N-(带有不同离去基团的二供电子链)邻苯二甲酰亚胺衍生物的光诱导单电子转移环化反应

同时含有末端乙氧基醚支链和末端三甲基硅聚乙氧基醚支链的邻苯二甲酰亚胺衍生物1在高氯酸的甲醇溶液中发生光诱导单电子转移(SET)反应,以很高的反应区域选择性和很好的产率得到由末端三甲基硅聚乙氧基醚链环合构成的环状化合物.所有新化合物均经NMR和EI-MS确定其结构.     

氢氧化铯催化二硫醚、二碲醚与端炔反应研究

氢氧化铯催化下, 以商业THF作溶剂, 在氮气氛中二芳基二硫醚与端炔室温反应, 立体选择地生成(Z)-1,2-二芳硫基烯. 在空气氛中反应, 得到(Z)-1,2-二芳硫基烯与炔硫醚的混合物. 二芳基二碲醚与端炔反应, 不论在氮气氛中或空气氛中, 都只产生炔碲醚. 但是在氮气氛中炔碲醚的收率仅为空气氛中反应的50%, 对上述反应机理进行了讨论.     

Selectfluor作用下二芳基二硫醚和醇的双亚磺酰化反应制备亚磺酸酯（英文）

报道了一种新型的由二芳基二硫醚和醇双亚磺酰化反应来制备亚磺酸酯的方法.在Selectfluor作为氧化剂的条件下,一分子二硫醚与两分子醇反应,能够顺利转化得到两分子亚磺酸酯产物.该反应无需金属催化剂,在简单温和的条件下即可进行,反应产率很高.反应底物适用性广,含有不同取代基的二硫醚和醇,包括天然的手性醇类化合物,均能很好地发生反应得到相应的产物.该方法实现了简单条件下通过醇的亚磺酰化反应高效地构建亚磺酸酯,为亚磺酸酯及其衍生物的合成提供了一条新的途径.     

二烯丙基硫醚化合物的合成

二烯丙基一硫醚（DS）,二烯丙基二硫醚（DDS）,二烯丙基三硫醚（DTS）和二烯丙基四硫醚（DTTS）等是大蒜提取液中的主要有效成分,具有十分广泛独特的生理药理活性。作者以甲酸、丙三醇为超始原料合成了这些化合物,烯丙基硫醚化合物总含量达83%,其中DDS,DTS含量分别达30%。产物均GC-MS鉴定确证。合成方法简单,原料易得,反应步骤少,实用性较强。     

Zn/AlCl3促进下二硫醚与α,β-不饱和化合物的共轭加成

二芳基二硫醚与锌粉在DMF 中110 ℃反应, 生成二硫醚与锌的复合物; 后者在无水AlCl₃存在下与丙烯酸酯、丙烯腈反应分别生成β-芳硫基丙酸酯和相应的腈, 产率48%～91%.     

烷基杂环芳基二硫醚类化合物的合成及抗癌活性研究

通过Bunte盐与杂环芳基硫醇反应,得到了一系列的烷基芳基二硫醚类化合物.得到的全部二硫醚类化合物对人结肠癌细胞HCT-116抑制活性进行了体外评价,发现所有化合物具有明显的体外抗肿瘤活性,其半抑制浓度IC50为4.8～17.7μg mL-1.     

醋酸酮催化二硫醚与四氢呋喃的氧化偶联反应

研究了醋酸酮催化二硫醚与四氢呋喃以氧化偶联反应构建C—S键。 结果表明,在醋酸酮(10%摩尔分数)、二硫醚(0.5 mmol)、四氢呋喃(2 mL)和双氧水(35%,2倍化学计量),反应温度120 ℃条件下,二硫醚与四氢呋喃能够顺利地发生氧化偶联反应,生成相应的C—S键化合物,合成硫醚类化合物产率中等到良好。 该反应以双氧水为氧化剂,具有环境友好等特性。     

聚二乙炴电子能带结构的研究

聚二乙炔(polydiacetylenes)具有平面的全共轭主链,并可被制备成宏观大小的单晶,因而是研究聚合物物理、化学性质的理想模型.它的物理、化学性质,特别是作为导电材料的导电机理与其价带及导带的结构密切相关.通过改变聚二乙炔的侧基可以对其主链几何结构及电子能带结构产生影响,进而改变其物理化学性质.可能是考     

钯催化条件下形成碳硫键合成多氯代二苯硫醚

以四三苯基膦钯为催化剂,碳酸铯为碱,氯代碘苯和氯代苯硫酚在甲苯中加热到112℃回流16 h,发生偶联反应形成C—S—C硫醚键,合成了23个多氯代二苯硫醚系列化合物,产物均经IR,1H NMR表征,并测定熔点.反应操作简单,收率良好,条件温和,是一种较好的合成多氯代二苯硫醚化合物的新方法.     

光诱导单电子转移反应合成硫杂、氮杂冠醚

合成了以邻苯二甲酰亚胺为电子受体,末端三甲基硅烷基醚链为电子给体的新的分子内给受电子体系N-(末端三甲基硅烷基硫杂醚链)邻苯二甲酰亚胺(1)和N-(末端三甲基硅烷基氮杂醚链)邻苯二甲酰亚胺(2).化合物1和2在甲醇中进行光反应,在光诱导下发生分子内单电子转移反应,以很高的产率和很高的区域选择性生成硫杂冠醚(3)和氮杂冠醚(4).化合物1~4的化学结构经核磁共振、质谱的验证.     

Thiol-Ene Cationic and Radical Reactions: Cyclization,Step-Growth,and Concurrent Polymerizations for Thioacetal and Thioether Units

Thiol-ene cationic and radical reactions were conducted for 1:1 addition between a thiol and vinyl ether, and also for cyclization and step-growth polymerization between a dithiol and divinyl ether. p-Toluenesulfonic acid (PTSA) induced a cationic thiol-ene reaction to generate a thioacetal in high yield, whereas 2,2′-azobisisobutyronitrile resulted in a radical thiol-ene reaction to give a thioether, also in high yield. The cationic and radical addition reactions between a dithiol and divinyl ether with oxyethylene units yielded amorphous poly(thioacetal)s and crystalline poly(thioether)s, respectively. Under high-dilution conditions, the cationic and radical reactions resulted in 16- and 18-membered cyclic thioacetal and thioether products, respectively. Furthermore, concurrent cationic and radical step-growth polymerizations were realized using PTSA under UV irradiation to produce polymers having both thioacetal and thioether linkages in the main chain.     

Thiol‐Ene Cationic and Radical Reactions: Cyclization,Step‐Growth,and Concurrent Polymerizations for Thioacetal and Thioether Units

Thiol‐ene cationic and radical reactions were conducted for 1:1 addition between a thiol and vinyl ether, and also for cyclization and step‐growth polymerization between a dithiol and divinyl ether. p‐Toluenesulfonic acid (PTSA) induced a cationic thiol‐ene reaction to generate a thioacetal in high yield, whereas 2,2′‐azobisisobutyronitrile resulted in a radical thiol‐ene reaction to give a thioether, also in high yield. The cationic and radical addition reactions between a dithiol and divinyl ether with oxyethylene units yielded amorphous poly(thioacetal)s and crystalline poly(thioether)s, respectively. Under high‐dilution conditions, the cationic and radical reactions resulted in 16‐ and 18‐membered cyclic thioacetal and thioether products, respectively. Furthermore, concurrent cationic and radical step‐growth polymerizations were realized using PTSA under UV irradiation to produce polymers having both thioacetal and thioether linkages in the main chain.     

Synthesis and mesomorphic properties of a series of dimers derived from thioether-terminated and cholesteryl

ABSTRACT

The synthesis and material properties of a series of new liquid crystalline compounds containing thioether and cholesteryl, these homologues with different alkyl chain lengths of 2–8, are reported. Thermal analysis shows that all oligomers have wide mesophase temperature ranges with high thermal stability. The oligomers were determined by differential scanning calorimetry (DSC) and polarising optical microscopy (POM). The molecule not only successfully exhibits strong optical properties and rainbow colours, but also the cholesteric helical pitch decreased with increasing temperature. The mesogenic incidence and tendency were found to be strongly dependent on the numbers of carbon in the flexible alkyl chain. Even members formed widely mesophase compared to odd members that showed narrower ones. The reflection wavelengths of 6S8Ch are almost across the entire visible region when they are heated, which offer tremendous potential for various optical applications. Also, it not only shows a lower transition temperature but also has a narrower cholesteric phase compared to analogues with alkoxy groups. These results not only provide practical design principles for the synthesis of new sulphur-containing LC materials with optical applications, also make a significant contribution to use as thermally sensitive liquid crystal devices requiring fast response.     

Controlling the conformation of arylamides: computational studies of intramolecular hydrogen bonds between amides and ethers or thioethers

The role of an ortho-alkylthioether group in controlling the conformation around the ring-N bonds of meta-connected arylamide oligomers is studied. Density functional theory (DFT) geometries of model compounds, including acetanilide, an ether acetanilide, and a thioether acetanilide, and their corresponding diamides, show that for either monoamide or diamide the alkyl side chain of the thioether should be perpendicular to the aryl plane, whereas for the ether monoamide, the alkyl side chain is in the aryl plane. DFT ring-N torsional potentials and constrained geometries of the model compounds demonstrate that carbonyl-S repulsion leads to a high torsional barrier and that intramolecular N-H...S and C-H...O hydrogen bonds and ring-amide conjugation lead to N-H having a preferred orientation in the benzene plane pointing towards S. The N-H bond lengthens and the ortho-ring C-H bond shortens in a regular pattern in the approach to the preferred orientation. Calculated IR frequencies for the N-H stretch show a clear red shift between model compounds without and with the thioether side chain.     

Synthesis of new thioxanthenes by organocatalytic intramolecular Friedel–Crafts reaction

An efficient organocatalytic route has been developed to synthesize novel substituted thioxanthenes (2a–2v) starting from diaryl thioether alcohols (1a–1v) using the intramolecular Friedel–Crafts reaction. The starting materials were obtained in two stages via a coupling reaction followed by the Grignard reaction. In this study, we tried for the first time to use some organic Brønsted acids as organocatalysts (3a–3h) in the intramolecular Friedel–Crafts cyclization reaction of thioether alcohols. The synthesis of original substituted thioxanthenes was achieved within 15?minutes by using N-triflylphosphoramide (3h) with quantitative yields in THF at room temperature.     

HPLC Analysis of the Isomeric Thioether Metabolites of Styrene Oxide

Abstract

An efficient separation of the isomeric thioether metabolites of styrene oxide was achieved under reversed-phase conditions. The column was eluted isocratically with 15% methanol in buffered solutions of phosphoric acid-tris-hydroxymethylaminomethane. The thioether conjugates were separated by class, and the order of elution was cysteine, cysteinylglycine, glutathione, and N-acetylcysteine. The effect of pH and buffer salt concentration on the HPLC separation was examined. Optimal conditions for a separation were either found at low pH (pH 3 or 4) or neutral pH, both at a high buffer salt concentration (75mM). The positional isomers and stereoisomers comprising each amino acid conjugate sample were separated into two peaks. The variations in k¹ and α observed with changes in pH were interpreted as reflecting the degree of interaction of the ionizable groups in the amino acid residue and the hydrophobic portion of the molecule. This interaction was found to be strongly influenced by the relative stereochemistry of the benzylic carbon center, thus allowing the separation of diastereoisomeric thioethers.     

俄罗斯直馏柴油中硫化物的分离富集与结构鉴定

采用选择性氧化剂和还原剂对俄罗斯直馏柴油中的硫醚类硫化物和噻吩类硫化物分别进行分离和富集,得到两者的浓缩液。运用质谱技术对分离出的硫化物结构进行鉴定。结果表明:氧化还原法是分离俄罗斯直馏柴油中硫化物的有效方法;硫醚类硫化物浓缩液中鉴定有烷基四氢噻吩和烷基四氢噻喃类化合物,四氢噻喃类硫化合物的烷基取代碳数在C4~C13范围;噻吩类硫化物浓缩液中有烷基侧链长度为C0~C9之间的苯并噻吩,烷基侧链长度为C0~C3之间的二苯并噻吩。     

Ion-Pair Liquid Chromatography of Alkylanilines

Abstract

The optimization of ion-pair liquid chromatography of structural isomers of carbon number two alkyl anilines has been studied.

The shorter alkyl cha in bonded silica gel demonstrated the stereo selectivity. the alkyl chain length of ion-pair reagent ruled the equilibration of ion-pair formation. the longer chain of ion-pair reagent formed hydrophobic ion-pair and the shorter chain could not form ion-pair, and ionized solute formed ion-pair with polar ion which was a component of eluent. Three ethylanilines and six xylidines mixture was separated on an octadecyl-bonded silica gel column using an eluent containing methanol/water mixture with sodium 1-dodecanesul-fonate.     

Electron Transfer from Thioethers

Abstract

Oxidation of thioethers is greatly facilitated by neighboring group participation by carboxylate, alcohol, and thioether moieties.     

Polymer Structure‐Guided Self‐Assisted Preparation of Poly(ester‐thioether)‐Based Hollow Porous Microspheres and Hierarchically Interconnected Microcages for Drug Release

Porous polymer microspheres (PPMs) have been widely applied in various biomedical fields. Herein, the self‐assisted preparation of poly(ester‐thioether)‐based porous microspheres and hierarchical microcages, whose pore sizes can be controlled by varying the polymer structures, is reported. Poly(ester‐thioether)s with alkyl side chains (carbon atom numbers were 2, 4, and 8) can generate hollow porous microspheres; the longer alkyl chain length, the larger pore size of microspheres. The allyl‐modified poly(ester‐thioether) (PHBDT‐g‐C₃) can form highly open, hierarchically interconnected microcages. A formation mechanism of these PPMs is proposed; the hydrophobic side chains‐mediated stabilization of oil droplets dictate the droplet aggregation and following solvent evaporation, which is the key to the formation of PPMs. The hierarchically interconnected microcages of PHBDT‐g‐C₃ are due to the partially crosslinking of polymers. Pore sizes of PPMs can be further tuned by a simple mixing strategy of poly(ester‐thioether)s with different pore‐forming abilities. The potential application of these PPMs as H₂O₂‐responsive vehicles for delivery of hydrophobic (Nile Red) and hydrophilic (doxorubicin hydrochloride) cargos is also investigated. The microspheres with larger pore sizes show faster in vitro drug release. The poly(ester‐thioether)‐based polymer microspheres can open a new avenue for the design of PPMs and provide a H₂O₂‐responsive drug delivery platform.