PSA-PS在反-5-戊基-2-(4-氰基苯基)-1,3-二噁烷合成中的应用

以苯基磺酸官能化中孔硅基材料(PSA-PS)为催化剂,对氰基苯甲醛和2-戊基丙二醇为原料,催化合成了5-戊基-2-(4-氰基苯基)-1,3-二噁烷的顺、反混合物。并以同样的PSA-PS催化转型、重结晶后,得到反-5-戊基-2-(4-氰基苯基)-1,3-二噁烷纯品,收率83%。此外,在缩合反应中,对比对甲苯磺酸和氯化钙,使用PSA-PS催化可使反应时间缩短一半。PSA-PS在缩合、转型反应中可重复使用4次。

反式-5-甲氧基-3-苯乙烯基吲哚的合成

报道了新化合物反式-5-甲氧基-3-苯乙烯基吲哚的合成方法。氯化苄和三苯基膦在氯仿中回流得到氯化苄基三苯基(1),然后与5-甲氧基吲哚-3-甲醛通过Wittig反应生成目标产物,产物的结构经IR、1HNMR和MS得到确证,纯度99.3%。

顺(反)-2,4,7-三芳基5-氧代-4 H-5,6,7,8-四氢苯并吡喃衍生物的合成

在酸或碱性条件下 ,5 ,5 二甲基 1,3 环己二酮和 5 芳基 1,3 环己二酮与查尔酮首先进行Michael加成反应 ,进而环合为 7,7 二甲基 2 ,4 二芳基 5 氧代 4H 5 ,6,7,8 四氢苯并吡喃衍生物和含有两个手性原子的顺 和反 2 ,4,7 三芳基 5 氧代 4H 5 ,6,7,8 四氢苯并吡喃衍生物 .讨论了反应机理并且通过1HNMR光谱和NOE差谱确定其产物构型 .所合成新的多氢苯并吡喃衍生物的分子结构均经红外光谱、核磁共振光谱和元素分析予以证实 .

反式-5-(4-氯苯基)-4-甲基-2-氧代噻唑烷酮的合成

报道了一种合成噻螨酮关键中间体——反式-5-(4-氯苯基)-4-甲基-2-氧代噻唑烷酮的方法。以赤式-1-对氯苯基-2-氨基丙醇盐酸盐和二硫化碳为原料,在130℃下直接环合得到反式5-(4-氯苯基)-4-甲基-2-氧代噻唑烷酮,收率82%,色谱纯度99%;再经双氧水氧化得到噻螨酮关键中间体,收率84%,色谱纯度95%。该工艺流程经两步合成得到目标产物,简化了操作步骤,缩短了反应时间,避免了酸性废水的排放,符合绿色化工的要求。

反-4-(5'-丙基-四氢吡喃-2'-基)-环己基甲酸的合成

以反-4-(5'-丙基-四氢吡喃-2'-基)-苯甲酸(3PyPA)为原料,经催化加氢合成顺/反-4-(5'-丙基-四氢吡喃-2'-基)-环己基甲酸(3PyHA)混合物。加氢条件实验表明,以Ru/C为催化剂,以NaOH水溶液为反应介质,当反应温度为75～85℃,压力为3.5 MPa时反应效果最佳。加氢完粗品经高温异构化反应,甲苯乙醇混合溶剂重结晶得色谱纯度99.5%以上的反-3PyHA。

Reaction Characteristics of Asymmetric Synthesis of (2S,5S)-2,5-Hexanediol Catalyzed with Baker’s Yeast Number 6

Baker’s yeast number 6 was selected by screening. It showed good catalytic activity and enantioselec-tivity for asymmetric reduction of 2,5-hexanedione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spectrometry (GC-MS) revealed that the intermediate was (S)-5-hydroxyhexane-2-one. Reduction of 2,5-hexanedione proceeded in a two-step reaction. The hydroxyketone was initially formed, and this intermediate was further re-duced to the diol. Factors influencing the product yield and the enantiomeric excess of the reduction of 2,5-hexandione catalyzed by baker’s yeast number 6 were investigated. Higher concentration (≤100 mmol·L-1) of 2,5-hexandione did not influence 5-hydroxyhexane-2-one production, but 2,5-hexanediol production was inhibited by excess accumulation (>30 mmol·L-1) of intermediate. The optimal conditions were glucose as the co-substrate at an initial glucose concentration of 20 g·L-1, 34°C, pH 7.0 and cell concentration 60 g·L-1 (cell dry mass). Under the optimal condition and an initial substrate concentration of 30 mmol·L-1, the yield of 2,5-hexandiol was 78.7% and the enantiomeric excess of (2S,5S)-2,5-hexandiol was 94.4% for 24-h reduction.

Investigation of the coupled reaction of methyl acetate and n-hexane over HZSM-5

The coupled reaction of methyl acetate and n‐hexane was carried out over a HZSM‐5 catalyst.In addition to a thermal coupling effect,systematic variations in the product distribution were also observed in the coupled system.The bezene‐toluene‐xylene(BTX)selectivity was remarkably improved while the H2,CO,and CO2 selectivity decreased.Rapid deactivation of the catalyst was observed,caused by the extremely high reactivity of methyl acetate,which was alleviated after adding n‐hexane.These results indicated that a coupling effect exists in this system.A detailed pathway for the coupled system is suggested based on the analysis of the surface species,carbonaceous species deposited on the catalyst,as well as the product selectivity changes.The good match between the"hydrogen deficiency"of methyl acetate and the"hydrogen richness"of n‐hexane is consistent with the observed coupling effect.

Synergetic Effect of Y Zeolite and ZSM-5 Zeolite Ratios on Cracking, Oligomerization and Hydrogen Transfer Reactions

The objective of this study is to explore the optimum composition of Y and ZSM-5 zeolites to develop novel catalysts for obtaining lower gasoline olefins content and higher propylene yield. Five composite zeolite catalysts with varying Y zeolite/ZSM-5 zeolite ratios have been prepared in this work to investigate the synergy between the Y zeolite and ZSM-5 zeolite on the selectivity to protolytic cracking, β-scission, oligomerization, and hydrogen transfer reactions using a FCC naphtha feedstock at 480 ℃ in a confined fluidized bed reactor. Experimental results showed that the composite catalyst with a Y zeolite/ZSM-5 zeolite ratio of 1:4 had the highest protolytic cracking and β-scission ability, which was even higher than that of pure ZSM-5 catalyst. On the other hand, the catalyst with a Y zeolite/ZSM-5 zeolite ratio of 3:2 exhibited the strongest hydrogen transfer functionality while the pure Y zeolite based catalyst had the highest oligomerization ability. For all the catalysts tested, increasing conversion enhanced the selectivity to protolytic cracking and hydrogen transfer reactions but reduced the selectivity to β-scission reaction. However, no clear trend was identified for the selectivity to oligomerization when an increased conversion was experienced.

Changing the balance of the MTO reaction dual-cycle mechanism: Reactions over ZSM-5 with varying contact times

The methanol to olefins （MTO） reaction was performed over ZSM‐5 zeolite at 300℃ under various methanol weight hourly space velocity （WHSV） values. During these trials, the catalytic perfor‐mance was assessed, in addition to the formation and function of organic compounds retained in the zeolite. Analysis of reaction effluents and confined organics demonstrated a dual‐cycle reaction mechanism when employing ZSM‐5. The extent of the hydrogen transfer reaction, a secondary reac‐tion in the MTO process, varied as the catalyst‐methanol contact time was changed. In addition, 12C/13C‐methanol switch experiments indicated a relationship between the dual‐cycle mechanism and the extent of the hydrogen transfer reaction. Reactions employing a low methanol WHSV in conjunction with a long contact time favored the hydrogen transfer reaction to give alkene products and promoted the generation and accumulation of retained organic species, such as aromatics and methylcyclopentadienes, which enhance the aromatic cycle. When using higher WHSV values, the reduced contact times lessened the extent of the hydrogen transfer reaction and limited the genera‐tion of methylcyclopentadienes and aromatic species. This suppressed the aromatic cycle, such that the alkene cycle became the dominant route during the MTO reaction.

Ethylbenzene disproportionation and p-xylene selectivity enhancement in xylene isomerization using high crystallinity desilicated H-ZSM-5

Desilication accompanied with minimum loss of crystallinity effect of a high alumina ZSM-5 zeolite on the isomerization reaction of ethylbenzene/xylene mixtures has been considered.Desilication was assessed through XRF,XRD,FTIR,TEM,nitrogen adsorption/desorption,NH_3-TPD,^(29)Si and^(27)Al MAS NMR analytical techniques.Desilication was accompanied with the creation of super acid sites.There exists a limit(Si/Al molar ratio of9.67)for keeping high crystallinity and obtaining improved catalytic performance.Desilication promotes ethylbenzene conversion by disproportionation and trans-alkylation reactions while the same reactions are limited for the xylene isomers.The p-xylene approach to equilibrium improves by more than 7% at 400℃ and a WHSV of 2 h^(-1)for the optimum sample with respect to the parent zeolite.At the same conditions,the optimum sample exhibits the maximum ethylbenzene conversion of 89%,i.e.more than 40%w.r.t.of the parent zeolite.However,the xylene yield decreases only 3%.

Synthesis of MgO-Al_2O_3/ZSM-5 by Solid State Reaction for Propane Dehydrogenation

Solid-state grinding is a simple and effective method to introduce guest species into the channels of microporous materials through filling.The structure and the surface acidity of the materials were obtained from BET isotherms and NH3-TPD,respectively.XRD,UV-vis,UV diffuse-reflectance,and TEM were used to characterize the phases,and the morphology,respectively.The clustered layers of MgO-Al2O3phases were formed in the internal pore surface and were highly dispersed inside the channels of the ZSM-5 host.So the volume of MgO-Al2O3/ZSM-5 composite was larger than the ZSM-5 zeolite itself and some mesoporous channels appeared when Mg/Al species entered the channels.Meanwhile,new acid sites emerged in MgO-Al2O3/ZSM-5 composite and the acid amount of the sample changed.The improved Pt dispersion and the increased acid content would cause the increase of propane conversion and the modification of selectivity during the reaction.

Catalytic Pyrolysis of Biodiesel Surrogate over HZSM-5 Zeolite Catalyst

To obtain insight into the catalytic reaction mechanism of biodiesels over ZSM-5 zeolites,the pyrolysis and catalytic pyrolysis of methyl butanoate,a biodiesel surrogate,with H-type ZSM-5(HZSM-5)were performed in a flow rereac tor under atmospheric pressure.The pyrolysis products were identified and quantified using gas chroma to graphy-mass spec trome try(GC-MS).Kine tic modelling and experimental results revealed that H-atom abstraction in the gas phase was the primary pathway for methyl butanoate decomposition during pyrolysis,but dissociating to ketene and methanol over HZSM-5 was the primary pathway for methyl butanoate consumption during catalytic pyrolysis.The initial decomposition temperature of methyl butanoate was reduced by approximately 300 K over HZSM-5 compared to that for the uncatalyzed reaction.In addition,the apparent activation energies of methyl butanoate under catalytic pyrolysis and homogeneous pyrolysis conditions were obtained using the Arrhenius equation.The significantly reduced apparent activation energy confirmed the catalytic performance of HZSM-5 for methyl but anoa te pyrolysis.The act iva tion t empera ture may also affec t some catalytic proper ties of HZSM-5.Overall,this study can be used to guide subsequent catalytic combustion for practical biodiesel fuels.

Secondary Crystallization of Na_2CO_3-Modified HZSM-5 Zeolites with Tetrapropylammonium Hydroxide and Their Catalytic Performance in Thiophene Alkylation Reaction

The Na2CO3-modified HZSM-5 zeolites were further treated by tetrapropylammonium hydroxide(TPAOH) solution. The effect of TPAOH concentration on the secondary crystallization process was investigated. The resulting samples were characterized by a complementary combination of X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, X-ray fluorescence spectroscopy, XPS, 27 Al and 29 Si magic-angle spinning nuclear magnetic resonance spectroscopy, BET and temperature-programmed desorption techniques. The results showed that the secondary crystallization of the HZSM-5 zeolite could result in migration of non-framework species from the internal channels to the zeolite surface and their transformation into framework species. The catalytic activity of these modified samples for thiophene alkylation was evaluated. Both the activity and stability of the catalysts were improved after secondary crystallization.

A stage-specific protein factor binding to a CACCC motif in both human β-globin gene promoter and 5'-HS2region

The DNasel hypersensitive site 2 (HS2) of human β-globin locus control region (LCR) is required fOr the high level expression of human d-globin genes. In the present study, a stage-specific protein factor (LPF-β) was identified in the nuclear extract prepared from mouse fetal liver at d 18 of gestation, which could bind to the HS2 region of humanβ-globin LCRt We also found that the shift band of LPF-βfactor could be competed by humanβ-globin promoter. However, it couldn’t be competed by human E-globin promoter or by human Aβ-globin promoter. Furthermore, our data demonstrated that the binding-sequence of LPF-d factor is 5’CACACCCTA 3’,which is located at the HS2 region ofβ-LCR (from -10845 to -10853 bp) and humanβ-globin promoter (from -92 to -84 bp). We speculated that these regions containing the CACCC box in both the humallβ-globin promoter and HS2 might function as stage selector elements in the regulation of humanβd-globin switching and the LPF-βfactor might be a stage-specific protein factor involved in the regulation of humanβ-globin gene expression.

Proteins binding to the 5'-flanking regulatory elements of the human β-globin gene

The binding of nuclear proteins prepared from mouse erythroid tissue in different developmental stages to the 5'-flanking regulatory elements of human β-globin gene, two negative control regions(NCR1,-610 to -490 bp;NCR2, -338 to-233bp), was identified.Two stage specific protein factors corresponding to embryonic and fetal stages were found to be capable of binding to NCR2.These data provided evidence that the cis acting elements of the 5'-flanking region might be involved in the developmental control of β-globin gene and NCR2 might be responsible in part for the silence of β-globin gene in the embryonic and fetal stages.

Construction of an operando dual-beam fourier transform infrared spectrometer and its application in the observation of isobutene reactions over nano-sized HZSM-5 zeolite

An operando dual‐beam Fourier transform infrared (DB‐FTIR) spectrometer was successfully developed using a facile method. The DB‐FTIR spectrometer is suitable for the real‐time study of the dynamic surface processes involved in gas/solid heterogeneous catalysis under real reaction conditionsbecause it can simultaneously collect reference and sample spectra. The influence of gas‐phasemolecular vibration and heat irradiation at real reaction temperatures can therefore be eliminated.The DB‐FTIR spectrometer was successfully used to follow the transformation of isobutene over nano‐sized HZSM‐5 zeolite under real reaction conditions.

具有铁氧化和好氧反硝化功能的Achromobacter denitrificans strain 2-5对序批式反应器生物脱氮性能及群落结构的影响

对1株具有铁氧化和好氧反硝化功能的反硝化无色杆菌2-5(Achromobacter denitrificans strain 2-5)强化SBR反应器脱氮性能与细菌群落结构的影响进行研究。结果表明:在SBR反应器中,添加Fe^(0)和Achromobacter denitrificans strain 2-5能提高SBR反应器对NH_(4)^(+)-N和TN的去除效果,与普通SBR反应器相比,NH_(4)^(+)-N和TN的平均去除率分别提高了4.13%、15.73%。通过高通量测序分析,发现各反应器微生物群落结构组成存在差异。从门水平来看,变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)为优势菌门。添加Fe^(0)和Achromobacter denitrificans strain 2-5使反应器中具有好氧反硝化功能的细菌多样性增加,强化了SBR反应器的脱氮效果,研究结果为Fe^(0)促进好氧反硝化菌生长,强化污水脱氮提供了依据,有利于好氧反硝化菌的实际应用。

白藜芦醇类似物的合成

3,5-二甲氧基苄溴(4)与NaCN反应生成3,5-二甲氧基苄腈(5),5经水解得到3,5-二甲氧基苯乙酸(6).5与苯甲醛或取代苯甲醛发生Knoevenagel反应生成化合物2a～2d,为Z式构型.6与苯甲醛或取代苯甲醛发生Perkin反应得到化合物3a～3c,为E式构型.2a～2d和3a～3c均为白藜芦醇类似物.给出了各步反应产物的IR,1HNMR,13CNMR和MS数据,讨论了影响反应的因素,并给出了化合物2a～2d和3a～3c对乳腺癌细胞MCF-7、肺癌细胞H446、乳腺癌细胞231的体外生理活性和对正常肝细胞L02体外毒性的半致死浓度.

大叶紫珠中得到的一个新苯丙素类衍生物（英文）

采用硅胶、ODS和葡聚糖凝胶LH-20柱层析方法,从大叶紫珠(马鞭草科)70%乙醇提取物的乙酸乙酯萃取部位得到一个新的苯丙素类衍生物。采用包括电喷雾离子化高分辨质谱和一维、二维核磁共振等多种光谱学手段鉴定该化合物结构为2-甲氧基对苯二酚-4-O-[(5-O-反式-咖啡酰)-β-D-呋喃芹菜糖]-(1→2)-β-D-吡喃葡萄糖苷。

Physicochemical Properties and Catalytic Performance of a Novel Aluminosilicate Composite Zeolite for Hydrocarbon Cracking Reaction

A novel micro-micro/mesoporous aluminosilicate ZSM-5-Y/MCM-41 composite molecular sieve with a MCM-41 type structure was synthesized through a novel process of the self-assembly of CTAB surfactant micellae with silica-alumina source originated from alkaline treatment of ZSM-5 zeolite. The physical properties of the ZSM-5- Y/MCM-41 composite molecular sieve were characterized by XRD, Py-FTIR and N2 adsorption-desorption techniques. Different kinds of molecular sieves including ZSM-5, Y zeolite, AI-MCM-41, ZSM-5/MCM-41 and ZSM-5-Y/MCM- 41 as cracking catalysts were investigated, using 1,3,5-triisopropylbenzene （1,3,5-TIPB） as the probe molecule. Catalytic tests showed that the ZSM-5-Y/MCM-41 composite molecular sieve exhibited higher catalytic activity compared with the microporous ZSM-5 zeolite, Y zeolite, mesoporous A1-MCM-41 molecular sieve and ZSM-5/MCM-41 composite molecular sieve under the same conditions. The remarkable catalytic activity was mainly attributed to the presence of the hierarchical pore structure and proper acidity in the ZSM-5-Y/MCM-41 composite catalyst. Meanwhile, a carbcnium ion mechanism was put forward for the cracking of 1,3,5-TIPB.