Reactive Surfactant in the Emulsion Copolymerization of Methyl Methacrylate and Octyl Acrylate

The emulsion copolymerization of methyl methacrylate and octyl acrylate was studied using a reactive surfactant ammonium sulfate allyloxy nonylphenoxy poly(ethyleneoxy) (10) ether (DNS‐86), and a conventional surfactant sodium dodecylbenzene sulfonate (DBS) with a similar structure as a comparison sample. A series of latex samples have been prepared with two kinds of surfactants, and their properties have been characterized and compared. ¹H‐NMR proves that the reactive surfactant has been incorporated into the resulting copolymers. The atomic force microscopy (AFM) proves that the reactive surfactant DNS‐86 migrate to the surface of the latex film to a much less degree than the conventional surfactant DBS. Transmission electron microscopy (TEM) demonstrates that there are some differences in the particle morphologies. The stability and water‐resistance of the latex films prepared by reactive surfactant DNS‐86 are better than those prepared by the conventional surfactant DBS.     

STUDY OF THE PHOTOINITIATED CATIONIC POLYMERIZATION OF 3,4-EPOXY-1-BUTENE

The photopolymerization of 3,4-epoxy-1-butene (1) was investigated using Fourier transform real-time infrared spectroscopy (FT-RTIR). The effects of photoinitiator structure and concentration and light intensity on the photopolymerization were investigated. Compared to related epoxide monomers, 1 was shown to be more reactive and this was ascribed to stabilization of the growing cationic chain end by the double bond during the ring-opening polymerization. Epoxide 1 was also shown to be useful as a reactive diluent in the photopolymerization of multifunctional epoxides and was observed to accelerate the polymerization of less reactive epoxy monomers.     

Sydnone Ring as an ortho-Director of Lithiation, 3: One-Pot Regiospecific o-Acylation and Subsequent Sydnone 4-Substitution

Readily available 3-phenylsydnone (1) reacts with n-butyllithium/N,N,N′,N′-tetramethylethylenediamine (TMEDA) to form the dilithio species 2, which can be acylated regiospecifically at the ortho-aryl position using N-methoxy-N-methylamides (Weinreb's amides) followed by reaction with a second, more reactive electrophile at the sydnone C-4 position. Asymmetrically substituted arylsydnones 7 are obtained in 57–86% yield.     

磺酸咔咯及其镓(Ⅲ)配合物与DNA的相互作用和光核酸酶活性

本文用紫外-可见光谱、荧光光谱、圆二色光谱和粘度法研究了2,17-二(磺酸钠基)-5,10,15-三(五氟苯基)咔咯(1)及其镓配合物(1-Ga)与小牛胸腺DNA(ct-DNA)的相互作用。结果表明1和1-Ga通过外部结合的方式与ct-DNA相互作用,且结合能力1-Ga比1大。琼脂糖凝胶电泳实验显示1和1-Ga均具较好的光核酸酶活性,1-Ga光断裂DNA效果比1好,其光断裂机理与羟基自由基的产生有关。     

Synthesis and Chemical Reactivity of 5-Methoxy-2-vinyl-4-azaindoles

2-Vinyl-4-azaindoles are less reactive with dienophiles than 2-vinylindoles. 5-Methoxy-2-vinyl-4-azaindole 2a and its 1-methyl derivative 2a reacts with N-phenylmaleimide to yield cycloadducts only under vigorous conditions. 2b produces a cycloadduct with dimethyl acetylenedicarboxylate, while 2a yields a Michael-type adduct. Reactions with more reactive dienophiles gave only polymeric products.     

Mannich Reactions of Cephalosporin Sulphoxides and Sulphones with Imonium Salts. An Improved Synthesis of 2-Methylene-cephalosporins

2-Methylenecephem-1-oxides (4) or -1,1-dioxides (6) can be very conveniently obtained through the use of dimethyl(methylene)imonium salts, which can be prepared in situ or in advance from bis(N,N-dimethylamino)methane (2) and a reactive acid derivative.     

PET/LDPE REACTIVE COMPATIBILIZATION THROUGH THE CARBAMATE FUNCTIONALIZED EPM

ABSTRACT

To investigate the effect of reactive compatibilization in the immiscible poly(ethylene terephthalate) (PET)/low-density polyethylene (LDPE) blend, ethylene-propylene copolymer-g-methacryloyl carbamate (MEPM) was prepared and used as a reactive compatibilizer. The inter-facial reaction of carbamate group in MEPM with OH/COOH in PET was confirmed by measuring the interfacial tension between the PET and LDPE using the breaking thread method. The two-step blending process strongly influenced the blend morphology at high concentration of the dispersed phase in the blend. The MEPM showed a discrepancy in the reactive compatibilization ability with a blend sequence in the blends of different dispersed phase concentration.     

A Facile Approach To 5-Trifluoromethylated 1,2,4-Triazole Derivatives

Ethyl (l,l,l-trifluoro-2-propylidene)carbazate is converted with tert-butyl hypochlorite to the 2-chloro-l,l,l-trifluoro-2-propyl azo compound 2, which reacts with antimony pentachloride to produce the trifluoromethylated 1-aza-2-azoniaallene salt 3 as a highly reactive intermediate. The cation 3 is employed as a CF₃-containing synthon for the preparation of the 5-trifluoromethylated 1H-1,2,4-triazoliumpicrates 6a-e.     

Rapid and Efficient Microwave‐Assisted Synthesis of N‐Carbamoyl‐L‐amino Acids

A rapid and efficient method for the synthesis of N‐carbamoyl‐L‐amino acids is reported. The procedure, involving the reaction between urea and α‐amino acids sodium salts, was performed under microwave conditions using an unmodified domestic microwave oven. A careful study of the operative conditions indicated proline (1d) as the less reactive substrate and phenylglycine (1e) as the more reactive one among all the α‐amino acids tested. Substitution of urea with potassium cyanate produced a low conversion into the corresponding N‐carbamoyl derivative, and a possible explanation of this result is reported.     

一种快速响应的线粒体靶向荧光探针用于检测活细胞和斑马鱼中的次氯酸盐

以香豆素为荧光团,设计并合成了一种线粒体靶向荧光探针Cou-Py,用于检测ClO^-。由于肟基在激发态的C=N异构化,Cou-Py表现出非常微弱的荧光,能够实现ClO^-促发的脱氧反应,在5 s内实现荧光恢复。此外,Cou-Py对ClO^-表现出高的选择性和低的检测限（6.87 nmol·L^-1）。重要的是,Cou-Py已成功用于检测MCF-7细胞线粒体和斑马鱼幼虫中的ClO^-。     

An Influence of Structure of Ester on Results of Its Macrocyclization Reaction with α,ω-Diamine

Abstract

Sodium methoxide was found to be an excellent catalyst in the reaction of diesters with diamines leading to macrocyclic diamides. Time of reaction was shortened to several hours (in the case of reactive esters) or to several days (in the case of less reactive esters). The template effect of Na⁺ ion was excluded. It was also proposed that the electron density on the carbonyl group in various esters was responsible for different results of amidation reactions. Decrease in electron density increases the reactivity of the carbonyl group. For esters 1–5, the inductive effect of the heteroatom at the α position to the carbonyl group influences reactivity mostly.     

Specific chemical behavior of NdII and DyII iodides in reactions with aromatic compounds

Benzene, toluene, tert-butylbenzene, or biphenyl virtually do not react with NdI₂ (1) or DyI₂ (2) in THF at –20 °C but appreciably accelerate the reactions of these salts with solvents, resulting in LnI₃ and intractable mixtures of products of the general composition [LnI(H)(R)(THF)] (R are fragments of the THF molecule). The same effect is induced by the addition of diphenylmercury or tetraphenyltin to solutions of 1 or 2. Phenol easily oxidizes 1 and 2 to give at 0 °C the PhOLnI₂(THF) _x complexes (x = 3, 4) in 55—95% yields. At –90 °C, iodide 2 is converted into a similar complex PhODyI₂(THF)₄, whereas 1 gives a mixture of PhONdI₂(THF)₄, (PhO)₂NdI(THF)₅, NdI₃(THF)₃, and [NdI(H)R(THF)]. A plausible pathway of the reactions including the intermediate formation of extremely reactive monovalent lanthanide iodides LnI is discussed.     

Synthesis,Characterization and reactivities of Schiff-base complexes of Ruthenium(III)

Schiff-base complexes of ruthenium (1–5) have been synthesized using Schiff-base ligands derived by condensation of either 1,2-phenylenediamine with aldehydes (salicyldehyde, 2-pyridinecarboxaldehyde) or acetylacetone with amines (2-aminophenol, 2-aminomethylpyridine). All complexes were characterized by analytical, spectroscopic, conductance, magnetic moment and electrochemical studies. At room temperature, complexes 1–5 catalyze the oxidation of both saturated and unsaturated hydrocarbons using tert-butylhydroperoxide (t-BuOOH). A mechanism involving formation of and transfer from a reactive high valency Ru(V)-oxo species as the catalytic intermediate is proposed for the processes.     

Interaction of Tris(3-Hydroxymethyl)Phosphine with Cinnamic Acids

Abstract

Phosphonium zwitterions of the known type R₃P⁺CH(Ar)CH₂CO₂ ^? (II) are obtained as a racemic mixture in moderate yield via a 1:1 reaction of cinnamic acids (Ar = phenyl, or substituted phenyl) with [HO(CH₂)₃]₃P in acetone at room temperature under Ar. The products are characterized by elemental analysis, ³¹P{¹H}-, ¹H-, and ¹³C{¹H}-NMR spectroscopies, and mass spectrometry, although they contain a minor coproduct formed via neutralization of the positive and negative charges of II with the respective acid and phosphine reactants (see Experimental Section). In CD₃OD, the monodeuterated salts R₃P⁺CH(Ar)CH(D)CO₂ ^? are formed as a mixture of diastereomers with d.r. values of ～2 to 8, depending on substituent groups present in the organic acid; in these studies, 2-HO-cinnamic acid is the most reactive, and β-methylcinnamic acid is the least reactive.     

The kernel of DWBA transition amplitude in atom–diatom reactive scattering

The kernel of the distorted-wave Born approximation (DWBA ) transition amplitude will be explored with attention to the atom–diatomic molecule reactive scattering process of A + BC → AB + C. Our study of the kernel reveals valuable intrinsic properties regarding the state-to-state reactive scattering process. In particular, such a study will help us to better understand (i) the favored geometric configuration during collision, (ii) the spatial domain of contribution to the differential and total cross sections, and (iii) the structural dependence of the kernel distribution on the mass ratio of the reactant molecule BC and the departing atom C, particularly in the case of colinear rearrangement collisions. In this study we choose the FH₂ system as an illustration.     

Synthesis of Anabaseine and Anabasine Derivatives: Structural Modifications of Possible Nicotinic Agonists

Coupling nicotinoyl chloride with 3,4‐dimetoxyphenethylamine under Bischler‐Napieralski cyclization afforded the isoquinoline (4) in good yield. This latter was used as starting material to obtain with only hydrobromic acid a product with demethylation at the position 7 (5). In addition, treatment of (4) with NaBH₄/MeOH gave 6,7‐dimetoxy‐1‐(pyridin‐3‐yl)‐1,2,3,4‐tetrahydroisoquinoline (6) and unexpectedly, under mild reduction of the pyridine moiety with H₂/PtO₂/AcOH/, gave 6,7‐dimetoxy‐1‐(piperidin‐3‐yl)‐1,2,3,4‐tetrahydroisoquinoline (7) as the title compound. The unusual chemical reactivity of 4 onto acidic conditions and catalytic hydrogenation allowed us to obtain anabaseine and anabasine derivatives under mild conditions.     

Unusual Regioselectivity in the Reactions of Chlorocyclophosphazene-Containing Crown Ethers with Dinucleophiles

Abstract

New macrocyclic ligands with cyclophosphazene sub-units, representing geminally diamino-bridged derivatives of BINO-crown type (III), and bisansa-cyclosubstituted ones of chiral PNP cryptand type (IV) have been obtained by the regioselective substitution reactions of monoansa(oxytetraethylenoxy) reactive PNP-crown, N₃P3CI₄[O(CH₂CH20)₄] (II) with the dinucleophiles, like alkylenediamines or sodium diarylates. The supramolecular control of these processes is discussed.     

Silicon,Boron and Arsenic Derivatives of Phosphorus(Iv) Thioacids in Synthesis of Novel Organothiophosphorus Compounds

Abstract

We have found that S-boron 0-alkyl(ary1)dithiophosphonates react with organic substances containing reactive multiple bonds such as methyl acrylate, vinyl butyl ether, vinyl acetate under mild conditions to form products of insertions into the S-B bond. The similar results were obtained in the case of S-arsenic 0-alkyl(ary1)dithiophosphonates.     

4-Alkoxycarbonyl-2-(2-pyridyl)thiazoles and their complexes with CuII and CoII. Molecular and crystal structure of copper 4-ethoxycarbonyl-2-(2-pyridyl)thiazole dichloride

The first synthesis of ethyl 2-(2-pyridyl)thiazole4-carboxylate ( 2) and bis[2-(2-pyridylthiazol-4-ylcarbonyloxy)ethyl] disulfide ( 4) is described. The complexation of compounds 2 and 4 with Cu^II, Co^II, and Ni^II chlorides and perchlorates has been studied. Electrochemical behavior of the ligands and complexes obtained has been investigated by cyclic voltammetry and using rotating disk electrode, which allowed us to confirm the possibility for the ligand 4 and its complexes to be adsorbed on the surface of a gold electrode.     

New Routes to (E)-Halophosphaalkenes

Abstract

Starting from dihalophosphaalkenes Mes?P=CHal₂ (Hal = Cl, Br, I) we have been developing methodologies for the synthesis of (E)-Mes?P=CHHal, which can be converted to reactive phosphaalkenyl metal reagents. Dibromophosphaalkene 1 was reacted with n-butyllithium at -120 °C, furnishing 2 after chlorination of the intermediate carbenoid. Compound 2 was transformed to the (E)-chlorophosphaalkene 3 as shown (SCHEME 1).