Direct reductive amination of camphor
Terpenoids are an irreplaceable class of natural products. The camphoryl group is an important moiety in the structure of chiral ligands for asymmetric synthesis catalysis or it can be used as an auxiliary group in asymmetric synthesis.[1] The usage of fenchone based molecules for asymmetric catalysis and synthesis is less common because of the difficulty of fenchone modifications due to steric hindrance. Camphor is a readily available starting molecule for the preparation of different compounds with biological activity. For example, camphor diimines demonstrate antiviral activity.[2] Fenchonyl amine-based molecules are potential therapeutic agents for the treatment of Alzheimer’s disease. Amines are a crucial class of organic compounds with multiple academic and industrial applications. There are a plethora of synthetic approaches towards amines synthesis and modifications, reductive amination being one of the most powerful and useful methods. However, the reductive amination of camphor and fenchone remains a challenge. A standard approach to reductive amination with amines other than ammonia and methylamine includes two steps: preparation of azomethines or Schiff bases in the presence of strong Lewis acids and their reduction with more or less conventional reducing agents. The synthesis of fenchonyl amines is even more challenging. There is no universal approach, and almost every manuscript reports some particular protocol different from others. In most cases, the first stage of this process requires quite harsh conditions. For example, the preparation of a Schiff base from camphor and 1-phenylethylamine requires 5-10 days of heating at 150°C.[3] Schiff bases of other primary amines could be prepared under similarly harsh conditions. Preparation of enamines is possible using titanium tetrachloride as a catalyst. The reduction also might be challenging. Sodium borohydride or sodium cyanoborohydride was described as suitable for this goal in several reports.[4] To the best of our knowledge, no papers describe any general approach for the direct reductive amination of camphor or fenchone. There is only one example of camphor direct reductive amination without an external hydrogen source using carbon monoxide as a reducing agent. This protocol is very efficient but its application is limited by the necessity of carbon monoxide and high-pressure equipment for the reaction setup.
利用硫醇分子合成金奈米團簇應用於檢測自來水及游泳池水中次氯酸根
隨著大眾對於衛生要求的上升，許多抗菌及消毒成分被廣泛應用於水質處理中，其中次氯酸作為消毒殺菌劑大量使用於泳池及自來水的水質淨化中，然而現行標準方法測定水中有效氯所使用具危害的毒化物且步驟繁雜不利普及民生使用，發展簡便快速且靈敏的偵測方法勢在必行。本研究利用牛血清白蛋白（Bovine serum albumin, BSA）、不同的硫醇分子及金離子合成具螢光特性之硫醇修飾金奈米團簇 （Thiol ligand assists BSA capped gold nanoclusters, BSA/RSH-Au NCs），探討添加不同硫醇分子對所合成之金奈米團簇於不同pH值及常見離子對螢光強度之影響，並利用具有最佳螢光穩定性之2-巰基苯甲酸修飾金奈米團簇（Thiosalicylic acid assists BSA capped gold nanoclusters, BSA/TA-Au NCs），透析後進行次氯酸根檢測，其檢測線性範圍為0.98μM-1000μM，涵蓋法規規定游泳池水及自來水中次氯酸根之容許殘留濃度，最後此方法成功於游泳池水及自來水基質中檢測次氯酸根，分析樣品的回收率介於94.4%-95.6%。此外，在紙上添加金奈米團簇，並加入不同濃度的次氯酸根，觀察其螢光強度的變化，期望此方法未來應用於快篩試紙塗布材料快速檢測水質中次氯酸根濃度。
Synthesis of Macro Porous Activated Carbon from Waste Polyethylene Terephthalate (PET) Bottles and Investigation of Usability in Dye Removal from Water Sources
Colorants are used in many industries, especially in the textile industry. These substances both cause visual pollution and create an anaerobic environment for aquatic creatures. In this study, it is aimed to examine the usability of activated carbon synthesized from waste polyethylene terephthalate (PET) bottles, which is an important environmental problem, in removing the pollution caused by the colorants caused by industrial activities in water resources.
Synthesis of Mesoporous Carbons and Their Application for EDLC
The quick increasing energy consumption arouses the interest in the development of power storages. Electrochemical supercapacitor is one of clean and sustainable candidates of energy storage system, and porous carbons are the most potential candidate as electrode materials for electrochemical supercapacitor because of their large surface areas, high chemical and physical stability, good conductivity, as well as low cost. In this work, we synthesized the mesoporous carbons by using ZnO nanoparticles as sacrificing template via nano-casting synthetic process and natural porous carbon materials. The synthesized porous carbon has a mesoporous structure. Because the surface area and pore size of the synthesized mesoporous carbon are larger than that of the coconuts fiber-derived carbon, the CV plots show that the synthesized mesoporous carbon has a good rectangular shape and a much better performance than that of the coconuts fiber-derived carbon. We also develop an easy way to discriminate how well a supercapacitor works. We applied these porous carbon-based electrodes on both handmade as well as the commercial capacitors and measured their electrical performances. The handmade EDLC is less efficient than the commercial capacitor.
Dependence of Alloy Composition in Color Change of Brass Foil by Oxide Thin Layer Formation
It is known that copper foil undergoes a color change in heating by oxide thin layer formation. Therefore, we focused on the color change by the oxidation of brass foil. Brass foil (Akaguchi (Cu87%Zn13% alloy) and Aoguchi (Cu85%Zn15% alloy)) also undergoes color change by oxidation, and it shows heating time and temperature dependence. Brass foil need longer heating time to appear color change than copper foil, and we can visually confirm that the brass has corrosion resistant. In addition, color change of brass foil depends on the percentage of copper in the brass, and Aoguchi shows rapidly color change in same heating condition. We show that brass has different physical properties than copper, even with a high percentage of copper in brass, and this was verified through comparison using diffusion length and RGB data in Aoguchi and Akaguchi. We demonstrate these colored brass foils are used as art materials, and our results expanded material using possibility of brass foil.