）和[Cu（htba）₂（4,4''-bipy）]（3）（h₂tba=2-羟基-4-三氟甲基苯甲酸,pz=吡唑,2,2''-bipy=2,2''-联吡啶,4,4''-bipy=4,4''-联吡啶）,并且通过元素分析、红外光谱、紫外光谱、粉末X射线衍射、单晶X射线衍射和热重分析方法对配合物结构进行了表征。这些配合物能够在过氧化氢和溴化物存在的条件下催化苯酚红溴化,并且展示出了较高的催化溴化活性。     

2-氯-4-氟苯甲酸与5，5'-二甲基-2，2'-联吡啶镧系配合物的晶体结构、光谱和热行为

合成并表征了2个双核配合物[Pr （2-Cl-4-FBA）₃（5,5''-DM-2,2''-bipy）]₂（1）和[Dy （2-Cl-4-FBA）₃（5,5''-DM-2,2''-bipy）]₂·2（2-Cl-4-FHBA）（2）,其中2-Cl-4-FHBA=2-氯-4-氟苯甲酸,5,5''-DM-2,2''-bipy=5,5''-二甲基-2,2''-联吡啶。配合物1以八配位的Pr³⁺为中心,其周围的配位环境为扭曲的三角十二面体。配合物2的结构是独特的,它包含2个自由的2-氯-4-氟苯甲酸分子,并以九配位的Dy³⁺为中心与周围的氮、氧原子形成扭曲的三棱镜几何构型。这2个配合物均结晶于三斜晶系P1空间群,并通过氢键相互作用和π-π堆积作用形成了一维和二维超分子结构。研究了配合物的热分解过程,结果表明配合物1和2分别分为4步和5步进行分解。同时对配合物的三维红外堆积图进行了研究,结果表明,整个热分解过程中释放出的主要气态产物是水、二氧化碳和有机小分子碎片。配合物2的荧光性质研究表明,它可以发射出Dy³⁺的特征跃迁对应的荧光。     

铜三氟柳配合物的合成,结构和仿生催化溴化

合成了一系列2-羟基-4-三氟甲基苯甲酸（h₂tba）-铜配合物：[Cu（htba）₂（pz）₂] （1）,[Cu（htba）（2,2''-bipy）]（htba） （2）和[Cu（htba）₂（4,4''-bipy）] （3）（h₂tba=2-羟基-4-三氟甲基苯甲酸,pz=吡唑,2,2''-bipy=2,2''-联吡啶,4,4''-bipy=4,4''-联吡啶）,并且通过元素分析、红外光谱、紫外光谱、粉末X射线衍射、单晶X射线衍射和热重分析方法对配合物结构进行了表征。这些配合物能够在过氧化氢和溴化物存在的条件下催化苯酚红溴化,并且展示出了较高的催化溴化活性。     

Calculating the Gibbs Energies of Solvation of 2,2'-Dipyridyl in Nonaqueous Solvents

Russian Journal of Physical Chemistry A - The Gibbs energies of solvation of 2,2'-dipyridyl (2,2'-Dipy) in methanol (MeOH), acetonitrile (AN), dimethylsulfoxide (DMSO), and...     

Total synthesis of orellanine : The lethal toxin of Cortinarius Orellanus fries mushroom

The syntheses of the main toxin of Cortinarius Orellanus Fries, orellanine, and of its decomposition product, orelline, are reported. The structures of 3,3',4,4'-tetrahydroxy-2,2'-bipyridyl-N,N'-dioxide for orellanine and of 3,3',4,4'-tetrahydroxy-2,2'-bipyridyl for orelline have been proposed by W.Z. Antkowiak and W.P. Gessner. These two conpounds have now been synthesized starting from the 3,3',4,4'-tetramethoxy-2,2'-bipyridyl which could be obtained in good yields by the nickel-phosphine complex-mediated homo coupling of 2-bromo-3,4-dimethoxy pyridine according to the general procedure previously reported by us. The 3,3',4,4'-tetrahydroxy-2,2'-bipyridyl was obtained by demethylation with hydrobromic acid. The oxidation of this compound with hydrogen peroxide afforded the 3,3',4,4'-tetrahydroxy-2,2'-bipyridyl-N,N'-dioxide. This latter compound was also obtained by the demethylation of the 3,3',4,4'-tetramethoxy-2,2'-bipyridyl-N,N'-dioxide with hydrobromic acid. The products obtained presented physical and spectral properties identical to those of the natural products.     

Efficient Syntheses of New Super Lewis Basic Tris(dialkylamino)-Substituted Terpyridines and Comparison of Their Methyl Cation Affinities

Syntheses of very electron-rich dialkylamino-substituted 2,2':6',2''-terpyridines (TPYs) were adapted to moderate scale preparation without tedious purification of intermediates. The key 4'-bromo-6,6''-dimethyl-2,2':6',2''-terpyridine-4,4''-diyl bisnonaflate is now available in gram quantities. Its nucleophilic aromatic substitution with dimethylamine provided mixtures of 4'-bromo-substituted 4,4''-bis(dimethylamino)-TPY and the tris(dimethylamino)-TPY. The bromo compound was used in a Buchwald–Hartwig amination to provide the tris(dimethylamino)-TPY in excellent yield. The 4'-bromo substituent was reductively removed to furnish the bis(dimethylamino)-TPY. The same sequence of reactions with pyrrolidine as nucleophile leads to the hitherto unknown pyrrolidino-TPYs. Calculations at the MP2(FC)/6–31+G(2d,p)//B98/6-31G(d) level predict very high methyl cation affinities for compounds of this type, with the 4,4',4''-tri(pyrrolidin-1-yl)-TPY being the most Lewis basic TPY synthesized to date. The efficiently prepared electron-rich TPYs should be excellent ligands for many applications.     

Synthesis,Crystal Structure,and Electrochemical Properties of One Polyoxometalate-Based Silver(I) Compound with Keggin-Type [PW<Subscript>12</Subscript>O<Subscript>40</Subscript>]<Superscript>3−</Superscript> Anions

One polyoxometalate-based silver(I) compound [Ag(2,2'-Bipy)₂]₃(PW₁₂O₄₀) (I) (2,2'-Bipy = 2,2'- bipyridine) has been synthesized and structurally characterized by IR spectroscopy, elemental analysis, XRPD and X-ray single-crystal structure analysis (CIF file CCDC no. 1572216). Compound I exhibits a crystalline three-dimentional supramolecular framework constructed by Ag-2,2'-Bipy coordination units and [PW₁₂O₄0]^3? template anions, in which there are multiform π...π interactions and hydrogen bonds. The cyclic voltammetric experiments show that compound I displays a good electrocatalytic activity toward the reduction of nitrite.     

Synthesis of conjugates of 5,15-disubstituted aminoporphyrins and terpyridine derivatives with potential chelating properties

meso-Arylporphyrin containing two external chelating 2,2':6',2'-terpyridine fragments and its zinc complex were synthesized. The key step comprised the amide bond formation between the porphyrin diamine derivative and 4'-(4-carboxyphenyl)-2,2':6',2'-terpyridine. The compounds obtained seem to be potent for photodynamic therapy and diagnosis.     

Novel Iron-Based Polynuclear Metal Complexes [FeII(L)(CN)4]2–[FeIII(H2O)3Cl]2: Synthesis and Study of Photovoltaic Properties for Dye-Sensitized Solar Cell

A series of novel polynuclear iron-based photosensitizers (1–3) with cyano-bridged to form a molecular square were synthesized and their optical, electrochemical, and photovoltaic properties were investigated. The modification of anchoring groups with 4,4'-dicarboxy-2,2'-bipyridine, 2,2'-bipyridine, and 4,4'-dimethoxy-2,2'-bipyridine does not show significant changes on the both absorption and electrochemical properties of these iron-based dyes. This indicates that the polynuclear iron-based photosensitizers have better flexibility to regulate their physical properties of solubility, surface absorption, and thin-film formation for device preparation. The polynuclear new dyes show power conversion efficiencies ranged from 0.43 to 0.48% that is almost the best system among the published iron-based photosensitizers. These iron-based dyes were able to chemisorb on TiO₂ surface efficiently and then promoting electron injection and photocurrent generation in a dye-sensitized solar cell with solar irradiation.

     

四溴双酚A-双(2,3-二溴丙基醚)的绿色合成

本文探索了水相中烯烃与溴的加成反应,以四溴双酚A双烯丙基醚为原料,在水相中合成四溴双酚A-双(2,3-二溴丙基)醚,通过考察助剂类型及用量、溴的用量、反应时间、反应温度等因素,优化反应条件,产品收率可达到93.6%,通过HPLC检测纯度达到91.7%。本文借助十二烷基硫酸钠不仅解决了原料不溶于水导致产品团聚的问题,而且此方法后处理简单,无废液产生,简化了工艺路线,可有效降低成本。     

Similarities of Coordination Polymer and Dimeric Complex of Europium(III) with Joint and Separate Terpyridine and Benzoate

A dimeric complex of trivalent europium [Eu₂Cl₄(bc)₂(ptpy)₂] ( 1 ), containing the separate ligands 4'-phenyl-2,2':6',2''-terpyridine (ptpy) and benzoate (bc^–) and a one-dimensional double strand coordination polymer of the composition ¹_∞[EuCl₂(cptpy)] ( 2 ) with 4-[2,2':6',2''-terpyridin]-4'-yl-benzoate (cptpy^–) were obtained. The products exhibit structural similarities despite the character of joint and separate functionality of the ligands. The dimer 1 shows photoluminescence with high quantum yield [61(2) %]. Eu³⁺ emission lifetime is 1.493(1) ms at room temperature and rises to 1.649(1) ms upon cooling to 77 K.     

Asymmetric Ring-Opening of Cyclohexene Oxide with Mercaptan (Thiophenols) Catalyzed by Chiral Schiff Base/Ti(OPr- i ) 4 or (−)-(S)-Binaphthol/Ti(OPr- i ) 4

New chiral Schiff base ligands 1-4 were synthesized starting from (+)-camphor and (+)-1-(4-nitrophenyl)-2-amino-1,3-propanediol, and their application in asymmetric ring-opening of cyclohexene oxide using mercaptan (thiophenols) as nucleophiles was investigated. The aymmetric ring-opening of cylohexene oxide catalyzed respectively by chiral Schiff bases 1-4 /Ti(OPr- i ) 4 and ( m )-(S)-1,1'-binaphthalene-2,2'-diol 5 /Ti(OPr- i ) 4 complex afforded the corresponding chiral g -hydroxysulfides 6-10 in lower to good yield with lower to moderate ee values. Moreover, the using of ( m )-(S)-1,1'-binaphthalene-2,2'-diol as ligand led to better chiral induction effect.     

Synthesis,Characterization and Crystal Structure of a One-Dimensional Chain Copper Bipyridine Complex Bridged Through an Azobispyridine Ligand

The copper complex {[Cu(2,2'-bpy)(azpy)(H₂O)(ClO₄)} _n 1 (2,2'-bpy=2,2'bipyridine, azpy=4,4'-azopyridine), has been synthesized and characterized. X-ray analysis reveals that copper is coordinated by two N atoms of 2,2'-bpy, two N atoms from two bridging azpy ligands, one O atom of coordinated water and O atom from ClO-₄ and has a distorted octahedral coordination environment in complex 1. Copper ions are linked to each other through bridging azpy ligands to form a one-dimensional chain. Stacking the one-dimensional chains results in the formation of rhombic channels with ca. 6Å x 6Å. Variable-temperature magnetic susceptibility studies show that there is a weak antiferromagnetic interaction between the copper ions.     

One-pot synthesis of cyclopentane-fused 5&#x27;-aryl-4-cycloalkylamino-2,2&#x27;-bipyridines via the aza-Diels–Alder/SNipso reactions

One-pot synthesis of cyclopentane-fused 5'-aryl-4- cycloalkylamino-2,2'-bipyridines based on the neat (200 °C) reaction of 3-(4-bromopyridin-2-yl)-1,2,4-triazines with enamines is reported. In the course of the transformation, consecutive aza-Diels–Alder reaction and nucleophilic substitution of bromine atom under the action of the liberating amine occur. The possibility of the solvent- and catalyst-free replacement of 4-positioned bromine atom in 2,2'-bipyridines by amino moieties was demonstrated.     

Pyrrole studies. : Part 36 The synthesis of 2,2'-bipyrroles and related compounds

Nucleophilic addition to but-1-en-3-one by the acyl anion equivalent of 2-formylpyrroles, generated by reaction with thiazolium salts, yields 1-(2-pyrrolyl)pent-1,4-diones, which undergo the Paal-Knorr reaction with ammonia and primary amines to give the 2,2'-bipyrroles. Alternatively, the 2,2'-bipyrrole system can be obtained by pyrolysis of 2-azido-5-(2-pyrrolyl)penta-2,4-dienoic esters.     

Oxidation of 4-methoxy-1-naphthol on promoted platinum catalysts

Oxidative coupling of naphthols is a useful method for the formation of new carbon-carbon bonds in organic synthesis. In the presence of hydrogen peroxide, platinum supported on activated carbon catalyses this reaction. The outcome is influenced by the solvent, the reaction temperature and the physical structure of the catalyst. The catalyst structure is determined by the synthesis method and the modifier used (Bi or Sb). Within 40 min 4-methoxy-1-naphthol can be converted to 4,4'-dimethoxy-2,2'-binaphthalenyl-1,1'-diol with a yield of up to 94%, or to 4,4'-dimethoxy-2,2'-binaphthalenylidene-1,1'-dione with a yield of 92%. High amounts of quinoid byproducts (≤22%) are observed in nitromethane as the solvent.     

Synthesis,Complexation and Photophysics in Protic Solvents of Lanthanide Complexes of Novel Calix[4]arene Polycarboxylic-2,2′-bipyridine Mixed Ligands

Two novel cone calix[4]arene ligands 11a and 11b bearing two iminodiacetic chelating units and two C 6 or C 5 substituted 2,2'-bipyridine chromophores in diametral position at the lower rim were synthesized. These ligands form complexes with lanthanide ions in methanol solution whose stability (4.5<log K ass <6.2) depends on the substitution pattern (C 6 or C 5 ) of the 2,2'-bipyridine units. Contrary to that observed with other neutral calixarene ligands, the luminescence properties of the Eu 3+ and Tb 3+ complexes are not very much affected by the type of the 2,2'-bipyridine chromophore. Luminescence lifetimes (0.31 ms< <1.1 ms) and quantum yields (0.017< { <0.130) are higher for Terbium compared with the corresponding Europium complexes.     

Synthescs and some reactions of N,N'-diamino-2,2′- and −4,4′-bipyridinium salts

The syntheses and some reaetions of N,N'-diamino-2,2′- and 4,4′-bipyridinium salts (IV, V and VI) are described. These compounds are prepared by the reaction of bipyridyls (I-III) with O-mesitylenesulfonylhydroxylamine in moderate to good yields. Compounds IV and VI were found to give the N,N'-diacyl derivatives by the reaction with acyl chlorides and to undergo 1,.3-dipolar cycloaddition reaction with an acetylenic compound to give 1:2 adducts. Photo-irradiation of N,N'-dibenzoylimino-2,2′-bipyridinium betaine (IX) isomerizes to a mono diazepine derivative (XVI).