Cu/SBA-15 is an Efficient Solvent-Free and Acid-Free Catalyst for the Rearrangement of Benzaldoxime into Benzamide

Abstract

Cu/SBA-15 catalysts with various Cu loadings in the range of 5-20 wt% were prepared by an impregnation method and characterized by N 2 adsorption, X-ray diffraction, temperature programmed reduction and X-Ray photoelectron spectroscopic techniques. Cu/SBA-15 catalysts are found to be highly active and selective for the Beckmann rearrangement of benzaldoxime into benzamide under solvent-free and acid-free conditions.

Copper(II) Acetate-Catalysed Conversion of Aldoximes to Amides under Mild Conditions

“…We noted that the addition of nitriles in the rhodium-catalysed conversion of aldoximes to amides had been reported to have a significant rate acceleration effect. 8,14 Thus, we thought that the reaction mechanism is likely to be similar to that reported in the literature, 8,14,15 proceeding via a metal-catalysed route rather than the conventional Beckmann rearrangement. As shown in Scheme 1, benzaldoxime reacts with acetonitrile in the presence of copper(II) acetate to form acetamide and a benzonitrilecopper complex, which further complexes with benzaldoxime and transforms into benzamide.…”

“…Catalysts reported recently include those containing Rh, 5 Ru, 6 Ag/Au 7 and Cu. [8][9][10][11][12][13] We planned to use a copper catalyst in our work and we noted that some Cu-catalysed reactions usually proceeded at a relatively high temperature 8,13 or the reaction time was relatively long. [9][10][11] In this paper, we report the development of a mild and relatively rapid method for the conversion of aldoximes to amides by the combined use of copper(II) acetate and acetonitrile in ethanol.…”

Use of CuO encapsulated in mesoporous silica SBA-15 as a recycled catalyst for allylic C–H bond oxidation of cyclic olefins at room temperature

“…Among them, SBA-15 has some advantages such as hexagonally arrayed channels and narrow pore size distribution so that it has attracted great attention. [51][52][53] Immobilization of metal NPs within a silica scaffold prevents agglomeration and surface fouling, and aids in NP recovery and recycling. [54][55][56][57] In our previous work, we reported the effect of some additives such activated silica gel, mesoporous MCM-41, SBA-15 silica, nanocrystalline MgO, CuO and TiO 2 on this reaction and SBA-15 was shown better results than others.…”

Recent Progress in Beckmann Rearrangement

“…铜催化的贝克曼重排已被系统的研究. Burri 课题 组 [28] 通过制备 Cu/SBA-15 催化剂, 在无溶剂中性条件下 实现了醛肟向酰胺的转变. Mondal 课题组 [29] 发展了五 水硫酸铜催化的醛肟转化为伯酰胺的新方法.…”