载体催化法合成第三代头孢菌素母核7-ANCA

解决以青霉素钾盐为原料合成7-氨基-3-无-3-头孢环-4-羧酸(7-ANCA)的过程中,氧化反应成本高、操作难度大的问题。方法:制备纳米羟基磷灰石,将三价钌负载于纳米材料上,制得钌-纳米羟基磷灰石(Ru-HAP)载体催化剂,用此试剂代替常规的氧化剂臭氧或者三氯化钌催化碳碳双键氧化断裂成醛的反应。结果:反应条件温和易控制,污染小;产品质量好,收率高;催化剂回收容易。结论:选择新型载体催化剂——钌纳米羟基磷灰石(Ru-HAP)催化烯烃的氧化断裂,反应稳定性好,贵金属容易回收,反应绿色环保,工业三废少,最终产品生产成本低。     

在Mo-Bi-P_(2.2)/SiO_2催化剂上丁烯异构化L-H三角反应机理复杂反应动力学

用玻璃外循环无梯度反应器研究了丁烯异构化L-H三角机理复杂反应动力学.X衍射分析指出Mo-B_1-P_2.2/SiO_2催化剂含有磷酸铋物相.用吸附指示剂正丁胺滴定法测定了催化剂的酸量.催化剂显中等强度的酸性.催化剂上吸附吡啶的红外光谱法测定了质子酸和路易斯酸.气相色谱法测定了1-丁烯、2-丁烯吸附热.讨论了1-丁烯异构化表观活化能与真活化能的关系.用正交设计法估计了动力学方程中的参数.异构化生成反-2-丁烯及顺-2-丁烯的动力学方程分别为式(11)、(12)所描述.     

油脂合成C_(22)二元酸及三元酸的研究

以梓油及棉籽油为原料 ,对顺 -反式共轭酸与马来酐的双烯加成反应进行了研究 ,探讨了不同的催化剂用量、反应时间对合成反应的影响 ,获得了 90 %以上的得率     

反-4-乙基环己基甲酸的合成

4 乙基苯甲酸(2PA)在钌/碳催化剂存在下,加氢合成顺反 4 乙基环己基甲酸(2HA)混合物。异构化反应以氢氧化钾为催化剂,催化剂与2HA的摩尔比为2 0,在无溶剂、温度为180℃的条件下进行,产物反 4 乙基环己基甲酸(trans 2HA)与顺 4 乙基环己基甲酸(cis 2HA)的质量比可达到96∶4。     

吡啶二亚胺钌配合物催化酮的氢转移氢化反应

以2,6-二[1-(苯基亚胺基)乙基]吡啶与三苯基膦氯化钌的配合物为催化剂,考察了苯乙酮的氢转移氢化反应.在苯乙酮、钌配合物和KOH的初始摩尔比为250∶1∶12、反应温度为82℃时,反应2 h后苯乙酮的转化率达到98.3%.研究了反应温度、底物浓度、碱强度等对氢转移催化反应的影响.结果表明,这种吡啶二亚胺钌配合物对苯乙酮等的氢转移反应具有良好的催化性能.     

4-烯丙氧基-2,6-二(N,N-二乙胺基甲基)吡啶钌配合物催化苯乙酮氢转移反应

以配体4-烯丙氧基-2,6-二(N,N-二乙胺基甲基)吡啶与三苯基膦氯化钌配位化合物生成新的钌催化剂,催化苯乙酮氢转移反应。考察温度、碱强度、底物浓度及产物等对反应的影响。研究结果表明:在N2气氛下,82℃,苯乙酮、钌配合物和KOH的初始摩尔比为250∶1∶12,反应6 h,苯乙酮的转化率达到99.8%,该催化剂具有很好的催化活性和稳定性。     

乙炔氢氯化反应用催化剂的制备及优化

在固定床反应器上评价不同种类助剂制备的催化剂活性来筛选较适宜的活性组分组合,通过正交设计优选出无汞催化剂的基础配方,考察了添加0.6%的三氯化钌、氯化钯、氯化银等贵金属活性成分及氯化汞后催化剂的活性情况,并进一步优化三氯化钌、氯化汞质量分数来提高催化剂活性。结果表明:助剂氯化钡较氯化钠、氯化铈更能与氯化亚铜/氯化铋间相互协同催化;活性炭上负载12%Cu Cl、16%Bi Cl3、4%Ba Cl2时制备的催化剂活性最佳,转化率可高达66.4%,继续添加氯化银能提高稳定性,但并不能改善催化剂的活性,添加氯化钯仅能改善反应初期催化剂活性,随着反应进行活性不断降低,而添加三氯化钌及氯化汞后催化剂活性明显提升,质量分数为1%时,平均转化率在72.2%以上,特别是氯化汞的转化率可增加至92%,较未加前增加了27%。     

反-4-(反-4′-正丙基环己基)-环己基甲醛的合成与表征

以反-4-(4'-正丙基环己基)-苯甲醛丙二醇缩醛为起始原料,经加氢、酸解及异构化反应得到纯度98%以上的反-4-(反-4'-正丙基环己基)-环己基甲醛,总收率为39.2%,目标化合物的结构经1HNMR、IR及GC-MS确认。探讨了反-4-(4'-正丙基环己基)-苯甲醛丙二醇缩醛加氢的反应条件,实验表明,以钌/碳为催化剂,乙醇为反应溶剂,当m[反-4-(4'-正丙基环己基)-苯甲醛丙二醇缩醛]∶m(钌/碳)=1∶0.09,加氢压力为3.5 MPa,反应温度为35~40℃时,反应效果最佳。     

含1,3,4-噁二唑和偶氮苯结构聚合物单体的合成

以间苯二甲酸为初始原料合成一种新型化合物5-[4-(十六烷氧基)苯基偶氮]-1,3-苯基-二(1,3,4-噁二唑硫)乙酸甲酯,采用IR、UV-vis和1H NMR对中间体和目标化合物结构进行了表征.365 nm紫外光照射下,5-[4-(十六烷氧基)苯基偶氮]-1,3-苯基-二(1,3,4-噁二唑硫)乙酸甲酯中偶氮苯结构发生光致反-顺异构化现象,计算得到光致反-顺异构化转化效率(R)、光稳态时顺式异构体含量(Y)及反-顺异构化速率常数(Kp)分别为80.95％、84.99％、和1.3389 min-1.     

催化加氢制备低反-反异构PACM用负载型Ru催化剂研究

采用浸渍法制备了不同载体负载钌催化剂，并考察其催化4,4’-二氨基二苯基甲烷(MDA)液相加氢制备反-反异构PACM性能，重点研究了第二金属助剂协同催化对催化剂综合性能的影响。结果表明，添加金属Re后催化剂活性、选择性均有明显提升，最优的Ru∶Re金属负载比例为5∶1,此时反-反异构体含量低于20%,且催化剂具有良好的稳定性。     

Hydrogenation and deuteration of conjugated isomers of linoleate and linolenate with palladium,platinum, nickel and lindlar catalysts

Conjugated isomers of methyl linoleate and linolenate were reduced with palladium, platinum, nickel and Lindlar catalysts at atmospheric hydrogen or deuterium pressure. After the products were separated, positions of their double bonds were determined by ozonolysis. Palladium and platinum catalysts reduced β-eleostearate directly to monoene. Nickel reduced β-eleostearate to dienes chiefly by 1,2-addition and to a lesser extent by 1,4- and 1,6-addition, whereas Lindlar catalyst reduced by 1,2-and 1,6-addition only. All catalysts reduced conjugated linoleate isomers by both 1,2- and 1,4-addition, with nickel being somewhat preferential for 1,2-addition. Selectivity for the catalytic reduction of dienes to monoenes decreased in the order: nickel, palladium and platinum. Lindlar catalyst did not isomerize or reduce monoenes that formed during reduction. Palladium and platinum did not isomerize conjugated dienes and trienes during their reduction, whereas nickel and Lindlar catalysts isomerized them slightly. Some deuterium was found in unreacted conjugated diene and triene with nickel and Lindlar catalysts, but none with palladium or platinum. Deuterated products contained a wide range of isotopic isomers with some products having up to 31 deuterium atoms. This wide deuterium distribution resulted from (a) exchange followed by addition, (b) addition followed by exchange and (c) exchange-addition-exchange reactions. Presented at the AOCS Meeting, Atlantic City, October 1971. ARS, USDA.     

Hydrogenation ofcis-9,cis-12-,cis-9,trans-12- andtrans-9,trans-12- Octadecadienoates

The products formed by hydrogenation of methylcis-9,trans-12- andtrans-9,trans-12-octadecadienoates with nickel and platinum catalysts have been compared with those from methyl esters of the naturally occurring all-cis linoleate. Hydrogen uptake is slower for thetrans isomers. Much of the monoene consisted of esters with double bonds at the 9 and 12 positions with their original geometric configurations. Monoenoic esters with double bonds at the 10 and 11 positions were predominatelytrans and apparently formed by conjugation before hydrogenation. Nickel produced more isomerization than platinum but less than previously reported for copper. With both catalysts hydrogenation proceeded both directly and through conjugated intermediates, in contrast to copper in which all hydrogenation is believed to follow conjugation. Presented at the AOCS Meeting, Los Angeles, April 1972. ARS, USDA.     

Selective hydrogenation with copper catalysts: I. Isolation and identification of isomers formed during hydrogenation of linolenate

Methyl linolenate was hydrogenated with 10% copper chromite catalyst at 150 C and atmospheric hydrogen pressure. The product was separated into monoene, diene and triene fractions by countercurrent distribution. These fractions were further separated into various geometrical isomers. The double bond location in the various fractions was determined by reductive ozonolysis. Double bonds in bothcis andtrans monoene fractions, as well as incis,trans andtrans,trans conjugated dienes, were extensively isomerized. A monoene containing vinylic unsaturation was one of the major products. The nonconjugated dienes were mostly dienes whose double bonds were widely separated. Results are explained on the basis of conjugation of the double bonds in linolenate followed by hydrogen addition. Presented in part at the symposium “Hydrogenation Process,” Division of Industrial Engineering Chemistry, 157th American Chemical Society Meeting, Minneapolis, April 1968. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Selective hydrogenation with copper catalysts: II. Kinetics

To explain the unusually high selectivity of copper catalysts toward linolenate, model compounds were hydrogenated (150 C and atmospheric pressure) and the reaction products analyzed. Products varied depending upon location of the double bonds. Monoenes were not reduced by copper chromite except when the double bond was next to a carboxyl group. Dienes with isolated double bonds also were not reduced. Binary mixtures of model compounds were hydrogenated with copper chromite. From the composition of the initial and final products, a competitive rate ratio of the two compounds was determined. Esters with conjugated double bonds reacted faster than esters containing methylene interrupted double bonds. Kinetic data on the hydrogenation of linolenate indicated conjugation of the double bonds. Simulation of the kinetic data gave competitive reaction rates for the different isomers formed. Presented at the AOCS Meeting, New York, October 1968. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Selective hydrogenation with copper catalysts: III. Hydrogen addition and isomerization

β-Eleostearate was found to be reduced by 1,6 addition of hydrogen. Because of the extensive isomerization of conjugated trienes during hydrogenation, the occurrence of 1,2 and 1,4 addition reactions could not be proven. Conjugated dienes were reduced by both 1,2 and 1,4 addition of hydrogen. The double bond distribution in the products formed from linoleate, linolenate and their isomers was consistent with the assumption that the double bonds in polyunsaturated fatty esters conjugate and then add hydrogen. Extensive isomerization (positional and geometric) of the conjugated double bond systems occurred during hydrogenation. Monoenes were not isomerized under similar conditions of hydrogenation. Since double bond distribution in monoenes formed from linoleate and alkali-isomerized linoleate was identical, indications are that conjugation precedes hydrogenation. Presented in part at the symposium “Hydrogenation Process,” Division of Industrial Engineering Chemistry, 157th American Chemical Society Meeting, Minneapolis, April 1968. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Hydrogenation of unsaturated fatty esters with copper-chromite catalyst: Kinetics,mechanism and isomerization

Hydrogenation of linolenate with copper chromite produced a large amount of conjugated diene and minor amounts of nonconjugatable dienes. The double bonds in conjugated dienes and monoenes were scrambled all along the chain. This product distribution can be explained if it is assumed that conjugation of the double bonds is followed by hydrogenation. In competitive hydrogenation, fatty esters with conjugated double bonds were reduced preferentially over fatty esters with methylene-interrupted double bonds. Isomerization of conjugated double bonds (geometric and positional) occurred more rapidly than reduction. Reduction of conjugated double bonds in the presence of deuterium resulted in a majority of the products containing no deuterium. Most of the added deuterium was incorporated into the unreacted material. Mechanisms are proposed to account for the products formed during the hydrogenation of linolenate, linoleate and their isomers. One of 10 papers to be published from the Symposium “Hydrogenation,” presented at the AOCS Meeting, New Orleans, April 1970. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Isomerization of the double bonds of a conjugated fatty acid during β-oxidation

The β-oxidation of an unsaturated fatty acid containing conjugated double bonds at odd-numbered carbon atoms has not previously been studied. It is, therefore, not clear whether, during the β-oxidation of such an acid, the double bonds will be isomerized by enoyl-CoA isomerase (Δ³-Δ²-enoyl-CoA isomerase) with the loss or retention of its conjugated nature. To investigate the problem, (E,E)-3,5-octadienoyl-CoA was synthesized for use as a model substrate, and enoyl-CoA isomerase was partially purified from bovine liver. The isomerization was followed by spectrophotometric and gas liquid chromatographic methods, and the results suggested that the isomerization of the model substrate proceeded with retention of a conjugated double bond system. It is, therefore, proposed that the β-oxidation intermediate of α-eleostearic acid (Δ^9,11,13 fatty acid) will also isomerize with retention of the conjugated double bond system. Part of doctoral thesis submitted to University of Pretoria, Pretoria, 0001, Republic of South Africa.     

Rubber substrates and their influence on isomerization of conjugated dienes in pheromone dispensers

Release rate and degree of isomerization of pheromones with conjugated double bonds were studied in dispensers prepared from several rubber substrates. The substrates compared were made of rubber, cured with elemental sulfur or accelerators based on organic sulfur compounds or organic peroxides. Isomerization of the double bonds occurs immediately after impregnation of the substrate, and the degree of isomerization increases during field use and/or storage. The propensity of the isomers to isomerize corresponds to their proportion in the equilibrium mixture. AnE,Z isomer is isomerized faster than theE,E isomer, and finally a near-equilibrium mixture of the four isomers is present. Minimal isomerization was found in non-sulfur-cured substrates which are the material of choice.     

The correlation between electrical properties and structure of substituted polyacetylenes

Summary The electrical conductivity of polyphenylacetylenes and polyhalophenylacetylenes was measured in dependence on the temperature and on the type of catalyst used for polymerization. The electrical conductivity increased with increasing temperature. The energy gap was calculated from the temperature dependence on the electrical conductivity; it decreased with increasing number of conjugated double bonds in the polymer chain and with the regularity of structure of the polymer. The number of double bonds, cyclization and configurations were determined by ¹H and ¹³C-NMR. In polyphenylacetylenes only aliphatic carbons deriving from cyclohexadiene units were found but no such units were found in polyhalophenylacetylenes. By UV-vis measurement the number of conjugated double bonds in segments was estimated. The synthesized polymers were amorphous. Their molecular weight was between 2000 and 74.000.     

Synthesis and rheological study of some maleic acid polyamides

The contributions of the cis and trans configurations of the main chain double bonds to the transition temperatures and rheological properties were determined for four well-defined polymaleamides, which were prepared by the room temperature ring-opening, step-growth polymerization reactions of N,N′-bisisomaleimide monomers with bifunctional primary diamines. The polymaleamides were glassy solids, which could be thermally isomerized into related polyfumaramides. The glass transition temperatures of the polyfumaramides, as determined by mechanical spectrometry, are systematically and markedly higher than those of the polymaleamides from which they were derived.