Mild and selective α-fluorination of carbonyl compounds (ketones, 1,3-diketones, β-ketoesters, α-nitroketones, and β-ketonitriles) with Selectfluor (F-TEDA-BF4) in imidazolium ILs [BMIM/PF6 or BMIM/NTf2] with Brønsted-acidic IL [PMIM(SO3H)/OTf] as promoter
摘要:
Structurally diverse ketones, 1,3-diketones, and beta-ketoesters, were selectively monofluorinated with Selectfluor (F-TEDA-BF4) (1 equiv) in [BMIM][PF6] as solvent and [PMIM(SO3H)][OTf] as promoter under mild conditions. In selected cases, the monofluorinated products were transformed to the gem-difluoro derivatives by employing an additional equivalent of Selectfluor, and gem-difluoro-derivatives were synthesized directly from the substrates by employing 2 equiv of Selectfluor. The method was extended to monofluorination of representative alpha-nitroketones and beta-ketonitriles using [BMIM][NTf2] without the need for promoters. The described method offers the added advantage of recycling and reuse of the IL solvent.
partly with water. Ionic liquids with the ethyl substituent on the cation [HEIM][Tf2N] show higher solubility in 1-octanol in comparison with the methyl substituent. After the synthesis, the characterization and purity of the compounds were obtained by nuclearmagneticresonance (NMR), elemental analysis, water content (Fischer method), and differential scanning microcalorimetry (DSC). From DSC, the melting
Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> and copper sulfide composite nanofluids with a hierarchical structure for sustainable and efficient solar light–thermal conversion
characteristics. Among various solar energy applications, solar thermal conversion has emerged as one of the most promising and straightforward methods. As a new type of photothermal material, MXene has been widely studied, but its low layer roughness and high reflection coefficient result in weak light–thermal conversion performance. In this work, we prepared nanofluids (hereafter named “Ti3C2Tx/FCuS-IL”
近年来,太阳能因其清洁、丰富、可再生等特点而受到广泛关注。在各种太阳能应用中,太阳能热转换已成为最有前途和最简单的方法之一。MXene作为一种新型光热材料已被广泛研究,但其低层粗糙度和高反射系数导致其光热转换性能较弱。在这项工作中,我们利用聚多巴胺修饰的Ti 3 之间的静电相互作用制备了用于光热转换的纳米流体(以下称为“Ti 3 C 2 T x /FCuS-IL”和“Ti 3 C 2 T x /HCuS-IL”) C 2T x和 CuS 复合光热材料(Ti 3 C 2 T x /FCuS 和 Ti 3 C 2 T x /HCuS)与 [EBIM]NTf 2。花状和空心CuS的引入可以有效提高Ti 3 C 2 T x的表面粗糙度,从而增加材料的受光面积。研究表明,离子液体(IL)可以作为有效的集热工作流体,扩大纳米流体的液体路径范围并为其提供增强的热稳定性。此外,离子液体表现出较低的粘度,这