Unmodified Fe3O4 nanostructure promoted with external magnetic field: safe, magnetically recoverable, and efficient nanocatalyst for N- and C-alkylation reactions in green conditions
high catalytic activity and stability in N- and C-alkylationreactions. A diverse range of N- and C-alkylation products were obtained in moderate to high yield under green and mild conditions in air. Also the N- and C-alkylation products can be obtained with different selectivity and yield by exposure reactions with EMF. Results of alkylation reactions showed that the presence of Fe(II) and Fe(III)
过渡金属化合物已作为有机反应的合适催化剂出现。磁性化合物如柔软的路易斯酸可用作有机反应的催化剂。在该报告中,在没有任何保护剂的外部磁场(EMF)下,从Fe 2+和Fe 3+盐获得了Fe 3 O 4纳米结构。X射线光电子能谱,扫描电子显微镜和能量色散X射线能谱工具用于表征这些磁性化合物。二维(二维,它在二维中显示纳米尺寸,纳米棒结构)Fe 3 O 4该化合物在N和C烷基化反应中显示出高催化活性和稳定性。在绿色和温和的条件下,在空气中以中等至高收率获得了各种N-和C-烷基化产物。通过与EMF的暴露反应,也可以以不同的选择性和产率获得N-和C-烷基化产物。烷基化反应的结果表明,磁性催化剂表面(磁性化合物的相结构)上存在Fe(II)和Fe(III)物种是非常廉价的活性位点所必需的。而且,磁性催化剂的形态对其催化性能有影响。反应后,使用外部磁体可以轻松实现催化剂/产物的分离,并且可以回收超过95%的催化剂。
Metal-Free C–O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
作者:Luis Bering、Kirujan Jeyakumar、Andrey P. Antonchick
DOI:10.1021/acs.orglett.8b01495
日期:2018.7.6
conditions enabled a catalytic and metal-free Friedel–Craftsalkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel–Crafts reaction.
Different ionicliquids (ILs) with SO 3 H as functional group were achieved by combining SO 3 H-functionalized organic cations and polyoxometalates (POM). The obtained salts were characterized and their catalytic activities investigated in C C coupling between benzhydrol and aromatic compounds at neat conditions, including the effect of organic cations, influence of POMs, optimization of reaction conditions
摘要 通过将SO 3 H 官能化的有机阳离子和多金属氧酸盐(POM) 结合,制备了以SO 3 H 为官能团的不同离子液体(ILs)。对所得盐进行表征,并研究了它们在纯条件下二苯甲醇和芳香族化合物的 CC 偶联中的催化活性,包括有机阳离子的影响、POM 的影响、反应条件的优化和催化剂的可重复使用性。此外,至少四次研究了离子液体作为非均相催化剂的回收率、可重复使用性和活性。
Superacid BF<sub>3</sub>–H<sub>2</sub>O promoted benzylation of arenes with benzyl alcohols and acetates initiated by trace water
An efficient in situ prepared superacid BF3–H2O promoted benzylation of arenes using benzyl alcohols and acetates achieves various diarylalkanes.
一种高效的原位制备的超强酸BF3-H2O促进的芳烃苄基化反应,使用苄醇和醋酸酯制备各种二芳基烷烃。
Cascade Reductive Friedel–Crafts Alkylation Catalyzed by Robust Iridium(III) Hydride Complexes Containing a Protic Triazolylidene Ligand
作者:Iryna D. Alshakova、Martin Albrecht
DOI:10.1021/acscatal.1c00740
日期:2021.8.6
multiple single-step reactions, in series or in a modular fashion, with laborious purification and potentially unstable intermediates. Cascade processes offer attractive synthetic remediation as they reduce time, energy, and waste associated with multistep syntheses. For example, triarylmethanes are traditionally prepared via several synthetic steps, and only a handful of cascade routes are known with limitations