Hydroxylation Reaction of Phenol to Catechol on Lanthanide-Zirconia Catalyst

ＨｙｄｒｏｘｙｌａｔｉｏｎＲｅａｃｔｉｏｎｏｆＰｈｅｎｏｌｔｏＣａｔｅｃｈｏｌｏｎＬａｎｔｈａｎｉｄｅ－ＺｉｒｃｏｎｉａＣａｔａｌｙｓｔＤｅｎｇＧｕｏｃａｉ（邓国才）；ＬｉｕＸｉｎｙｉｎｇ（刘歆颖）；ＸｕＬｉ（徐莉）ＬｉＭｅｎｇｑｉｎｇ（李梦青）；Ｍ...     

钛硅沸石TS—2催化苯酚羟基化性能研究

以用水热法合成的钛硅沸石ＴＳ－２为催化剂，考察其应用于苯酚羟基化制备苯二酚的性能。结果表明，控制适当的反应速率是提高苯酚转化率Ｈ２Ｏ２利用率的关键，反应速率与温度，原料配比，氧化剂加入方式等因素有关。选择水为溶剂，能在一定程度上抑制副反应的发生，随着催化剂再生次数的增多，苯酚转化率有所提高，产物会分布也有所变化，这可能与沸石骨架中的Ｔｋ环境发生变化有关。     

聚α-蒎烯羟基化和聚α-蒎烯大分子单体的聚合性能

用ＨＣＢｒｏｗｎ硼氢化－氧化反应对聚α－蒎烯环内双键进行羟基化，获得了羟基化结构单元为３３％～５０％的产物。羟基化产物与丙烯酰氯反应，得到了带丙烯酸酯基的聚α－蒎烯大分子单体。大分子单体（平均每条分子链上丙烯酸酯基的数目为２．７）在偶氮二异丁腈引发下进行聚合时，生成交联聚合物，聚合转化率为２０％。在相同条件下与甲基丙烯酸甲酯共聚时，大分子单体的聚合转化率可达６０％。所得聚合物中８７．５％是以甲基丙烯酸甲酯为主链、大分子单体为侧链的接枝共聚物；１２．５％是体型共聚物。     

Monodisperse microspheres of copolymers of glycidyl methacrylate and its derivatives as materials for biomedical application

Monodisperse microspheres of copolymers of glycidyl methacrylate were prepared by dispersion polymerization in organic media. The microsphere diameter could be adjusted in the range from 0$md$5 μm to 5μm by changing the monomer concentration, the type of dispersion medium and the content of the comonomers. Terpolymers of glycidyl methacrylate, 2-hydroxyethyl methacrylate and tri(ethylene glycol) dimethacrylate were analysed by thermal decomposition gas chromatography and the compositions of the polymers agreed well with those of the monomer mixtures. The epoxide of the polymer microspheres was hydrolysed to α,β-diol with dilute sulphuric acid without side reactions except the slight formation of sulphate. It was confirmed by the ¹³CFT-NMR spectrum that the main structure of the hydrolysate was that of poly(glyceryl methacrylate). In the reaction of the epoxide with ammonia, the predominant production of tertiary amine was presumed by the relationship between the conversion of the epoxide and the nitrogen content of the reaction product. The amination of the epoxide with secondary amines resulted in the quantitative formation of the corresponding tertiary amines.     

钛硅沸石TS-2的合成及表征

采用水热法在不同条件下合成出钛硅沸石ＴＳ－２。以ＸＲＤ、ＩＲ、元素分析、ＴＥＭ、ＵＶ－Ｖｉｓ和ＮＨ３－ＴＰＤ表征各样品并研究影响ＴＳ－２合成的因素。发现单聚态硅源有利于钛进入沸石骨架，而诸如Ｎａ＋等杂质电解质离子在结晶前母液中的存在则起相反作用。此结论从各ＴＳ－２样品催化苯酚双氧水羟基化时表现出巨大活性差别中得到进一步证实。ＵＶ－Ｖｉｓ测试发现２１２ｎｍ附近的强烈电子跃迁信号，不仅是四配位骨架钛的表征，也是由钛的高度分散造成的。     

As—Mo—V杂多酸盐催化苯酚羟基化制对苯二酚

合成了As-Mo-V杂多酸的十六烷基吡啶盐,元素分析和红外光谱表明,所合成的杂多酸盐具有Keggin结构。以As-Mo-V杂多酸的十六烷基吡啶盐为催化剂,苯酚过氧化氢羟基化选择合成对苯二酚时,反应温度、反应时间、催化剂用量、H2O2用量对催化性能有很大的影响。所确定的最佳反应条件为:反应温度78℃,w(催化剂)/w(苯酚)=0.4%,n(H2O2)/n(苯酚)=0.25,w(乙腈)/w(苯酚)=2,反应时间为2h。此时,苯酚的转化率为17.1%,对苯二酚的选择性为87.3%,邻苯二酚的选择性为6.6%。     

A new method for the synthesis of molybdovanadophosphoric heteropoly acids and their catalytic activities

An environmentally benign method for the synthesis of heteropoly acids H_3+n PMo_12−n V_nO₄₀·xH₂O (PMoV_n, n = 1–3) was developed by the reaction of an aqueous slurry which contained stoichiometric amounts of MoO₃, V₂O₅ and H₃PO₄. Characterization of the as-synthesized catalysts with inductively coupled plasma (ICP) elemental analysis, thermogravimetry (TG), X-ray diffraction (XRD) and infrared (IR) spectroscopy indicated that V ions substituted for Mo ions in Keggin-type phosphomolybdic acid. The assynthesized samples were found to be an efficient catalyst for the hydroxylation of benzene which was carried out in a mixed solvent of acetonitrile and acetic acid with aqueous hydrogen peroxide as oxidant. PMoV₂ exhibited the highest benzene conversion of 34.5% with phenol selectivity of 100%. Translated from Chemical Industry and Engineering Progress, 2006, 25(10): 1,171–1,174 [译自: 化工进展]     

Generation of novel landomycins M and O through targeted gene disruption

Two genes from Streptomyces cyanogenous S136 that encode the reductase LanZ4 and the hydroxylase LanZ5, which are involved in landomycin A biosynthesis, were characterized by targeted gene inactivation. Analyses of the corresponding mutants as well as complementation experiments have allowed us to show that LanZ4 and LanZ5 are responsible for the unique C-11-hydroxylation that occurs during landomycin biosynthesis. Compounds accumulated by the lanZ4/Z5 mutants are the previously described landomycin F and the new landomycins M and O.     

Epoxidation and hydroxlation of rubber seed oil: one‐pot multi‐step reactions

Epoxidized and hydroxylated rubber seed oils were prepared by peroxyformic acid generated in situ by reacting formic acid and hydrogen peroxide with RSO, a renewable resource. The structural and physico‐chemical properties of RSO have been determined. The fatty acid composition showed a high content of polyunsaturated fatty acids. The modified products were characterized with regard to their structure and properties. The findings of this study revealed that both hydroxylated and epoxidized RSO can be prepared by one‐pot multi‐step reactions.     

不同催化剂在过氧化氢氧化苯酚反应中的催化效果

主要对过氧化氢氧化苯酚反应中Fe2 + 的催化特性进行了实验研究 ,结果得出 :当Fe2 + 浓度为 0～0 0 5mmol·L-1时 ,催化活性增长显著 ,当浓度为 0 0 5～ 0 2 5mmol·L-1时 ,催化活性呈缓慢增长趋势 ,等量铁离子 (Fe3 + +Fe2 + )中不同含量的Fe3 + 对反应无明显影响。通过对相同实验条件下不同催化剂 (Fe2 + ,Cu2 + ,Fe2 + -Co2 + ,Fe2 + -Ce4+ ,Co -Fe -oxide)催化效果的研究发现 ,Fe2 + 作催化剂时苯酚与过氧化氢的转化率最高 ,Cu2 + 和Ce4+ 有利于邻 /对苯二酚含量比的提高