Oligo(glycerol) Methacrylate Macromonomers

Linear, protected ω‐methoxy oligo(glycerol) methacrylate (OGly^PMA) macromonomers are synthesized via anionic ring‐opening polymerization of ethoxyethyl glycidyl ether (EEGE) followed by termination with methacrylic acid anhydride ( = 3–11, PDI < 1.30). The covalently bound methacrylate moiety allows the homopolymerization of OGly^PMA as well as copolymerization with low molecular weight comonomers. In homopolymerizations, macromonomers are polymerized by atom transfer radical polymerization (ATRP) yielding well‐defined graft polymers ( = 20 000–30 000 g mol⁻¹). Acidic hydrolysis of the protecting groups releases water‐soluble polyhydroxy‐functional structures. First results on the copolymerization with 2‐hydroxyethyl methacrylate (HEMA) are given in the final part of this work.     

Polymerization of vinyl monomers by a new oligoperoxide: Oligo(adipoyl-5-peroxy-2,5-dimethyl n-hexyl peroxide)

A new polymeric initiator, oligo(adipoyl-5-peroxy-2,5-dimethyl n-hexyl peroxide), was synthesized by interfacial condensation of adipoyl chloride with 2,5-dimethyl-2,5-dihydroperoxy hexane. This can be used as an initiator to prepare block copolymers by free radical mechanism in a procedure involving several steps, since the colorless, viscous liquid, oligoperoxide, has 8–10 peroxide groups per molecule. The thermal decomposition of this oligoperoxide in benzene solution at 98°C was first order and its half life was 9.75 h. The results of the polymerization kinetics show that this oligoperoxide lies in between of 2,5-dimethyl-2,5-dihydroperoxyhexane and benzoyl peroxide for empirical polymerization rates of styrene and methyl methacrylate at 80°C.     

基于环己烷二甲醇和低聚乳酸制备脂肪/芳香共聚酯

通过对苯二甲酸二甲酯(DMT),1,6-己二醇(HDO),以及1,4-环己烷二甲醇(CHDM)和-羟基--羧基DL-低聚乳酸(OLA)在催化剂钛酸四丁酯下熔融缩聚合成了一系列可生物降解共聚酯PHCTL。通过核磁共振(1H NMR),差示扫描量热法(DSC),热重分析法(TG)和广角X射线衍射(WAXS)技术对共聚酯进行了表征,随着CHDM含量的增加,共聚酯的熔点(Tm),热分解温度(Td)等都有了明显的增加。凝胶渗透色谱(GPC)分析得出共聚酯的分子量在1.7-3.6  x104之间。在37 C下 PHCTL共聚酯发生了明显的降解,降解速率的大小与共聚酯的亲水性有关。     

齐聚苯撑乙烯/MCM-41纳米复合材料的制备

制备了一种齐聚苯撑乙烯(OPPV)/MCM-41复合材料. 氮气吸附等温线结果证明了OPPV被成功包覆在MCM-41中. 紫外-可见光谱结果表明, OPPV以近乎单分散的状态分布在MCM-41孔道中. 荧光光谱结果表明, 与OPPV相比, OPPV/MCM-41复合材料具有更强的光稳定性和更高的发光效率.     

Automated Solid-Phase Oligo(disulfide) Synthesis

A method for automated solid-phase synthesis of oligo(disulfide)s was developed. It is based on a synthetic cycle comprising removal of a protecting group from a resin-bound thiol followed by treatment with monomers containing a thiosulfonate as an activated precursor. For ease of purification and characterization, the disulfide oligomers were synthesized as extensions of oligonucleotides on an automated oligonucleotide synthesizer. Six different dithiol monomer building blocks were synthesized. Sequence-defined oligomers of up to seven disulfide units were synthesized and purified. The sequence of the oligomer was confirmed by tandem MS/MS analysis. One of the monomers contains a coumarin cargo that can be released by a thiol-mediated release mechanism. When the monomer was incorporated into an oligo(disulfide) and subjected to reducing conditions, the cargo was released under near-physiological conditions, which underlines the potential use of these molecules in drug delivery systems.     

Preparation of soluble and fusible poly(2,5-dimethoxy-1,4-phenylene)

Poly(2,5-dimethoxy-1,4-phenylene) was prepared by oxidative polymerization of p-dimethoxybenzene with aluminum chloride and copper(II) chloride in nitrobenzene under reduced pressure. The polymers obtained were soluble in sulfuric acid and fusible at 320°C. The intrinsic viscosity of the polymer was ca. 0.07 in sulfuric acid. Demethylation of methoxy groups did not occur during the polymerization.     

Oligo(fluorenyleneethynylenegermylene)s and their metallopolymers

Oligo(fluorenyleneethynylenegermylene)s and their polyplatinynes are synthesized and photophysically characterized; inclusion of heavy germylene bridges greatly boosts the phosphorescence decay rate in metallopolymers.     

Heck Synthesis of New Organosilicon Oligo(arylenevinylenes)

Russian Journal of Organic Chemistry - Two alternative synthetic approaches to new silicon-containing oligo(arylenevinylenes), 1,4-bis-{(E)-2-[4-(trimethylsilyl)phenyl]ethenyl}benzene and...     

Synthesis and Properties of Oligo(p-tolyliminomethyl)phenol

The conditions and products of oxidative polycondensation of 2-(p-tolyliminomethyl)phenol in alkaline aqueous solution in the presence of sodium hypochlorite or atmospheric oxygen were studied. The optimal conditions were found, and procedures for preparing oligo(p-tolyliminomethyl)phenols were developed. The composition and structure of the products were determined by chemical and spectroscopic methods.     

2-(Dialkoxyphosphinothioyl)thio-1,3,2-dioxoborolanes and -borinanes

Russian Journal of General Chemistry -     

Stereocontrolled Synthesis of Oligo(nucleoside phosphorothioate)s

Encouraging results obtained for modulation of gene expression by antisense oligonucleotides and their analogues have kindled hopes for a new generation of therapeutics against viral infections, cancer, and many other diseases. Among such analogues, oligo(nucleoside phosphorothioate)s (Oligo-S) have generally shown the highest efficacy in inhibiting the biosynthesis of “unwanted” proteins. The first clinical trials of antisense agents are now in progress using Oligo-S against genital warts and acute myeloid leukemia, and tests of Oligo-S against AIDS should follow soon. Nevertheless, their mechanism of action, internalization, cellular trafficking, subcellular localization, and interaction with cellular proteins is still poorly understood. It is assumed a priori that application involves rapid and efficient molecular recognition of target RNA by Oligo-S; however, the effects of the chirality of Oligo-S have so far been unappreciated, because Oligo-S has not yet been synthesized with stereocontrol. Indeed, the diastereomeric composition of Oligo-S has never been determined, primarily because of the lack of appropriate analytical methods. Since each of the diastereomers is a stereochemically unique chemical entity, questions arise as to which diastereomer is responsible for an observed biological response, including positive (curative) or possibly negative (toxic) side effects. In this review we intend provide a perhaps somewhat speculative assessment of the problems associated with the stereo-controlled synthesis of Oligo-S and to discuss the state-of-the-art in this field including strategies that may lead to Oligo-S of predetermined chirality. This article is not intended to discourage researchers from further studies of dia-steromeric mixtures of Oligo-S as potential pharmaceuticals. Throughout the history of medicinal chemistry numerous useful medicines were discovered, developed, and employed without the detailed knowledge of their structure. Indeed, the composition of the vaccines discovered by Pasteur is a subject of vigorous study still today.     

Synthesis and Amination of Oligo(trifluoromethanesulfonyl)dinaphthylmethanes

Russian Journal of General Chemistry -     

Synthesis of Oligo (Phenyleneoxide) by Electro-Oxidative Polymerization

Anodic oxidation of 2,6-disubstituted phenols gave poly(2,6-disubstituted-1,4-phenyleneoxide)s quantitatively by using dichloromethane and tetraethyl ammonium bromide as the solvent and the supporting electrolyte respectively. Phenol was also electro-oxidatively polymerized to yield oligo(1,4-phenyleneoxide) with molecular weight of 1200～2500. The 2-step polymerization and the polymerization in the presence of bisphenol were carried out to increase the molecular weight of the oligo(phenyleneoxide). The mechanism of the electro-oxidative polymerization was discussed by electrochemical and ESR measurements.     

Oligo(p-phenyleneethynylene)s with hydrogen-bonded coplanar conformation

A series of monodispersed oligo( p-phenyleneethynylene)s were synthesized bearing intramolecular hydrogen bonds between side chains of adjacent phenylene units in the backbone. Thus, all repeating units of the molecules are constrained in a coplanar orientation. Such planarized conformation is considered favorable for single-molecule conductance. Photophysical characterization results show narrowed bandgaps and extended conjugation lengths, consistent with a rigid, planar backbone framework as a result of intramolecular hydrogen bonding.