Diels-Alder Addition of Dicyclopentadiene with Cyclopentadiene in Polar Solvents

Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene（TCPD） that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity： benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows： benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.

Kinetics on Hydrogenation of Cyclopentadiene over Pd/γ-Al2O3 Catalyst

The macrokinetics of hydrogenation of cyclopentadiene was investigated over Pd/γ-Al2O3 catalyst.Experimental results showed that the relationship between the constituents and reaction time was in agreement with the characteristic of consecutive irreversible first-order reaction. Analysis on the reaction mechanism of selective hydrogenation of cyclopentadiene indicated that it is reasonable to express the hydrogenation rate of cyclopentadiene in the power law form. Parameters of the kinetic model were obtained by the Gauss-Newton method based on the experimental data. From the statistic test and residual error distribution the kinetic model was proved to be adequate.

Silver(I)-promoted Oxidation and Ring-enlargement Reactions of Unstrained Hydrocarbons, Polyphenyl-cyclopentadiene

A unique sliver(I)-promoted oxidation reaction of polyphenyl-cyclopentadiene is described, in which an oxygen is inserted into the cyclopentadiene-ring, forming a six-membered pyrylium cation.

Asymmetric Diels-Alder Reaction of 1-(S_R)-p-Tolylsulfinyl-3-penten-2-one with Cyclopentadiene Catalzed by a Chiral Titanium Reagent

Double asymmetric Diels-Alder reaction of 1(SR)-p-Tolylsulfinyl-3-penten-2-one with cyclopentadiene using a chiral titanium reagent was performed. The diastereoselectivity dependent on the size of aryl substituent involved in the chiral ligands was discussed Absolute configuration of the cycloadducts was conformed. Dramatic reversal of selectivity is observed.

MHEORETICAL STUDIES ON THE REACTION MECHANISMS OF CYCLOADDITION REACTIONS BETWEEN KETENE OR SUBSTITUTED KETENES AND CYCLOPENTADIENE

The cycloaddition reactions between ketene or substituted ketenes and cyelopentadiene have been studied theoretically by means of the semiempirical AMI method.Three different substituted ketenes have been selected and ten transition states,corresponding to different approach geometries have been located and characterized,The regioselectivity and stereoselectivity of the reactions are correctly predicted by the calculations and the reaction mechanisms are analyzed in terms of electronic and steric effects of the substitutents on the reacting ketene and cyc-lopentadiene.

Metal-free multicomponent polymerization of activated diyne,electrophilic styrene and isocyanide towards highly substituted and functional poly(cyclopentadiene)

The development of a facile and efficient polymerization to prepare cyclopentadiene-containing polymers is of vital importance and highly desired. In this work, a metal-free multicomponent polymerization of activated diyne, electrophilic styrene and isocyanide for the preparation of highly substituted poly(cyclopentadiene) was established. Soluble and thermally stable polymers with high molecular weights are obtained in high yields under mild conditions. By introducing the tetraphenylethene or triphenylamine moiety into polymer backbones, the resultant polymers show unique aggregation-induced emission(AIE)characteristics. Interestingly, AIE polymers can also be generated in situ from non-AIE monomers. Moreover, the prepared polymers can generate photopatterns to function as photoresists and can also serve as visualizing agents to selectively stain the lipid droplets in live cells. This efficient polymerization will open up enormous opportunities for preparing functional cyclopentadiene-containing polymers applicable in diverse areas.

降冰片烯制备工艺进展

环烯烃聚合物是一类性能优良的热塑性工程塑料,其单体降冰片烯的制备工艺复杂且存在工程安全问题,长期被少数企业垄断,价格昂贵。关于降冰片烯合成的报道多为专利,年代跨度大且缺乏系统性综述。本文围绕降冰片烯的制备过程,首先对双环戊二烯裂解制备环戊二烯工艺进行了总结,按照液相法、气相法进行分类和比较,分析了两种方法在反应温度、停留时间、反应设备、稀释剂和阻聚剂等方面的区别,探讨了两种方法的优劣势。之后总结了液相法、气相法或超临界法下加成反应制备降冰片烯的工艺特点,分析了不同制备方法在温度、压力、反应器形式、稀释剂等方面的区别和优劣势,为降冰片烯制备工艺的设计与优化提供了参考借鉴。最后,对多环降冰片烯衍生物的制备工艺进行了介绍。

Characterization and reactivity of γ-Al_2O_3 supported Pd–Ni bimetallic nanocatalysts for selective hydrogenation of cyclopentadiene

Several γ-Al2O3 supported Pd-Ni bimetallic nanocatalysts （Pd-Ni （x：y）[Al2O3; where x and y represent the mass ratio of Pd and Ni, respectively） were prepared by the impregnation method and used for selective hydrogenation of cyclopentadiene to cyclopentene. The Pd-NiJAl2O3 samples were confirmed to generate Pd-Ni bimetallic nanoparticles by X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and transmission electron microscopy （TEM）. The catalytic activity was assessed in view of the effects of different mass ratios of Pd and Ni, temperature, pressure, etc. Among all the samples, the Pd-Ni （1：1 ）/Al2O3 （PN-1：1 ） catalyst showed extremely high catalytic ability. The conversion of cyclopentadiene and selectivity for cyclopentene can be simultaneously more than 90%.

Synthesis of 2-Acyl-2H-1,2,3-diazaphospholes and Their Diels-Alder Reaction with Cyclopentadiene

H-1,2,3-Diazaphospholes 3a3h were prepared from various ketone acylhydrazones and phosphorus trichlo-ride in the presence of triethylamine. Compounds 3 underwent feasible hetero-Diels-Alder reactions with cyclopen-tadiene to afford the respective anellated [1,2,3]diazaphospholes 4a4d as well as 4a'4d' in moderate yields. The endo rule in the reaction was observed under kinetic control conditions.

裂解C_(9)馏分分离环戊二烯和甲基环戊二烯的技术进展

综述了近年来的C_(9)馏分分离环戊二烯和甲基环戊二烯的工艺,包括解聚反应-精馏、反应精馏、萃取精馏的研究应用进展。重点阐述了解聚反应-常压精馏、共沸精馏-解聚反应-常压精馏、减压精馏-解聚反应-常压精馏等几种工业上常用的解聚反应-精馏工艺的操作条件和技术优势,并指出阻聚剂的开发、工艺流程的优化、反应精馏技术的应用等方面是未来C_(9)馏分分离工艺的发展方向。

SYNTHESIS AND CHARACTERIZATION OF FLUORO-SUBSTITUTED β-ENAMINOKETONATO TITANIUM COMPLEXES AND THEIR CATALYTIC BEHAVIOR OF REGIOSELECTIVE ETHYLENE/CYCLOPENTADIENE COPOLYMERIZATION

The ethylene/cyclopentadiene （CPD） copolymerization behavior by using fluoro-substituted bis（fl- enaminoketonato） titanium complexes [FC6H4NC（CH3）CHCO（CF3）]2TiC12 （la-lc） has been investigated in detail. Upon utilizing MMAO as a cocatalyst, complexes la-lc exhibit high catalytic activities, affording the copolymers with high molecular weight and unimodal molecular weight distribution. Compared with non-substituted complex [C6HsNC（CH3）CHCO（CF3）]2TiC12 （1）, complexes la-lc can produce the copolymers with CPD incorporation adjusted in a wide range due to the enhancement of electrophilicity of metal center caused by introducing electron-withdrawing groups. Especially complex lc bearing fluorine at the para-position of N-aryl moiety provides the highest CPD incorporation, which is nearly two times （18.5 mol%） higher than the non-substituted complex 1 （8.9 mol%） under the same conditions. The highest CPD incorporation up to 24.6 mol% can be easily achieved using this complex. 1H-and 13C-NMR spectra demonstrate that these fluoro-substituted complexes possess regioselective nature with exclusive 1,2-insertion fashion, and alternating ethylene-CPD sequence can be detected at high CPD incorporation.

A New Synthetic Method of Highly Substituted Cyclopentadienes from α,β-Unsaturated Alkynones

Promoted by samarium diiodide in THF, the α,β-unsaturated alkynones were reduced to afford intermolecular reductive coupling products. The multiply substituted cyclopentadienes were prepared conveniently in good yields.

Synthesis of 5-vinyl-2-norbornene through Diels-Alder reaction of cyclopentadiene with 1,3-butadiene in supercritical carbon dioxide

An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was developed.The Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.

Synthesis, Characterization and Application of Benzyl-substituted Cyclopentadienyl lanthanide Complexes as Catalyst Precursors for the Syndiotactic Polymerization of Methyl Methacrylate

Yan-LongBALA, Muhammad D. XIE, Xiao-Min(HUANG, Ji-Ling*Laboratory of Organometallic Chemistry, East China University of Science and Technology, Shanghai 200237, China Benzyl-substituted cyclopentadienyl lanthanide complexes were synthesized and characterized by elemental analysis, MS and IR spectroscopy. The analytical data point out the formation of monomeric, unsolvated complexes. In conjunction with Al(Et)3 as co-catalyst, the title complexes are efficient catalysts for the syndiotactic polymeriza-tion of methyl methacrylate. For the complex (C6H5CH2C5H4)2YCl, under the optimum polymerization conditions (60 ℃, n(MMA)∶n(catalyst)∶n(co-catalyst)=1000∶1∶10), a predominantly syndiotactic (rr=66%) polymer of high molecular weight (Mh=105000) was obtained.

Synthesis,characterization and antioxidant activities of highly functionahzed cyclopentadienes catalyzed by ZnO-nanorod as economic and efficient heterogeneous nano catalyst

A three-component condensation was applied for the preparation of cyclopentadiene derivatives through the reaction of primary amines,alkyl propiolate and dialkyl acetylenedicarboxylate in the presence of catalytic amount of ZnO-nanorods（Zn-NR） under solvent-free conditions at 50 ℃.The method has proved to be synthetically green,simple,and effective with high atom economy and yield.The catalyst also revealed significant reusability.Moreover,the antioxidant activity and free radical scavenging capacity of the newly synthesized derivatives 4a,4b,4c,and 4d was screened using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl（DPPH） and ferric reducing antioxidant power（FRAP）assays and compared with hydroxytoluene（BHT） and tert-butylhydroquinone（TBHQ）.These compounds do not exhibit good DPPH radical scavenging,but they have a desirable FRAP.

Pd助剂用于Ni基环戊二烯加氢催化剂的研究

采用等体积浸渍法制备了以Al_(2)O_(3)-TiO_(2)复合氧化物为载体、Ni为主活性组分、Pd为助活性组分的负载型催化剂Pd-Ni/Al_(2)O_(3)-TiO_(2)。利用N2吸附-脱附、XRD、H_(2)-TPR、SEM等方法对催化剂进行表征,并在固定床微反实验装置上考察了Ni基催化剂助剂、Pd源、Pd负载量等对环戊二烯选择加氢制环戊烯反应性能的影响。实验结果表明,催化剂的Ni含量为17.5%(w)、Pd含量为0.3%(w)、比表面积为89 m^(2)/g、孔体积为0.35 mL/g、最可几孔径为12.6 nm时,Pd-Ni/Al_(2)O_(3)-TiO_(2)具有最佳反应性能;在反应温度40℃、反应压力0.40 MPa、氢/烃摩尔比1.2、新鲜进料体积空速1.5 h^(-1)的工艺条件下,环戊二烯转化率为95.4%,环戊烯选择性为94.5%,催化剂具有良好的加氢活性和稳定性。

环戊二烯选择加氢催化剂性能研究

采用固定床反应器,以Ni/Al 2 O 3为催化剂,研究了镍盐种类、载体焙烧温度、改性剂和钝化剂在环戊二烯选择加氢反应中对催化剂性能的影响。结果表明,X镍盐改性液作为活性组分,A物质作为钝化剂,经过T+200温度下焙烧的载体具有较好的催化活性,将载体进一步改性后,催化剂性能得到较大提升。将催化剂进行200 h长周期实验,结果表明催化剂具有较高的稳定性,环戊烯选择性保持在94%左右,环戊二烯转化率约在76%。

碳五反应精馏中共聚物的研究

对反应精馏的环戊二烯二聚过程中 ,伴随的异戊二烯、间戊二烯和环戊二烯反应产生的共二聚物进行了研究。温度是影响共二聚物生成量的主要因素 ,而异戊二烯含量的影响比间戊二烯含量大得多。同时根据试验结果提出了80℃的共二聚反应速率方程。

热二聚法分离C_5混合物中的环戊二烯

采用管式连续反应器及釜式间歇反应器对石油裂解 C5混合原料中的环戊二烯 (CPD)进行热二聚 ,生成双环戊二烯 (DCPD)后进行分离。深入研究了 CPD浓度、反应温度和反应时间以及 C6 含量等因素对反应的影响 。

反应精馏在裂解碳五分离中的应用

在分析现有萃取精馏碳五分离工艺流程的基础上,结合碳五馏分中双烯烃异戊二烯、间戊二烯和环戊二烯的反应动力学数据在AspenPlus中建立了反应精馏模型,结果表明反应精馏应用于碳五分离过程是可行的。