Zeolite-Catalyzed Acetalization Ⅰ. Synthesis of Some Acetals and Ketals through Reaction of Carbonyl Compounds with Ethanediol

The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed

Acetalization of Poly(vinyl alcohol)/Soybean Protein Fibers

Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.

二氯肉桂酸的合成

以主要含有两种异构体的二氯苯甲醛为原料 ,经与乙二醇缩醛化反应并分馏得纯度较高的 2 ,3 二氯苯甲醛乙二醇缩醛及 2 ,5 二氧苯甲醛乙二醇缩醛 .使缩醛在酸作用下水解得到高纯度的两种二氯苯甲醛 .再经Perkin反应合成了相应的两种二氯肉桂酸 ,产物经结构分析表明为E构型的肉桂酸 .

Brφsted-acidic ionic liquids as efficient catalysts for the synthesis of polyoxymethylene dialkyl ethers

Acetalation of formaldehyde(HCHO)with dialkyl formal or aliphatic alcohol to prepare polyoxymethylene dialkyl ethers(RO(CH2O)nR,n≥1)catalyzed by Br?nsted‐acidic ionic liquids has been developed.The correlation between the structure and acidity activity of various ionic liquids was studied.Among the ionic liquids investigated,1‐(4‐sulfonic acid)butyl‐3‐methylimidazolium hydrogen sulfate([MIMBs]HSO4)exhibited the best catalytic performance in the reaction of diethoxymethane(DEM1)with trioxane.The influences of ionic liquid loading,molar ratio of DEM1to HCHO,reaction temperature,pressure,time,and reactant source on the catalytic reaction were explored using[MIMBs]HSO4as the catalyst.Under the optimal conditions of n([MIMBs]HSO4):n(DEM1):n(HCHO)=1:80:80,140°C,and4h,the conversion of HCHO and selectivity for DEM2?8were92.6%and95.1%,respectively.The[MIMBs]HSO4catalyst could be easily separated and reused.A feasible mechanism for the catalytic performance of[MIMBs]HSO4was proposed.

酸敏改性葡聚糖的制备和载药研究

以可生物降解的亲水性天然葡聚糖为反应底物,通过缩醛化反应制备两亲性的缩醛化葡聚糖,核磁共振、傅里叶红外等理化表征手段确定缩醛化葡聚糖成功地合成。利用乳化法制备出载药缩醛化葡聚糖纳米粒子,用动态光散射法测得粒径为501.9±15.8 nm。且具有优异的pH响应性,荧光分光光度计检测载药纳米粒子在pH=5.0的缓冲介质中阿霉素荧光药物的酸敏释放的荧光强度增强5倍,说明所设计的纳米载药系统具有酸敏释药功能。

Effects of metal and acidic sites on the reaction by-products of butyl acetate oxidation over palladium-based catalysts

Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption- desorption, X-ray fluorescence （XRF）, HE temperature programmed reduction （H2-TPR）, and NH3 temperature programmed desorption （NH3-TPD）. Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2- methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from iso4merization and protolysis reactions.

可见光介导喹喔啉-2(1H)-酮C3-H缩醛化反应

报道了一种可见光介导1,2,3,5-四(咔唑-9-基)-4,6-二氰基苯(4Cz IPN)催化喹喔啉-2(1H)-酮与乙缩醛酸的C3-H脱羧乙缩醛反应合成3-乙缩醛基喹喔啉-2(1H)-酮的方法.该反应采用空气为氧化剂,在室温下实现了一系列3-乙缩醛基喹喔啉-2(1H)-酮的绿色构建,反应具有能源清洁、条件温和、非金属参与和氧化剂绿色等优点.自由基捕捉实验和荧光猝灭实验表明,该反应涉及光诱导自由基反应历程.

反应萃取法分离1,3-丙二醇中缩醛反应的研究

研究了反应萃取法分离提取发酵液中1,3-丙二醇的重要反应—缩醛反应。考察了反应温度,反应时间,乙醛的添加量,以及催化剂对1,3-丙二醇转化率的影响。结果表明,通过乙醛与1,3丙二醇可以发生可逆缩醛反应生成2-甲基-1,3-二恶烷,得到最佳的反应条件为反应时间1h,反应温度为55℃,乙醛与1,3-丙二醇的物质的量比为6∶1,树脂催化剂为20g/L,1,3-丙二醇的转化率可以达到96%以上,可以满足1,3-丙二醇转化率的要求。首次采用D005-Ⅱ树脂作为缩醛反应的催化剂,考虑了树脂的重复使用情况。