中孔分子筛Al-MCM-41制备及催化合成二芳基乙烷

以硅酸钠为硅源、硫酸铝为铝源、CTAB为模板剂,采用水热法合成了负载型固体酸Al-MCM-41中孔分子筛催化剂,并通过X射线衍射（XRD）、热重差热分析（TG-DTA）、扫描电镜（SEM）和红外（IR）方法对其进行了表征,同时研究了该催化剂在二芳基乙烷合成反应中的催化性能。考察了各种反应因素的影响,确定其最佳合成条件为：原料苯乙烯与二甲苯质量之比为1∶7.5,催化剂用量为1 %(总投料质量百分比),反应时间为3 h,反应温度为140 ℃,产率可达87.1 %,比传统催化剂浓硫酸提高了17 %。研究结果表明,该催化剂是替代液体酸合成二芳基乙烷的理想固体酸催化剂。     

固体超强酸ZrO_2/S2O_8~(2-)催化合成肉桂酸甲酯

研究了在固体超强酸ZrO2/S2O2-8催化下,肉桂酸与甲醇作用合成肉桂酸甲酯的工艺.考查了催化剂的用量、酸醇摩尔比、反应时间及催化剂的性能对反应的影响.最佳反应条件为∶n(肉桂酸)∶n(甲醇)=1∶10,m(肉桂酸)∶m(催化剂)=3∶1,反应温度90～95℃,反应时间5h,酯化率为95.7%.     

对硝基邻苯二乙醚合成技术研究

以邻苯二酚与溴乙烷为原料、聚乙二醇为相转移催化剂合成邻苯二乙醚,再经过冰醋酸和硝酸硝化得到对硝基邻苯二乙醚。研究了反应温度、反应时间、原料摩尔比和催化剂用量等对反应收率的影响,获得了合成邻苯二乙醚的优化工艺条件:n(C6H4(OH)2)∶n(NaO H)∶n(C2H5Br)=1∶2.6∶2.4,反应温度80℃,反应时间4h,催化剂用量2g,该反应条件下邻苯二乙醚平均收率88%。混酸硝化条件下合成对硝基邻苯二乙醚的较佳工艺条件为n(C10H14O2)∶n(HNO3)=1∶1.2,乙酸25mL,反应时间30min,反应温度20℃,该反应条件下对硝基邻苯二乙醚平均收率为99%。     

一种新型芳基硫鎓盐光引发剂的合成及应用

将二苯二硫醚作为硫源与1-甲基-2-苯基吲哚反应合成了含杂原子环的硫醚类化合物,然后再与二芳基碘三氟甲磺酸鎓盐反应,合成了一种新的芳基硫鎓盐。采用1 HNMR、MS等技术对目标化合物进行了表征,并确定了最佳反应条件。在硫醚类化合物与二芳基碘三氟甲磺酸鎓盐的摩尔比为1∶1.2,催化剂为CuI/Cu,溶剂为1,1,2,2-四氯乙烷的反应条件下,目标化合物的产率达到了62.0%。同时,对这类结构的芳基硫鎓盐进行了紫外光固化性能测试,发现其能够在紫外光固化体系中作为阳离子光引发剂得到应用。     

纳米复合固体超强酸S_2O_8~(2-)/CoFe_2O_4催化合成癸二酸二乙酯

将硫酸钴、硫酸亚铁在NaOH溶液中与NaHCO3反应制得碱式碳酸盐前驱体 ,后者用 (NH4 ) 2 S2 O8浸渍、干燥 ,再经 5 0 0℃焙烧得到固体超强酸催化剂S2 O2 -8/CoFe2 O4 。产物经XRD、TEM、BET、TG DTA及化学法等检测 ,含硫量 4 5 2 % ,粒径为 4 2nm ,比表面积为 1 4 6m2 /g ,粒度均匀。催化剂的酸强度处于 -1 6 0 2和-1 4 5 2之间。以该固体酸为催化剂 ,由癸二酸和无水乙醇合成了癸二酸二乙酯。最佳反应条件为 :n(醇 )∶n(酸 ) =4 0∶1 0 ,癸二酸 0 1mol,催化剂 1 0 g ,反应时间 2 5h。在此反应条件下 ,酯化率可达 93 6%。     

固载杂多酸SiW_(12)/C催化合成富马酸二甲酯

用自制的固体杂多酸催化剂SiW12 /C进行催化酯化合成富马酸二甲酯 (DMF) .探讨了催化剂用量、醇 /酸比、反应时间、反应温度等动力学条件对合成DMF的影响 .确定了合成DMF的最佳合成工艺条件 :醇 /酸物质的量比为 6∶1,催化剂用量为富马酸质量的 2 .5 % ,反应时间 7.0h ,反应温度为回流温度 ,酯化率可达 90 .6 % .结果表明 ,该催化剂催化活性高 ,可重复使用 ,后处理容易 ,生产成本低且无三废污染 .     

改性Raney Ni催化剂用于加氢合成间苯二甲胺

采用改性RaneyNi催化剂,研究了溶剂、温度、压力、催化剂用量对间苯二甲腈(IPN)加氢合成间苯二甲胺(m-XDA)反应的影响.结果表明,该催化剂在以甲醇、甲苯为混合溶剂,V(甲醇)∶V(甲苯)=1∶2,当m(溶剂)∶m(IPN)=3∶1,反应温度70℃、压力6.0MPa～7.0MPa、催化剂用量为原料质量的10%时,IPN转化率接近100%,m-XDA收率达97%.失活催化剂经再生,即能恢复其性能.     

微波辐射下离子液体催化合成α-溴代芳基酮

在微波辐射下,离子液体催化苯乙酮或取代苯乙酮和N-溴代丁二酰亚胺(NBS)反应合成了7种α-溴代芳基酮,收率为73%～95%.最佳反应条件为:甲醇为溶剂,n(芳基酮)∶n(NBS)=1∶1,酸性离子液体MIM-PS-CH3SO3H为40 mol%,微波辐射功率为50或250 W.该反应时间短、产率高、环境友好、后处理方便、催化剂可重复使用.产物的结构经1H NMR,IR确证.     

稻壳灰负载氯磺酸催化5-取代四氮唑环的合成研究

以稻壳吸附负载氯磺酸为固体酸催化剂,在微波辅助条件下,利用芳基腈和叠氮化钠在DMF溶剂中环加成反应一步法制备得到5-取代四氮唑类化合物(3a-3k),其结构经IR、~1H NMR和元素分析等确证.实验结果表明,所制备的固体酸催化剂用量20%,在400 W和120℃下微波辐射反应20～35 min,即可得到目标化合物且合成收率为82%～95%,该方法具有操作简单、催化剂易回收且可多次使用等优点.     

1,4-二乙氧基苯的相转移催化合成

采用大孔型交联聚苯乙烯为载体研制出新型季 钅盐型相转移催化剂Y98B ,并将其应用于 1 ,4-二乙氧基苯的催化合成反应 ,产品进行了红外光谱分析和熔点测定 ,探讨了催化剂用量、对苯二酚与溴乙烷物质的量比、反应温度和反应时间等动力学条件对产品收率的影响。确定了在反应温度为 70℃、对苯二酚∶溴乙烷 (摩尔比 )为 1∶3.5、反应时间为 4h、催化剂用量为 3.0g的条件下产品收率可达 84.3%     

Synthesis and characterization of mesoporous molecular sieves

In the synthesis of mesoporous molecular sieves of the type MCM-41, different cationactive surfactants and sources of silicon were used. Moreover, Al-MCM-41 samples with different content of aluminium were synthesized. MCM-41 and Al-MCM-41 were synthesized at elevated temperature in stainless-steel autoclaves. Prepared mesoporous molecular sieves were characterized by powder X-ray diffraction (XRD), physical adsorption of nitrogen at the temperature of −197°C, sorption capacity of benzene, and by infrared spectroscopy (FTIR). Acidity was measured for Al-MCM-41 by temperature programmed desorption of ammonia (TPDA) and by FTIR of adsorbed pyridine. Acid catalytic activity of Al-MCM-41 was tested by isomerization of o-xylene. Influence of the synthesis reproducibility, surfactant used, source of silicon, synthesis time, source of aluminium, and Si to Al mole ratio on the properties of mesoporous molecular sieves were evaluated.     

Al-MCM-41介孔分子筛催化对甲酚叔丁基化反应的研究

2-叔丁基对甲酚是一种有机中间体,在有机合成领域中占有重要地位,被广泛应用于表面活性剂、高档酚类抗氧化剂2246和2246-S、紫外线吸收剂UV-326等的生产[1]。特别是近十年来,以抗热老化为特征的功能性高档酚类抗氧化剂在国内外相继问世,它们对于提高聚合物材料的成型加工性能、     

Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes

Mesoporous aluminosilicate (Al-MCM-41) was found to catalyze the allylation of both aromatic and aliphatic aldehydes with allylsilanes although amorphous silica-alumina or mesoporous silicates (MCM-41, SBA-15) could not catalyze the reaction under the same reaction conditions. The solid acid catalyst Al-MCM-41 could be reused three times without significant loss of activity.     

介孔分子筛Al-MCM-41接枝三甲基氯化锡的合成、表征及催化性能

将三甲基氯化锡与Al-MCM-41介孔分子筛在N2气气氛中135 ℃回流4.5 h,得到表面键合有机锡的分子筛(CH3)3Sn-O-MCM-41[(CH3)3SnM]。 采用电感耦合等离子体质谱（ICP-MS）、有机元素分析、红外光谱、N2吸附-脱附、热重分析（TG）、NH3程序升温脱附（NH3-TPD）、X射线多晶衍射（XRD）和透射电子显微镜等测试技术对样品的组成、结构和表面物理化学性质进行表征。 结果表明,有机锡接枝率可达14.44%;接枝前后分子筛的NH3-TPD表面酸量(NH3)由0.652 6 mmol/g增加至1.294 4 mmol/g。 接枝后分子筛的比表面积减小,孔容变大,孔径变小,仍保持六方介孔结构;接枝分子筛(CH3)3SnM用于催化合成乙酸异戊酯,当n(异戊醇)∶n（冰乙酸）=1.0∶1.0,w（催化剂）=5%,138 ℃,回流5 h,反应转化率为96%;催化剂重复使用5次,酯化转化率仍可达到86%。     

Mesoporous aluminosilicate-catalyzed allylation of carbonyl compounds and acetals

A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both carbonyl compounds and acetals with allylsilanes to afford the corresponding homoallyl silyl ethers and homoallyl alkyl ethers, respectively. Both the mesoporous structure and the presence of aluminum moiety were indispensable for the high catalytic activity of Al-MCM-41. Moreover, Al-MCM-41 could catalyze the reaction of acetals chemoselectively in the presence of the corresponding carbonyl compounds. The solid acid catalyst Al-MCM-41 could be recovered easily by filtration and could be reused three times without a significant loss of catalytic activity.     

Reaction of benzaldehyde with various aliphatic glycols in the presence of hydrophobic Al-MCM-41: A convenient synthesis of cyclic acetals

The reaction of benzaldehyde with aliphatic glycols was performed over Al-MCM-41 with various Si/Al ratios. The effects of various parameters like temperature, mole ratio, reaction time and catalyst amount on the formation of acetals were optimized. The mesoporous Al-MCM-41 (Si/Al ratio 36, 57, 81 and 108) were synthesized by hydrothermal method. The synthesized catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherm (BET), thermo gravimetric-differential thermal analysis (TGA-DTA) and TEM techniques. The acidity of the catalysts was measured by pyridine adsorption followed by FT-IR analysis. TEM analysis showed that the honeycomb-like regular arrangement of hexagonal pores on the molecular sieves. The highly hydrophobic Al-MCM-41 (108) showed higher activity than the other Si/Al ratios. The activity of the catalysts showed the following order Al-MCM-41 (108) > Al-MCM-41 (81) > Al-MCM-41 (57) > Al-MCM-41 (36). The hydrophobicity and nucleophilicity of the glycols highly influences the conversion of benzaldehyde, it followed the order; hexylene glycol (HG) > propylene glycol (PG) > ethylene glycol (EG). The results showed that mole ratio of 1:3 (aldehyde:glycol) gave higher yield than the other mole ratios.     

Mesoporous material as catalyst for the production of fine chemical: Synthesis of dimethyl phthalate assisted by hydrophobic nature MCM-41

Aluminum, iron and zinc containing MCM-41 molecular sieves were prepared by the hydrothermal method. The catalyst was characterized by the XRD, BET (surface area), FT–IR and ²⁹Si, ²⁷Al MAS–NMR techniques. The catalytic activity of these molecular sieves was tested with esterification reaction used with phthalic anhydride (PAH) and methanol (MeOH) in the autoclave at 135 °C, 150 °C and 175 °C. Conversion increases with an increase in temperature and mole ratio. The activity of these catalysts followed the order: Al-MCM-41 (112) > Fe-MCM-41 (115) > Al-MCM-41 (70) > Al-MCM-41 (52) > Fe-MCM-41 (61) > Al, Zn-MCM-41 (104) > Al-MCM-41 (30). The reaction yielded both monomethyl phthalate (MMP) and dimethyl phthalate (DMP). The nature of the catalyst sites has been proposed using with water as an impurity. The selectivity of the dimethyl phthalate increases with increase in temperature and mole ratio. The weight of the catalyst was optimized at 0.07 g. The hydrophilic and hydrophobic nature of the catalyst has been explained by the influence of water and the external surface acidity also facilitates the reaction and this has been confirmed by the supporting reaction.     

Mesoporous aluminosilicate-catalyzed Mukaiyama aldol reaction of aldehydes and acetals

A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both aldehydes and acetals with silyl enol ethers or ketene silyl acetals to give the corresponding aldol adducts in moderate to high yields. The remarkable high catalytic activity of Al-MCM-41 over amorphous silica-alumina and aluminum-free mesoporous silicate was observed in the reaction. The solid acid catalyst could be recovered easily by filtration and the recovered catalyst was reusable in the same reactions without a significant loss of catalytic activity.     

Mesoporous aluminosilicate-catalyzed Sakurai allylation and Mukaiyama aldol reaction of acetals

In the presence of a catalytic amount of mesoporous aluminosilicate (Al-MCM-41), both allyltrimethylsilane and silyl enol ether reacted with various acetals under mild reaction conditions to afford the corresponding homoallyl ethers and β-alkoxy ketones, respectively. The catalyst was easily recovered from the reaction mixture and could be reused in the same reaction without a significant loss of catalytic activity. Moreover, Al-MCM-41 exhibited high chemoselectivity for acetal over aldehyde in the reactions.