Deep eutectic solvents (Reline) and Gold Nanoparticles Supported on Titanium Oxide (Au–TiO2) as New Catalysts for synthesis some substituted phenyl(substituted-3-phenyloxiran)methanone Enantioselective Peroxidation
作者:Layth Abdullah、shakir Saied、Mohanad Saleh
DOI:10.21608/ejchem.2021.68511.3498
日期:2021.4.12
Background: The eco-friendly power of hydrogen peroxide oxidant produced water that was the only by-product after oxidation. Unfortunately, its oxidation power towards chalcones and chalcones analogs was substantially low, and therefore, it was normally used together with a catalyst or converted to hydroperoxides in order to improve its oxidation power. Objective: This research aimed to study epoxidation chemistry. Hence, hydrogen peroxide was used as a potential oxidant for epoxidation with different techniques and catalysts. Methodology: Advantageous effects of (reline) (derived from two moles of choline chloride and one mole of urea) as a deep eutectic solvent (DES) or the gold (Au) catalyst nanoparticles (NPs) supported on titanium oxide (Au–TiO2) on the chalcone derivatives of peroxidation was studied under several procedure conditions using hydrogen peroxide/sodium bicarbonate to produce novel oxiranes (I-VI). Results and Discussion: Acceptable results were obtained by method (B) using hydrogen peroxide/sodium bicarbonate – (reline) mixture, which gave 87- 90% peroxidation results in a short time (4 h) in comparison with less than 86% and 24 h of the conventional method (A), while using the Au NPs supported on titanium oxide (Au–TiO2); that is, Method (C) gave the best percentage yield of 90-95 % and time (about 2 h), which is about half of that of (Reline) mixture. Such a condition may be due to high activation of hydrogen peroxide by Au and titanium oxide nanoparticles and low viscosity of the reaction mixture. Conclusions: The chalcones epoxidations would convince chemists that using the deep eutectic solvent (Reline) and the Au-supported on titanium oxide NPs for catalysing these reactions are techniques of great importance in various branches of oxidation.
背景:过氧化氢氧化剂具有环保功能,氧化后产生的唯一副产品就是水。遗憾的是,它对查耳酮和查耳酮类似物的氧化能力很低,因此,它通常与催化剂一起使用或转化为氢过氧化物,以提高其氧化能力。 研究目的本研究旨在研究环氧化化学。因此,采用不同的技术和催化剂,将过氧化氢作为环氧化的潜在氧化剂。 方法:使用过氧化氢/碳酸氢钠,研究了(reline)(由两摩尔氯化胆碱和一摩尔尿素制得)作为深共晶溶剂(DES)或氧化钛(Au-TiO2)上支持的金(Au)催化剂纳米颗粒(NPs)在几种程序条件下对查尔酮衍生物过氧化反应的有利影响,以生成新型环氧乙烷(I-VI)。 结果与讨论:使用过氧化氢/碳酸氢钠-(Reline)混合物的方法(B)获得了可接受的结果,与传统方法(A)的不到 86% 的过氧化率和 24 小时相比,该方法在短时间(4 小时)内获得了 87-90% 的过氧化率,而使用氧化钛(Au-TiO2)上支持的 Au NPs 的方法(C)则获得了 90-95% 的最佳产率和时间(约 2 小时),约为(Reline)混合物的一半。这种情况可能是由于金和氧化钛纳米颗粒对过氧化氢的活化程度高,以及反应混合物的粘度低。 结论查尔酮环氧化反应让化学家们相信,使用深共晶溶剂(Reline)和氧化钛纳米颗粒上的金支持催化这些反应是在各种氧化分支中非常重要的技术。