溴代单甲基丙烯酸聚乙二醇酯的合成

甲基丙烯酸与聚乙二醇进行单酯化反应后,与三溴化磷进行溴化反应,合成了溴代单甲基丙烯酸聚乙二醇酯(B rPEG-MMA)。优化了溴化反应条件,并依靠红外光谱及化学分析手段,证实了目标产物的结构;并且测定了产物粘度在不同温度下的变化状况。     

4-单取代-1H-1,2,3-三氮唑的合成研究

以甲氧基聚乙二醇(mPEG)为起始原料通过磺酰化、叠氮化反应合成叠氮基甲氧基聚乙二醇(mPEG-N_3,2);在铜催化下和芳香炔、脂肪炔发生1,3-偶极环加成反应合成甲氧基聚乙二醇-1,2,3-三氮唑(mPEG-1,2,3-triazoles,3);再于酸性条件下脱除甲氧基聚乙二醇(mPEG)制备4-单取代-1H-1,2,3-三氮唑(4),其结构经过MS及~1H NMR、~(13)C NMR确证。     

基于Diels-Alder点击反应构建壳聚糖-O-聚乙二醇接枝共聚物

通过Diels-Alder(D-A)反应,合成了具有规整化学结构的接枝共聚物,壳聚糖-O-聚乙二醇(CS-O-PEG).D-A反应所需双烯体(呋喃环)通过糠基硫醇与端甲基丙烯酸酯聚乙二醇之间的巯基-丙烯酸酯(thio-acrylate)反应合成得到;马来酰亚胺基丙酸通过活泼酯法偶联到十二烷基硫酸钠-壳聚糖复合物(SCC)羟基上,从而获得亲双烯体.采用红外光谱(FTIR)和核磁共振(1H-NMR)表征了中间产物与最终产物的结构,并用原位核磁监测D-A反应及其逆反应过程.结果表明,聚乙二醇双烯体可在水介质中温和条件下定量接枝到壳聚糖羟基上,反应具有点击特征;同时,聚乙二醇与壳聚糖之间的连接键在高温下(90℃)可通过D-A逆反应而发生断裂.     

两亲性聚乙二醇桐油酸酯聚合物合成和性能研究

以桐油酸(ESA)和聚乙二醇(PEG)为原料,合成了一种新型的两亲性聚合物聚乙二醇-桐油酸酯(PEG-ESA)。通过红外光谱、质谱和核磁共振光谱法对产物进行表征。利用表面张力法和荧光探针法探究聚合物溶液相关性质,测定不同条件下两亲性聚合物胶束的zeta(ζ)电位和粒径。实验结果表明:利用表面张力法测得PEG-ESA临界胶束浓度(CMC)为1.1×10-5g/L;芘可以增溶于聚合物胶束中;在一定条件下聚合物的胶束可以稳定存在且粒径可达纳米级,为其用于药物缓释提供实验依据。     

新型表面活性剂聚乙二醇醚基双苯磺酸钠的合成及在催化水相三组分一锅法Mannich反应中的应用

报道了以聚乙二醇(PEG)为原料,经氯代,偶联制备新型表面活性剂聚乙二醇醚基双苯磺酸钠(DPSAS-PEG)的方法及其在催化水相中芳香胺、芳香醛和酮的三组分一锅法Mannich反应。该催化体系适应面较广,具有操作步骤简单,反应条件温和,产率较高的特点。     

壳聚糖与聚乙二醇交联水凝胶研究

研究对壳聚糖(CS)进行化学修饰得到了不同丙烯酰基取代度(1.03%,3.55%和5.21%)的丙烯酰化羟丙基壳聚糖(AHCS);通过自由基引发反应,AHCS与聚乙二醇二丙烯酸酯(PEGDA)交联得到壳聚糖(CS)与聚乙二醇(PEG)为主体的交联水凝胶。通过SEM观察其为通透性良好的多孔性支架材料。水凝胶的溶胶含量和溶胀度随丙烯酰基取代度的增加而降低,水凝胶中壳聚糖的降解速率也随丙烯酰基取代度的升高而降低。对于同一取代度的交联水凝胶,其在酸性和碱性条件下的溶胀度大于中性环境。细胞试验表明,壳聚糖与聚乙二醇交联水凝胶具有良好的生物相容性。     

固载聚乙二醇催化合成异黄樟油素

以聚乙二醇和固载聚乙二醇作为相转移催化剂, 在无溶剂条件下, 黄樟油素经催化异构合成异黄樟油素. 通过正交实验, 得到固载PEG-X (polyethylene glycol-X)催化最优工艺条件为: m(88.5%黄樟油)∶m(KOH)∶m(PEG-X)＝1∶0.2∶0.25, 反应温度90 ℃, 反应时间 5 h, 在此工艺条件下, 异黄樟油素得率为99.9%. 固载PEG-X催化剂循环使用10次后其催化活性未见下降. 结果显示, 固载聚乙二醇催化工艺具有操作简便、反应温度低、时间短、产率高以及对环境友好等优点. 用¹H NMR, GC-MS对异构黄樟油素结构进行了表征, 研究了固载聚乙二醇作为相转移催化剂合成异黄樟油素的反应机理.     

PEGDA/HEMA水凝胶等离子体表面改性的研究

采用紫外光聚合法合成了聚乙二醇双丙烯酸酯(PEGDA)/甲基丙烯酸-2-羟基乙酯(HEMA)复合凝胶,在不同的条件下进行等离子处理后,紫外光下进行表面接枝改性。在凝胶表面引入亲水性基团,改善材料的亲水性。研究了不同等离子体处理条件及辐射条件对丙烯酰胺(AAm)接枝率的影响。研究表明,丙烯酰胺接枝率随着等离子体处理时间的增加先增大后减小,随着紫外光照射时间、丙烯酰胺浓度的增大而增大。     

超临界二氧化碳中功能化聚乙二醇稳定的钯纳米粒子催化醇的选择氧化反应

 以超临界二氧化碳 (scCO2)/聚乙二醇 (PEG) 两相为反应介质, 双齿氮配体功能化聚乙二醇稳定的 Pd 纳米颗粒作为催化剂, 进行了醇的需氧氧化反应. 系统研究了催化剂制备条件和反应条件对苯甲醇需氧氧化反应的影响. 结果表明, 以氢气为还原剂制备的 Pd 纳米粒子的催化活性最高. 反应结束后, 可以利用 scCO2 直接进行原位萃取得到产物, 实现了催化剂与产物的有效分离和催化剂的循环使用. 反应中没有检测到钯的流失. 催化剂经过 5 次循环利用后转化率仍可达 98%.     

臭氧化合成聚乙二醇醛基衍生物

以甲氧基聚乙二醇为原料, 通过烯烃化得到甲氧基聚乙二醇烯烃,最后经臭氧化反应得到甲氧基聚乙二醇醛基衍生物。 通过核磁共振波谱仪(NMR)和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对产物的结构和性能进行了表征。 结果表明,该方法合成的产物纯度高,无副产物,甲氧基聚乙二醇乙醛和聚乙二醇丙醛的产率分别高达98%和99%,取代度分别为90.87%~99.91%和98%~100%。     

Direct Asymmetric Aldol Reactions Catalyzed by L-Proline/PEG/SiO2 Composite Catalyst

A simple and efficient composite catalyst of L-proline–polyethyleneglycol(PEG)–SiO₂ was developed for the asymmetric aldol reaction between acetone and p-nitrobenzaldehyde. With 10 mol% L-proline, the composite catalyst showed much better yield and enantioselectivity than the pristine L-proline over 1.5 h. Clear effects of the molecular weight of PEG and the properties of silica supports on the yield and enantioselectivity were observed, and the optimized catalyst can be reused for four cycles with stable performance.     

PEG型酸性温控离子液体中芳香酸和醇的酯化反应

报道了该催化体系在芳香酸和醇酯化反应中的应用. 研究发现, 该离子液体具有优良的催化性能, 产品易分离, 催化剂可循环使用且活性不降低, 催化剂不易流失, 实现了均相催化剂的高效回收和再利用.     

相转移催化合成对甲氧基肉桂酸-2-乙基己酯的研究

对甲氧基肉桂酸 2 乙基己酯是一种有效的ＵＶＢ防晒剂[1 ,2 ] ,一般采用Ｃｌａｉｓｅｎ Ｓｃｈｍｉｄｔ缩合反应制得[3] ,但由于催化剂ＫＯＨ处于水相 ,对反应物不能充分起到催化作用导致产率较低[4] 。我们利用乙二醇 (ＰＥＧ)为相转移催化剂合成立体专一的反式对甲氧基肉桂酸 2 乙基己酯 ,产率提高到 72 .5 %。合成路线如下 :1　实验部分1 .1　仪器与试剂ＢＩＯ ＲＡＰＦＴ45 0红外光谱仪 ,用液膜法测试 ;Ｂｒｕｒｅｒ ＡＭ 30 0超导核磁共振仪 (溶剂ＤＣ Ｃｌ3) ;ＭＡＴ/44Ｓ ,ＧＣ ＭＳ型色质联用谱仪 ;试剂均为分析纯 ,上海化学试剂…     

Effect of Organic Additives on the Performance of Nano-sized Ru-Zn Catalyst

A novel Ru‐Zn catalyst was prepared by coprecipitation. The catalyst was characterized by XRF, XRD and TEM. The effects of organic additives on the performance of the Ru‐Zn catalyst for benzene selective hydrogenation to cyclohexene were investigated. The results showed that the catalyst was composed of Ru and Zn in molar ratio of 33.8:1, and the most probable value of the Ru crystallite size in the catalyst was 5.1 nm. The modification of Ru with Zn and the small size effect were the main cause why the catalyst exhibited the high activity and the excellent cyclohexene selectivity. When PEG (polyethylene glycol) was used as an additive, the activity of the catalyst decreased, and the cyclohexene selectivity increased with the increase of the PEG molecular weight. With the addition of PEG‐20000, a cyclohexene selectivity of 78.9% at a benzene conversion of 68.7% and a maximum cyclohexene yield of 61.4% were obtained. With diethanolamine and triethanolamine as additives, cyclohexene yields were as high as 58.9% and 58.2%, respectively.     

肉桂酸环己酯的合成研究

肉桂酸环己酯为具有令人愉快的果香香气的无色粘稠液体 ,不溶于水 ,易溶于乙醇 ,常用于食用香精和日化香精的配料中 ,是典型的香料和食品添加剂[1,2 ] 。据报道 ,目前合成肉桂酸环己酯的方法有二 ,一是传统的硫酸催化酯化法 ,二是用路易斯酸ＦｅＣｌ3·6Ｈ2 Ｏ做催化剂来合成肉桂酸环己酯 ,两种方法虽有各自的优点 ,但它们的收率均不高 ,分别为 78.4%、73 .4% [3] 。近年来人们用相转移催化技术合成了许多酯类[4 ,5] ,受其启发 ,我们在催化剂浓硫酸中加入聚乙二醇 40 0作为混合催化剂来合成肉桂酸环己酯 ,获得了满意的结果 ,反应收率达 84.8…     

Design and Optimization of Ecofriendly One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles by Three-Component Condensation Using Response Surface Methodology

Phase-transfer-catalyzed, highly versatile, and high-yielding protocol for the synthesis of 2,4,5-triaryl-1H-imidazoles was developed through response surface methodology (RSM). The effects of different solvents, reaction paths, and phase-transfer catalysts (PTCs) in different concentrations were envisioned. Three independent variables (catalyst, catalyst loading, and solvent volume) identified by one-factor-at-a-time (OFAT) study were screened through full factorial design at two levels. The analysis of variance results suggested the significance of catalyst PEG400 and solvent glacial acetic acid at 5 h reaction. The optimum reaction conditions suggested by the RSM were the use of PEG400 (10.61 mol%) and glacial acetic acid (10.71 mL) for 5 h cycloocondensation. The experimental yield of 4,5-diphenyl-2-nitrophenyl-1H-imidazole (97%) was in agreement with predicted yield (97.5%).     

二乙二醇丙酸甲酯的合成与结构表征

采用二乙二醇和丙酸甲酯为主要原料,以钾为催化剂,在通N_2气保护的条件下合成二乙二醇丙酸甲酯,用离子排阻高效液相色谱法对合成的二乙二醇丙酸甲酯进行定量分析。最佳合成条件:二乙二醇与丙酸甲酯的物质的量比为1∶2,催化剂的质量为反应物二乙二醇质量的1.5%,于25℃条件下反应24 h,产物经硅胶柱分离、乙酸乙酯梯度洗脱,然后干燥,制得二乙二醇丙酸甲酯成品,收率为61.5%,纯度达99.5%。用FT-IR,~1H–NMR,GC–MS法对二乙二醇丙酸甲酯的分子结构进行了确证。     

Quaternary ammonium bromide functionalized polyethylene glycol: a highly efficient and recyclable catalyst for selective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions

A quaternary ammonium bromide covalently bound to polyethylene glycol (PEG, MW = 6000), i.e., PEG(6000-)(NBu(3)Br)2, was found to be an efficient and recyclable catalyst for the cycloaddition reaction of aziridines to CO(2) under mild conditions without utilization of additional organic solvents or cocatalysts. As a result, 5-aryl-2-oxazolidinone was obtained in high yield with excellent regioselectivity. The catalyst worked well for a wide variety of 1-alkyl-2-arylaziridines. Besides, the catalyst could be recovered by centrifugation and reused without significant loss of catalytic activity and selectivity.     

Introduction of PEGs on pore-wall of three-dimensionally ordered macroporous cross-linked polystyrene for catalyzation of α-butylation of phenylacetonitrile

Three-dimensionally ordered macroporous cross-linked polystyrenes (3DOM CLPS) attached polyethylene glycols (PEGs) with different molecular weights were prepared for use as a novel tri-phase transfer catalyst. The 3DOM catalysts were characterized by FTIR and SEM. The catalytic activity of functionalized 3DOM CLPS was evaluated using ??-butylation reaction of phenylacetonitrile in organic phase and potassium hydroxide aqueous solution in water phase as a model system. The effects of various factors on the phase transfer catalysis reaction of liquid-solid-liquid were investigated. Reusing performance of the catalyst was also examined. The results show that the 3DOM CLPS attached PEG400 is an effective and stable tri-phase catalyst for ??-butylation reaction. The reaction yield increases with the increasing of temperature and extension of time. After reusing for eight times, the PEG chains did not run off and the ordered structure was well preserved, and the yield of ??-butyl phenylacetonitrile was still above 90%.     

聚乙二醇稳定的RuB纳米粒子催化苯选择加氢为环己烯的性能研究

PEG稳定的RuB纳米粒子对苯选择加氢制备环己烯显示出良好的催化性能,在不添加硫酸锌的条件下,该体系催化的苯选择性加氢中,环己烯收率高达29%。这一体系的高催化性能是由于PEG稳定的RuB纳米粒子,使催化剂表面的亲水性增强,提高了环己烯的选择性。