Ti-MWW催化氯丙烯环氧化固定床工艺研究

以Ti-MWW分子筛为催化剂,H2O2为氧化剂,研究了氯丙烯环氧化制环氧氯丙烷固定床工艺过程的反应规律.结果表明,H2O2的空速对该反应过程起着非常重要的作用.优化的反应参数为:以乙腈为溶剂,氯丙烯/H2O2摩尔比为5,反应温度为333K,H2O2空速为0.44h-1.在该条件下氯丙烯转化率、环氧氯丙烷选择性、H2O2转化率及有效利用率分别达到19.0%,99.9%,98.0%和97.0%。     

无溶剂条件下反应控制相转移催化氯丙烯氧化制环氧氯丙烷

系统地研究了无溶剂条件下,H2O2为氧源,反应控制相转移催化剂[(C16H33(70%)+C18H37(30%))N(CH3)3]3[PW4O16]催化氯丙烯环氧化制环氧氯丙烷反应.结果表明,在氯丙烯/H2O2/催化剂(摩尔比)=400∶100∶1条件下,50～55℃反应3 h,环氧氯丙烷的收率为85～87%.在NaH2PO4存在下,催化剂循环使用5次,活性无明显降低,新鲜催化剂和回收催化剂的31P MAS NMR谱分析结果表明NaH2PO4对催化剂结构和组成具有稳定作用.     

强极性溶剂作用下肉桂酸缩水甘油酯的合成研究

以肉桂酸钠和环氧氯丙烷为原料,在不同的溶剂中合成了肉桂酸缩水甘油酯,考察了溶剂种类、溶剂用量、反应温度、反应时间和催化剂等对反应产率的影响,优化了反应条件.研究结果表明,溶剂的极性对反应结果影响显著,无催化剂条件下,以二甲基亚砜(DMSO)为溶剂,肉桂酸钠与环氧氯丙烷物质的量之比为1∶10,反应温度120℃,反应时间10 h,肉桂酸钠缩水甘油酯的产率可达81.5%.     

磷钨杂多酸盐／SiO2可逆负载催化剂催化氯丙烯环氧化制环氧氯丙烷

通过原位负载法合成了一种新的具有可逆负载特性的磷钨杂多酸盐/SiO2催化剂,并应用于氯丙烯环氧化反应.在反应温度65℃的条件下,系统研究了原位负载过程中反应时间、调节剂Na2HPO4用量、烯烃/H2O2摩尔比和硅烷化硅胶粒度大小等因素对环氧化反应的影响,并考察了催化剂的循环使用效果.实验结果表明,在适宜的反应条件下,初始反应环氧氯丙烷的产率达86·5%,催化剂循环使用3次,催化活性基本保持不变.     

Sc(Ⅲ)催化硫醇对邻亚甲基苯醌的亲核加成反应合成邻羟基苄硫醚衍生物

以2-[羟基(苯基)甲基]苯酚类化合物和简单的硫醇为原料, 1,2-二氯乙烷为溶剂, 在Sc(Ⅲ)促进下原位生成邻亚甲基苯醌, 并发生亲核加成反应构建邻羟基苄硫醚. 该反应在50 ℃下搅拌2 h即可完成, 目标产物产率82%95%. 反应可放大至克级规模.     

α－烯丙基甘油醚的合成新方法

在路易斯酸催化下，烯丙醇和环氧氯丙烷经加成、环化和水解后得到标题化合物，该法比文献报道的甘油－氯丙烯法产率提高约１０％。     

用离子液助溶剂制备对甲苯磺酰氯

分别以4种离子液为新型助溶剂,以对甲苯磺酸（TsOH）和氯磺酸（ClSO3H）为反应原料,以二氯乙烷为溶剂,制备了对甲苯磺酰氯（TsCl）。着重研究了离子液对TsOH在二氯乙烷和硫酸中的溶解度比s及TsCl产率的影响。研究结果表明,离子液的加入可显著提高TsOH的s值,进而提高TsCl的产率。在4种离子液中,[BuPy]BF4的效果最佳。当[BuPy]BF4的用量为2（wt）%时,s值和TsCl的产率分别达12.5和87.36%。同时,考察了反应物配比、反应温度及反应时间对TsCl产率的影响。通过正交实验得到较优的反应条件为：n(ClSO3H):n(TsOH)为1.5:1,反应温度为25℃,反应时间为2h。     

手性环氧氯丙烷的CPO酶催化不对称合成

基于氯过氧化物酶(CPO)对有机底物的手性识别,以CPO催化、叔丁基过氧化氢(TBHP)氧化3-氯丙烯合成手性(R)-环氧氯丙烷,并引入多羟基化合物为添加剂提高了目标产物的产率及对映选择性.反应主要受体系的pH值以及CPO用量等因素控制.UV-vis及CD光谱分析表明,反应体系中引入多羟基化合物(甘油、PEG400、PEG600)时,CPO的血红素辅基暴露程度增加,底物容易接近活性中心,同时CPO的α-螺旋结构得以加强,从而有效提高了产物收率.CPO对底物的手性识别主要基于底物与酶催化中间体([Fe(IV)=O·]+)形成的复合物对酶的稳定性的影响.通过反应条件优化,(R)-环氧氯丙烷产率可达67.3%,对映选择性(ee)97.5%.     

用离子液体为助溶剂制备对甲苯磺酰氯

分别以4种离子液体为新型助溶剂,以对甲苯磺酸(Ts OH)和氯磺酸(Cl SO3H)为反应原料,以二氯乙烷为溶剂,制备了对甲苯磺酰氯(Ts Cl)。着重研究了离子液体对Ts OH在二氯乙烷和硫酸中的溶解度比s及Ts Cl产率的影响。研究结果表明,离子液体的加入可显著提高Ts OH的s值,进而提高Ts Cl的产率。在4种离子液体中,[Bu Py]BF4的效果最佳。当[Bu Py]BF4的用量为2(wt)%时,s值和Ts Cl的产率分别达12.5和87.36%。同时,考察了反应物配比、反应温度及反应时间对Ts Cl产率的影响。通过正交实验得到较优的反应条件为:n(Cl SO3H)∶n(Ts OH)为1.5∶1,反应温度为25℃,反应时间为2h。     

四正丁基过硫酸铵氧化裂解2，4-二硝基苯腙衍生物的反应研究

四正丁基过硫酸铵在1,2二氯乙烷溶剂中可高产率地使醛和酮的2,4-二硝基苯腙衍生物氧化裂解成相应的羰基化合物,其分子中碳碳双键,氰基,酯基和缩醛基等基团均不受影响。同时探讨了可能的反应机理和反应溶剂对氧化裂解反应的影响。     

An environmentally benign route for epichlorohydrin from allyl chloride epoxidation catalyzed by heteropolyphosphatotungstate

In the absence of organic solvent, allyl chloride was epoxidized with aqueous hydrogen peroxide catalyzed by a heteropolyphosphatotungstate catalyst with very good activity and recycling activity. Under optimized conditions, an epichlorohydrin yield of 88.7% was achieved in the first run; after two recycles, the epichlorohydrin yield remained still above 85.0%. Various factors affecting the catalytic reaction were investigated systematically. The reaction rate of hydrogen peroxide in the epoxidation of allyl chloride is zero order with respect to hydrogen peroxide. The activation energy is 52.27 kJ/mol.     

The study of epoxidation of allyl chloride in methanol in the presence of extruded titanium containing silicalite

The liquid-phase epoxidation of allyl chloride in methanol with aqueous solution of hydrogen peroxide was conducted in the presence of extruded titanium containing silicalite and the physico-chemical features of the process were investigated. The effect of the amount of solvent, the initial ratio of the allyl chloride to hydrogen peroxide and the temperature of the process on the yield of the target product (epichlorohydrin) and by-products (3-chloro-1,2-propanediol and 3-chloro-1-methoxypropanol-2) was studied. Based on the obtained results, the optimum conditions of synthesis of epichlorohydrin for a laboratory scale continuous setup were recommended.     

Ti-MWW催化烯丙基氯环氧化高效合成环氧氯丙烷

 研究了具有MWW结构的新一代钛硅分子筛Ti-MWW催化剂对烯丙基氯液相环氧化高效合成环氧氯丙烷的催化性能. 结果表明, Ti-MWW的催化活性以及产物选择性均优于传统的钛硅分子筛TS-1. 对于Ti-MWW,合适的溶剂为非质子性溶剂丙酮和乙腈,在该溶剂中环氧化物不易发生溶剂化开环反应; 而对于TS-1,合适的溶剂是质子性溶剂甲醇,但甲醇可导致醇醚副产物的生成. 在Ti-MWW催化剂上烯丙基氯的转化率和环氧氯丙烷的选择性都能达到99%以上.     

Study of alkene epoxidation in the presence of extruded silicalite titanium

Main features of liquid-phase epoxidation of propylene, allyl chloride, and allyl alcohol by aqueous solution of hydrogen peroxide in the presence of extruded titanium silicalite in methanol medium have been investigated. The effects of the solvent, the initial ratio of the organic substrate: hydrogen peroxide, and temperature on the yield of main products and by-products were elucidated. Based on the obtained features the conditions for the synthesis of propylene oxide, epichlorohydrin, and glycidol in a laboratory continuous set-up were established.     

Epoxidation of allyl chloride with H_2O_2 on Ti-ZSM-5 prepared by the isomorphous substitution

The epoxidation of allyl chloride with H2O2 on Ti-ZSM-5 prepared by isomorphous substitution of HZSM-5 with TiCl4 gas was studied. The results show that Ti-ZSM-5 has a high catalytic efficiency for the epoxidation of allyl chloride. The H2O2 utilization reaches 99.50% when the allyl chloride/H2O2 molar ratio is > 1. The effect of solvent species, catalyst concentration, H2O2 and allyl chloride concentration and reaction temperature on the epoxidation was investigated simultaneously. It is found that methanol is the best solvent for the reaction. The reaction rate equation with v = k[Cat. ] [H2O2]1/2-[C3H5Cl] and the apparent activation energy with Ea = 63.462 kJ/mol are obtained according to the kinetics study.     

Effect of technological parameters on the process of epichlorohydrin synthesis

Quantitative information was obtained on how technological parameters affect the fundamental aspects of the liquid-phase epoxidation of allyl chloride to epichlorohydrin with an aqueous-methanolic solution of hydrogen peroxide in the presence of a titanium-containing zeolite in a batch reactor. The effect of the amount of a solvent, reagents ratio, and temperature was studied. The optimal conditions of epichlorohydrin synthesis were found.     

Ether formation from allylic alcohols catalyzed by samarium trichloride

The behaviour of various allylic alcohols in the presence of catalytic amounts of SmCl₃ (by heating in 1,2-dichloroethane) has been studied. Diallyl ethers are obtained in many cases in good yields. Mixed allyl alkyl ethers are also prepared if 2–5 equivalents of an aliphatic alcohol is present. The reactions are interpreted as proceeding through a pseudo allylic carbonium intermediate initiated by a preliminary complexation of the allyl hydroxyl to the samarium ion.     

Synthesis of 1,2,3,4-tetrachlorohexafluorobutane

The condensation of 1-iodo-1,2,2-trifluoro-1,2-dichloroethane induced by granulated Zn in the presence of catalytic amounts of AcOEt without a solvent results in 1,2,3,4-tetrachlorohexafluorobutane in high yield.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2236–2238, October, 2004.