α-羟基环己基苯基甲酮合成工艺研究进展

α-羟基环己基苯基甲酮（光引发剂184）是一种高效光引发剂，因其引发效率高、稳定性好、耐黄变等优势，在电子、涂料、印刷等领域得到广泛的应用。本文根据起始原料不同对α-羟基环己基苯基甲酮的合成方法进行分类，并归纳了不同合成方法的特点。重点介绍了以环己基苯基甲酮为中间体的合成工艺以及其他合成α-羟基环己基苯基甲酮的工艺路线。目前，工业上最常用的Friedel-Crafts酰基化法合成光引发剂184的工艺路线，因为产生的三废多且有毒有害，不符合绿色化工的要求，而将逐渐被淘汰。以格氏反应法合成环己基苯基甲酮继而再合成α-羟基环己基苯基甲酮的工艺路线，因其收率高、污染少等优点而有望成为合成α-羟基环己基苯基甲酮的重要发展方向之一。最后，指出了α-羟基环己基苯基甲酮合成工艺研究的趋势。     

Exploring the Minimal RNA Substrate of Flexizymes

Flexizymes are tRNA acylation ribozymes that have been successfully used to facilitate genetic code reprogramming. They are capable of charging acid substrates onto various tRNAs and tRNA analogues. However, their minimal RNA substrate has not been investigated. Here we have designed fluorescently labeled short RNAs corresponding to the four, three, and two bases (4bRNA, 3bRNA, 2bRNA) at the tRNA 3′-end and explored the minimal RNA substrate of flexizymes, dFx and eFx. 3bRNA was the observed minimal RNA substrate of the flexizymes, but the efficiency of acylation of this short RNA was two to three times lower than that of 4bRNA. The efficiency of acylation of 4bRNA was comparable with that of the microhelix, a 22-base RNA conventionally used as a tRNA analogue for analyzing acylation efficiency. We also compared the efficiencies of acylation of the microhelix and 4bRNA with various acid substrates. Thanks to the short length of 4bRNA, its acyl-4bRNA products exhibited larger mobility shifts in gel electrophoresis than those exhibited by acyl-microhelix products with every substrate tested. This indicated that 4bRNA was an ideal RNA substrate for analyzing the efficiency of acylation by flexizymes.     

Differences in the chemical structure of the lignins from sugarcane bagasse and straw

Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (bagasse), and the harvest residue (straw). The structures of the lignins from these residues were studied by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). Whereas the lignin from bagasse has a syringyl-rich p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) molar composition of 2:38:60, the lignin from straw is guaiacyl-rich (H:G:S of 4:68:28). The compositional differences were also reflected in the relative abundances of the different interunit linkages. Bagasse lignin was primarily β–O–4′ alkyl-aryl ether substructures (representing 83% of NMR-measurable linkages), followed by minor amounts of β–5′ (phenylcoumarans, 6%) and other condensed substructures. The lignin from straw has lower levels of β-ethers (75%) but higher relative levels of phenylcoumarans (β–5′, 15%) and dibenzodioxocins (5–5/4–O–β, 3%), consistent with a lignin enriched in G-units. Both lignins are extensively acylated at the γ-hydroxyl of the lignin side-chain (42% and 36% acylation in bagasse and straw), predominantly with p-coumarates (preferentially on S-units) but also with acetates (preferentially on G-units) to a minor extent. Tetrahydrofuran structures diagnostically arising from β–β-coupling (dehydrodimerization) of sinapyl p-coumarate or its cross-coupling with sinapyl alcohol were found in both lignins, indicating that sinapyl p-coumarate acts as a monomer participating in lignification. The flavone tricin was also found in the lignins from sugarcane, as also occurs in other grasses.     

离子液体在金属催化剂作用下的羰基化反应中的应用

离子液体是许多有机反应的优良溶剂,能够溶解许多包括金属有机化合物在内的有机物。本文重点综述了离子液体在金属催化剂作用下的羰基化反应中的应用进展。     

1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的工艺改进

通过对1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的酰氯化反应进行正交实验优选,确定反应的最佳温度。并通过中试进行放大实验优选,确定适合生产的最佳工艺参数。特定配比溶剂的酰氯化反应最佳反应温度为42℃～45℃,反应时间3小时,所得收率最高可达87%,质量可达99%（ HPLC）。该实验优选的反应工艺参数重复性好,所得收率最高,缩减了生产周期,使生产可在当天内完成,便于生产车间工作安排。     

“一锅三步法”合成苯基-2-吡啶基甲醇

以2-苄基吡啶氮氧化物和三氟乙酸酐为原料，通过“一锅三步法”（串联“酰化、[3,3]σ重排和水解”反应）合成了关键药理活性中间体苯基-2-吡啶基甲醇，并对反应条件进行了优化。结果表明：当n（2-苄基吡啶氮氧化物）：n（三氟乙酸酐）=1 : 1.2、N, N-二异丙基乙胺（DIPEA）为碱、甲苯为反应溶剂，室温反应6小时，经硅胶柱层析分离即可得到苯基-2-吡啶基甲醇，收率为81.0%。产物经1H NMR，13C NMR 和HRMS进行结构表征。本文以原子经济学的理念首次实现了由2-苄基吡啶氮氧化物到苯基-2-吡啶基甲醇的直接转化。     

木素胺化改性制备重金属吸附剂

以木素为原料,通过胺化改性制备木素基重金属吸附剂,吸附Pb2+。实验中首先将木素用琥珀酸酐进行酸酐改性,然后以对甲苯磺酰氯为催化剂与三乙烯四胺反应,得到胺化改性木素。以琥珀酸酐与木素摩尔比及反应时间为变量优化酸酐改性条件。通过测定羧基含量、红外光谱分析(FT-IR)和吸附性能分析对产物性能进行表征。结果表明,琥珀酸酐与木素摩尔比1.5∶1、反应时间1 h、温度28℃、pH值8.5~9.0时,所得酸酐改性木素中羧基含量最高,达1.98 mmol/g;FT-IR谱图分析显示木素改性成功;胺化改性木素对Pb~(2+)吸附符合拟二阶动力学模型和Freundlich模型,同时随着pH值的升高,产物吸附性能随之提高,p H值5时吸附性能降低,在p H值为5时胺化改性木素对Pb~(2+)的吸附量达到152.95 mg/g。     

Catalytic performance of methacrylate‐based poly‐4‐(dialkylamino)‐pyridines: activity prediction via NMR shifts

The synthesis of the 4‐(dialkylamino)pyridine derivative 3‐(4‐(pyridin‐4‐yl)piperazin‐1‐yl)propyl methacrylate and its copolymerization with n‐butyl methacrylate are presented. The catalytic activity was evaluated in the acylation of tert‐butanol with acetic anhydride yielding tert‐butyl acetate. It is observed that the activity of polymer‐attached 4‐(dimethylamino)pyridine analogues correlates remarkably well with the chemical shift of the β‐pyridyl protons. Differences in catalytic efficiency result from distinct electronic densities of the pyridine ring, while embedding the catalytically active moiety into a polymeric structure has nearly no deleterious effect on the performance. © 2015 Society of Chemical Industry     

水力空化作用强化硬脂酰氯酰化大豆蛋白工艺的研究

以大豆粕为研究对象,通过水力空化作用强化硬脂酰氯酰化大豆蛋白工艺。利用自行设计的水力空化强化装置,采用单因素实验研究了水力空化压力、水力空化时间、水力空化温度、料液比对硬脂酰氯酰化大豆蛋白产物产率的影响。在此基础上,利用响应面优化了水力空化作用强化硬脂酰氯酰化大豆蛋白工艺条件,并对硬脂酰氯酰化大豆蛋白产物表面活性进行测定。结果表明:水力空化作用强化硬脂酰氯酰化大豆蛋白最优工艺条件为水力空化压力0.37 MPa、水力空化时间60min、水力空化温度58℃、料液比1.7∶1,此条件下的产率为95.27%;硬脂酰氯酰化大豆蛋白产物表面活性性能优越。