炔烃亲电环化构建六元杂环的研究进展

采用有效和原子经济的路径合成杂环化合物是目前有机合成中研究的热点领域.综述了通过炔烃的亲电环化来构筑六元杂环及苯并六元杂环的研究进展.     

Synthesis of new polyesters containing phosphorus heterocycles and halogen

Two series of polyesters containing phenoxaphosphine rings and several halogens were synthesized by low-temperature solution polycondensation in the presence of triethylamine. One series, containing halogens only in the bisphenol moiety, was obtained from 2,8-dichloroformyl-10-phenylphenoxaphosphine-10-oxide and chlorinated bisphenol. In the second series, halogens belonged both to bisphenol and diacid dichlorides. For the last series, 2,8-dichloroformyl-10-(4-bromophenyl)phenoxaphosphine-10-oxide was prepared as a new monomer. All resulting polyesters were characterized by elemental analysis, reduced viscosity, IR and ¹H NMR spectroscopy, and thermogravimetric analysis. These polymers began to lose weight at about 400°C in air being seen as self-extinguishing ones.     

乙硼烷对碳杂键的还原

综述了乙硼烷试剂的制备方法及其作为还原试剂在对碳杂键还原中的应用,并介绍了乙硼烷在有机合成中的重要作用。     

含杂环多长碳链表面活性剂的合成及性能

以对苯二酚为原料,经MANNICH反应制得含杂环中间体1、2,进一步与长链卤代烷反应制得3种含杂环的多链表面活性剂34、、5。表面活性分析显示3、4可作为润湿剂、分散剂和消泡剂等。     

Solid-phase synthesis of sulfur containing heterocycles

Solid-phase organic synthesis by combinatorial techniques is a widely exploited area in the discovery of new pharmacologically active compounds and is a rapidly expanding area of synthetic organic chemistry. Because of many biological activities possessed by heterocycles, a large number of reports related to their solid-phase synthesis have appeared in recent decades. In this review article, I have described the importance of solid-phase synthetic strategies for the synthesis of sulfur atom containing heterocycles.     

Regioselective synthesis of indole-annulated sulfur heterocycles by tri-n-butyltin hydride-mediated aryl radical cyclization

2-[(2-Bromobenzyl)sulfonyl]indoles under Bu₃SnH-mediated aryl radical cyclization furnished exclusively the benzo[c]thiopyrano[2,3-b]indoles in 56–61% yields via 6-endo-trig cyclization whereas 2-[(2-bromobenzyl)sulfanyl]indole 3a gave only the β-scission product.     

杂原子分子筛Ni-ZSM-5的合成及其影响因素

采用水热法合成杂原子分子筛Ni-ZSM-5,通过改变原料配比、调变原料pH、改变晶化时间和晶化温度,考察不同条件对合成Ni-ZSM-5晶化产物的影响。XRD表征结果表明,在晶化温度160 ℃、晶化时间96 h、pH为9和n（SiO₂）∶n(TBAB)∶n(H₂O)=1.0∶0.2∶67条件下,通过简单的工艺流程可得到具有规则特征结构的杂原子分子筛Ni-ZSM-5。     

Synthesis and properties of triblock copolymers containing PDMS via AGET ATRP

The bromo-terminated macroinitiator was prepared by direct addition reaction of difunctional poly(dimethylsiloxane) (PDMS) containing methyl methacrylate end groups with hydrobromic acid in acetic acid under mild conditions, and well-defined triblock copolymers of poly(methyl methacrylate-b-dimethylsiloxane-b-methyl methacrylate) (MMA-b-DMS-b-MMA) were synthesized via activators generated by election transfer atom transfer radical polymerization (AGET ATRP). The gel permeation chromatography data obtained verified the polymerization and showed the well controlling of the reaction. FTIR and ¹H NMR measured the structure of the macroinitiator and copolymers. The contact angle measurement indicated that the water contact angles decreased gradually with the increasing of PMMA block content. The self-assembly behaviors of the triblock polymer were studied by transmission electron micrograph, scanning electron microscopy, and dynamic light scattering measurement. The results indicated that the polymers could self-assemble into various complex morphologies in different solvents and the morphologies depended on the properties of solvents. The possible molecular packing models for self-assembly behaviors of the ABA triblock polymers were proposed.     

Versatile electrochemically based preparation of unusual Grignard reagents containing electrophilic substituents

Upon electrochemical reduction of potassium perchlorate in dimethyl sulfoxide to potassium the strong dimsyl base (i.e. the conjugate base of dimethyl sulfoxide) is formed in the reaction of the alkali metal with the solvent. The electrolysis is performed in an undivided cell with a magnesium rod serving as sacrificial anode, thereby generating magnesium ions, which stabilize the generated dimsyl through ion-pair formation. In a second non-electrochemical step, Grignard type reagents R₂Mg are obtained simply by letting the magnesium salt of dimsyl base deprotonate weakly acidic substrates (pK_a < 26 in dimethyl sulfoxide) added to the solution. The advantage of generating these reagents through a deprotonation route rather than by reduction of halogen-substituted compounds as in the classical approach is that the substrates may contain electrophilic groups, such as halogen, carbonyl or cyano. The R₂Mg reagents react with electrophiles akin to ordinary Grignard reagents as illustrated by the preparation of several substituted benzylidenefluorenes in nucleophilic addition reactions. The electrochemical properties of the products were investigated and a reasonable linear correlation of the first reduction potentials with the Hammett substituent coefficient σ⁻ was found.     

Poly-sulfur-nitrogen heterocycles via sulfur chlorides and nitrogen reagents

The family of poly-sulfur-nitrogen heterocycles includes highly stable aromatic compounds that display physicochemical properties with relevance in the design of new materials, especially those relating to molecular conductors and magnets. The interesting characteristics found in many of these heterocycles have led to the development of modern synthetic methods that are the subject of this review. Heterocycles such as 1,2,3- and 1,2,5-thiadiazoles, 1,2,3- and 1,3,2-dithiazoles, 1,2,3,5-dithiadiazoles, thiatriazines, trithiadiazines, dithia(and trithia)diazepines, trithiatriazepines, di-thia(and trithia)tetrazozines, and fused systems are most commonly synthesized from tetrasulfur tetranitride and organic substrates (alkynes, diazomethanes), and from sulfenyl chlorides, sulfur or disulfur dichlorides and nitrogen containing reagents such as bis(trimethylsilyl)sulfurdiimide, trimethylsilyl azide, trisilylated amidines, N-imidoylamidines, hydrazones, oximes, and amines.     

Analysis and removal of heteroatom containing species in coal liquid distillate over NiMo catalysts

Heteroatom containing molecules in South Banko coal liquid (SBCL) distillate were identified with a gas chromatograph equipped with an atomic emission detector (GC-AED). Thiophenes and benzothiophenes were found to be the major sulfur compounds. Pyridines, anilines, and phenols were the major nitrogen and oxygen compounds, respectively. Reactivities of heteroatom containing species in hydrotreatment over conventional NiMoS/Al₂O₃, NiMoS/Al₂O₃–SiO₂ catalysts were very different according to their cyclic structure as well as the kind of heteroatom in the species. The sulfur species were completely desulfurized over the catalysts examined in the present study by 60 min at 360 °C under initial hydrogen pressure of 5 MPa. However, hydrodenitrogenation was more difficult than hydrodesulfurization even at 450 °C. Anilines were found the most refractory ones among the nitrogen species. Hydrodeoxygenation of SBCL was also difficult in the hydrotreatment conditions examined in the present study. Dibenzofuran was the most refractory molecule among the oxygen species. A two-stage reaction configuration at 340 and 360 °C improved HDN and HDO reactivities, although the conversions were still insufficient. Increasing the acidity of the support as well as the loading of the metals on the NiMoS/Al₂O₃ catalysts improved very much the heteroatom reduction to achieve complete removal of nitrogen by two-stage reaction configuration at 340–360 °C and oxygen at 360 °C, respectively. The addition of H₂S in the reaction atmosphere inhibited the HDN reaction but increased markedly the HDO conversion. The acidic support increased the activity in hydrotreatment through enhancing the hydrogenation activity, while H₂S maintained the catalyst in a sufficiently sulfided state.