(Me_4N)SCF_3在三氟甲基硫化反应中的应用

本文综述了化合物(Me4N)SCF3在三氟甲基硫化反应中的应用。我们把三氟甲基硫化反应分为四个部分加以阐述,即:(i)卤代芳烃、硼酸化物和Ar-OTf的三氟甲基硫化;(ii)重氮化合物的三氟甲基硫化;(iii)炔基(苯基)碘磺酸酯的三氟甲基硫化;(iv)胺的三氟甲基硫化。     

氟代苯丙氨酸二芳基碘鎓盐前体的无酸合成

报道了一种无酸条件下合成二芳基碘鎓盐的方法。以4-碘-L-苯丙氨酸为原料,经酯化、氨基保护、无酸组合试剂氮-氟试剂/乙酰基三甲基硅烷反应、苯基三氟硼酸钾/三甲基硅三氟乙酸发生金属转移反应和在离子交换反应成功制得了目标产物4-(氮,氮-二叔丁氧羰基苯丙氨酸甲酯)苯基碘鎓六氟磷酸盐。该碘鎓盐与氟-18标记的氟离子反应可制备氟18-氟代苯丙氨酸,是一种潜在的正电子发射断层显像显像剂。     

2-碘-5-三氟甲基吡啶的合成

提出一种合成2-碘-5-三氟甲基吡啶的优化方法。以2-羟基-3=氯-5-三氟甲基吡啶为原料,经还原、取代两步制备2-碘-5-三氟甲基吡啶,并经过MS和1NNMR对目标化合物进行表征。该路线反应温和,操作简便。     

5-三氟甲基吲哚啉的合成

报道了 5-三氟甲基吲哚啉的一种合成新方法,即以对三氟甲基苯胺(1)为起始原料,引入甲磺酰基保护胺基,经芳环碘代反应生成N-(2-碘-4-三氟甲基苯基)甲磺酰胺(3),然后与三甲基乙炔基硅一锅法进行Sonogashira偶联和环化反应生成取代吲哚(4a)、(4b),在强碱作用下一锅法脱去Ms保护基和TMS生成吲哚(5),最后经氰基硼氢化钠还原成5-三氟甲基吲哚啉(TM),历经5步反应,总收率为40％,中间体和目标产物结构经1H NMR和MS确证.     

5-三氟甲基吲哚啉的合成

报道了 5-三氟甲基吲哚啉的一种合成新方法,即以对三氟甲基苯胺(1)为起始原料,引入甲磺酰基保护胺基,经芳环碘代反应生成N-(2-碘-4-三氟甲基苯基)甲磺酰胺(3),然后与三甲基乙炔基硅一锅法进行Sonogashira偶联和环化反应生成取代吲哚(4a)、(4b),在强碱作用下一锅法脱去Ms保护基和TMS生成吲哚(5),最后经氰基硼氢化钠还原成5-三氟甲基吲哚啉(TM),历经5步反应,总收率为40％,中间体和目标产物结构经1H NMR和MS确证.     

2-氟-4-三氟甲基苯乙腈的合成研究

以2-氟-4-三氟甲基溴苯为起始原料,先经甲酰化和醛基还原反应"一锅法"合成了2-氟-4-三氟甲基苄醇,继而以氯取代反应合成了2-氟-4-三氟甲基苄氯,最后经氰化反应合成了2-氟-4-三氟甲基苯乙腈。经优化后,4步反应总收率为88. 8%,气相色谱测得产品含量为99. 2%,是一个适合工业生产的工艺路线。     

间三氟甲基苯胺合成尼鲁米特

以间三氟甲基苯胺为原料,经重氮化碘代、硝基化、缩合反应合成尼鲁米特,考察了摩尔配比、硝酸浓度、催化剂的选择对各反应的影响。结果表明,优化的反应条件分别是：重氮化碘代反应,反应温度10℃,间三氟甲基苯胺与盐酸摩尔比为1∶3。5;硝化反应,反应温度10℃,硝酸的质量分数为90％,间碘三氟甲苯与硝酸的摩尔配比为1∶1。3;缩合反应以CuCl为催化剂。总收率约为35％。其结构经熔点、核磁共振、质谱验证无误。该工艺反应路线较短、条件温和、收率高、原料价廉易得,适合工业化生产。     

三氟甲基化剂-TNS-Tf试剂

分子上具有两个反应性 CF_8自由基的独特而有效的三氟甲基化剂-TNS-Tf(N-三氟甲基-N-亚硝基三氟甲基磺酰氨)已开发成功。TNS-Tf 是一种对活性芳烃、硫醇、二硫化物及尿苷衍生物有用的光、热三氟甲基化试剂。在室温下与悬浮于极性溶剂中的活性铜反应得到的 CF_8-Cu 能以很高的收率将碘代芳族化合物转变为 CF_8-芳族化合物。     

温室气体三氟甲烷资源化转化技术研究进展

主要综述了国内外有关副产三氟甲烷资源化转化技术的研究进展,包括直接作为三氟甲基化试剂合成含三氟甲基中间体、通过碘代反应制备三氟碘甲烷、高温裂解转化为四氟乙烯及六氟丙烯等含氟烯烃、与甲烷高温共裂解合成偏氟乙烯、通过氟氯交换反应将CHF_3转化为卤代烷烃。通过综合比较以上路线,发现CHF_3与CHCl_3进行氟氯交换制备CHClF_2和CHCl_2F反应是具有较好工业化应用前景的路线。     

喹喔啉类杀虫剂

本发明涉及有关新的喹喔啉及其盐类和以此类化合物作为杀虫剂的有效成份。以前的技术与课题在本发明化合物中,相似结构的先行技术有二氟甲基和溴氟代甲基取代的1,3,4-噁二唑及1,3,4-噻二唑衍生物,其在公开专利昭63-91389和公开专利昭63-250377中有介绍,而本发明化合物中如具有二氟甲基、溴代二氟甲基、碘代二氟甲基及三氟甲基的喹喔啉类则是以前未有报导的化合物。另外,本发明的喹喔啉类对害虫的防治活性也是本发明首先发现。     

The kinetics of ethylene hydrogenation catalyzed by metallic palladium

The activity of Pd(111) for ethylene hydrogenation is measured using a high-pressure reactor incorporated into an ultrahigh vacuum chamber for temperatures between 300 and 475 K, ethylene pressures between 50 and 300 Torr and hydrogen pressures from 45 to 600 Torr. The reaction rate is found to be rapid with turnover frequencies up to 400 reactions/site/s (where rates are referenced to the atom site density on the (111) face of palladium). The measured activation energy is 35 kJ/mol. A hydrogen reaction order of 1.02 was found at a reaction temperature of 300 K and an ethylene pressure of 100 Torr, where the hydrogen reaction order was found to depend on temperature. A negative reaction order of –0.22 was found in ethylene pressure at a reaction temperature of 320 K and a hydrogen pressure of 100 Torr. The reaction rates are in good agreement with values obtained on silica-supported palladium and with other work on palladium single crystals.     

Study of bulk chain-coupling reactions

Summary Block copolymers containing polyester and polyamide blocks have been prepared by the bulk reaction of the corresponding carboxy-terminated polymers with 2,2-bis(2-oxazoline) or 2,2-bis(5,6-dihydro-(4H)-1,3-oxazine) as chain-coupling reagents (CC). A two-step reaction has been used, involving (i) the reaction of polyamide with CC excess, and (ii) the addition of polyester, leading to a random distribution of blocks in the final block-copolymer. ¹H and ¹³C NMR studies show that the coupling reaction takes place in the expected way. The stability of the resulting polymers is higher than that of the starting oligomers, and DSC indicates a phase separation between polyester and polyamide phases.     

High temperature electrochemical heat pump using water gas shift reaction. Part I: Theoretical considerations

A new electrochemical heat pump using a combination of an electrolytic reaction at lower temperature to absorb low grade thermal energy and a thermochemical reaction at higher temperature to produce more efficient thermal energy is proposed. At a lower temperature, an endothermic reaction which cannot occur thermochemically proceeds with electrolysis. At a higher temperature, an exothermic reaction which is the reverse of the electrolysis reaction occurs thermochemically to produce high grade thermal energy. The water gas shift reaction, CO₂(g) + H₂(g) CO(g) + H₂O(g), in molten carbonate is one possible candidate for the new electrochemical heat pump and can lead to an increase in the temperature of the thermal energy from 1100 to 1200K. A heat pump system using the shift reaction is also considered theoretically.     

Comparative study of atmospheric and high pressure CO2 reforming of methane over Ni/MgO-AN catalyst

Catalytic activity of Ni/MgO-AN prepared from alcogel derived MgO was studied for the dry reforming of methane under atmospheric as well as high pressure (1.5 MPa). Different catalytic performances are observed in the atmospheric and high-pressure reactions; while the catalyst was highly active and extremely stable under atmospheric pressure it shows a self-stabilization process under high pressure. The self-stabilization process was characterized initially by a decrease in deactivation rate with increasing the reaction time-on-stream (TOS) up to ca. 12 h and then by a thereafter stabilization during the reaction. Characterizations of the coked catalyst with TPO, TEM, SEM, TPH and XRD techniques detected very little carbon deposits (ca. 0.2 wt% of the catalyst charge) on the used catalyst under atmospheric pressure. In contrast, large amount of whisker carbon deposit (ca. 100 wt% of the catalyst charge) were formed on the used catalyst under high pressure. In the high-pressure reaction, the activity decline during the initial stage was closely related to the amount of carbon deposits on the catalyst, which also became stabilized after the catalyst had served the reaction for ca. 12 h. The carbon deposits on the used catalyst in the high-pressure reaction contained two different components (-carbon and -carbon) while the carbon deposits in the atmospheric pressure reaction were in the form of -carbon. No notable sintering of metallic nickel was detected by XRD on the used catalyst in the reaction under atmospheric pressure whereas unavoidable sintering of metallic Ni particles happened within the very first hours of the high-pressure reaction.     

Synthesis of molybdenum(IV) sulphide: I. Reaction of hydrogen sulphide with molybdenum(vi) oxide in the presence of ammonium chloride

Molybdenum(VI) oxide reacted with hydrogen sulphide to give, either a mixture of molybdenum(IV) sulphide and molybdenum(IV) oxide, which is very difficult to separate, or, at higher temperatures molybdenum(IV) oxide only. In the presence of ammonium chloride, the reaction gave pure lubricant grade molybdenum(IV) sulphide. The reaction was studied with different process variables. Under optimum can be conditions 81.5% pure MoS₂ was obtained at 700°C. The overall reaction represented as: The densities of the products were measured. X-ray diffraction patterns of pure samples were taken.     

Marked Role of Carbon Monoxide in the Formation of Benzene During CH4-CO Reaction Over Rh/SiO2 Catalysts

Temperature-programmed desorption (He-TPD) and temperature-programmed reaction with hydrogen (H₂-TPR), carbon monoxide (CO-TPR) or methane (CH₄-TPR) were carried out to elucidate the benzene formation mechanism as well as the role of CO during CH₄-CO reaction over SiO₂-supported Rh catalysts. The steady-state surface for the CH₄-CO reaction was different from that of the CH₄ decomposition reaction. The existence of benzene-like adsorbed species as building blocks was demonstrated on the CH₄-CO reaction surface, while no such higher hydrocarbon adsorbed species was detected in the case of the CH₄ decomposition surface. On the contrary, in CO-TPR experiments various unsaturated hydrocarbons were released from the steady-state CH₄ decomposition surface, which was not the case from the CH₄-CO reaction surface. It is concluded that adsorbed CO may play an important role to enhance the C-C bond formation of carbonaceous species, which correlates deeply with the novel phenomenon of selective benzene formation in the CH₄-CO reaction.     

Preparation and characterization of thermo-sensitive microspheres with β-cyclodextrin groups

采用沉淀聚合机理,由一步法和两步法制备聚（N-异丙基丙烯酰胺-甲基丙烯酸缩水甘油酯） [P(NIPAM-co-GMA)]温敏性微球。其中一步法是同时加入所有反应物反应成微球,而两步法是先加NIPAM成微球,再加入GMA,最终均生成P(NIPAM-co-GMA)微球;再将改性的乙二胺代环糊精（EDA-β-CD）通过化学反应引入到P(NIPAM-co-GMA)微球结构中,制备得到聚（N-异丙基丙烯酰胺-甲基丙烯酸-2-羟丙基乙二胺基环糊精） [P(NIPAM-co-GMA/β-CD)]共聚高分子微球。分别用扫描电镜、红外光谱、控温激光粒度仪及光学显微镜对产物的形貌、结构和温敏特性进行了表征。结果表明,两种方法制备的微球均具有良好的单分散性和球形度,均能成功地固载β-环糊精（β-CD）基团,并且都有温度响应特性;但是,同一步法制备的微球相比,两步法制得的微球粒径明显较大,且微球固载有更多的β-CD。     

Cleavage of blocked isocyanates within amino-type resins: Influence of metal catalysis on reaction pathways in model systems

In the present work, a detailed account on the deblocking reactions of various blocked isocyanates in aqueous reaction media in the presence of amido- and hydroxyl-nucleophiles is given. Pyrazole- and oxime-blocked phenylisocyanate were reacted with monomethylolurea (MMU), dimethylolurea (DMU) and urea (U) in the presence of the catalysts (dibutyltin dilaurate DBTL 1, zirconium(IV)dionate 2, zinc(II)acetate 3 and manganese (III)dionate 4). Product formation was studied by kinetic analysis of either the hydrolytic or the additive reaction pathways, revealing strong differences in the reactions pathways of the used catalysts. Both zirconium(IV)dionate 2 and DBTL 1 lead to the formation of N-phenyl-N′-carbamidurea and N,N′-diphenylcarbamidurea 15 as the preferred products after reaction with urea as nucleophile, whereas zinc(II)acetate and manganese(III)dionate indicated a significantly stronger promotion of hydrolytic reaction pathways. Zirconium(IV)dionate 2 catalyst proved advantageous over DBTL 1 displaying a lower deblocking temperature.     

The CO-catalyzed conversion of H2S to H2 + sulfur part 2. The thermal decomposition of COS

The pyrolysis of COS has been studied over the temperature range 300 to 750°C using a variety of catalysts. The observed product distribution confirmed that two parallel reaction paths: 2 COS → 2 CO S₂ (2) and 2 COS → CO₂ + CS₂ (4) are involved in the decomposition. The decomposition yield increased with rising temperature, accompanied with a shift in selectivity. At temperatures lower than ～700°C the disproportionation reaction 4 was predominant, whereas at temperatures higher than 700°C, reaction 2 was favoured. In the high-temperature region (700 to 750°C) it was possible to achieve full suppression of reaction 4 with added CS₂. The pyrolysis of COS was also studied in a reactor packed with quartz chips without catalysts at high temperatures. Between 800 and 900°C, up to 99% conversion (with respect to the thermodynamic limit) could be achieved, with the almost complete absence of the disproportionation reaction 4. The results point to the commercial potential in the two-step reaction sequence: for the economic conversion of hydrogen sulfide to hydrogen and sulfur.     

响应面法优化β-Co(OH)2的合成

以硫酸钴、氢氧化钠为原料,氨水为络合剂,抗坏血酸为保护剂合成β-Co(OH)₂。实验研究了反应温度、氢氧化钠溶液浓度、络合剂与硫酸钴中Co²⁺的摩尔比和保护剂对产品收率的影响。采用三因素三水平的响应面分析法对工艺条件进行优化,得到了β-Co(OH)₂合成的最优工艺条件。实验结果表明：在反应温度为79 ℃、氢氧化钠溶液浓度为2.89 mol/L、络合剂与硫酸钴中Co²⁺的摩尔比为2.19等条件下,合成的β-Co(OH)₂最高收率为97.40%,同时通过X射线衍射对产物进行了结构表征。