Synthesis of some benzimidazole derivatives via condensation reaction of o-phenylenediamine derivatives with aromatic aldehydes or orthoesters under solvent-free conditions over nano-Ni(II)/Y zeolite as a heterogeneous catalyst is reported. Some advantages of this green method are easy purification, environmentally friendly conditions, low catalyst loadings, and nontoxic nature.
Graphite-Supported Gold Nanoparticles as Efficient Catalyst for Aerobic Oxidation of Benzylic Amines to Imines and<i>N</i>-Substituted 1,2,3,4-Tetrahydroisoquinolines to Amides: Synthetic Applications and Mechanistic Study
作者:Man-Ho So、Yungen Liu、Chi-Ming Ho、Chi-Ming Che
DOI:10.1002/asia.200900261
日期:2009.10.5
of N‐substituted 1,2,3,4‐tetrahydroisoquinolines in the presence of aqueous NaHCO3 solution gave the corresponding amides in good yields (83–93 %) with high selectivity (up to amide/enamide=93:4) (6 examples). The same protocol can be applied to the synthesis of benzimidazoles from the reaction of o‐phenylenediamines with benzaldehydes under aerobic conditions (8 examples). By simple centrifugation
使用氧气作为末端氧化剂对胺进行选择性氧化是绿色化学中的重要领域。在这项工作中,我们描述了使用石墨负载的金纳米颗粒(AuNPs / C)催化环状和非环状苄胺的好氧氧化为相应的亚胺,具有中等至优异的底物转化率(43-100%)和产品收率(66–99%)(19个例子)。在NaHCO 3水溶液存在下,对N-取代的1,2,3,4-四氢异喹啉进行氧化,得到的酰胺产率高(83-93%),选择性高(酰胺/酰胺= 93:4)( 6个示例)。相同的协议可以从反应被施加到苯并咪唑的合成Ò在好氧条件下将苯二胺与苯甲醛一起使用(8个例子)。通过简单的离心,可以回收AuNPs / C并重复使用十次,以将二苄基胺氧化为N-亚苄基(苯基)甲胺,而不会显着降低催化活性和选择性。可以将协议“ AuNPs / C + O 2 ”调整为克级,通过氧化10 g 1,2,3,4-可以得到8.9 g(84%分离出的产率)3,4-二氢异
Fe3O4@SiO2/collagen: An efficient magnetic nanocatalyst for the synthesis of benzimidazole and benzothiazole derivatives
作者:Hossein Ghafuri、Elahe Esmaili、Majid Talebi
DOI:10.1016/j.crci.2016.05.003
日期:2016.8
Résumé In this project, Fe3O4@SiO2 was synthesized and combined with collagen for the preparation of Fe3O4@SiO2/collagen. It was characterized by FT-IR, 1H NMR, VSM, XRD, EDX, SEM and TEM. This nanocatalyst has some interesting advantages such as facile synthetic procedure, high catalytic activity, easy separation and acceptable reusability. It was applied as an efficient nanocatalyst in the synthesis of benzimidazole and benzothiazole derivatives. This method offers several advantages including high yields, short reaction times, easy workup process and environmentally benign reaction conditions.
Reusable Porphyrinatoiron(III) Complex Supported on Activated Silica as an Efficient Heterogeneous Catalyst for a Facile, One-Pot, Selective Synthesis of 2-Arylbenzimidazole Derivatives in the Presence of Atmospheric Air as a “Green” Oxidant at Ambient Temperature
An efficient and highly selective synthesis of 2-arylbenzimidazoles by condensation of a wide range of aryl aldehydes bearing electron-donating or -withdrawing substituents and phenylenediamines in a single pot using a catalytic amount of (meso-tetrakis(o-chlorophenyl)porphyrinato)iron(III) chloride (5 mol-%) in excellent isolated yields is described. The reactions were performed in the presence of
The magnetic nanoparticles-supported tungstosilicic acid (TSAMNP) was found to be a highly efficient solid acid for the synthesis of benzoazoles in water. TSAMNP catalyst was achieved by the immobilization of tungstosilicic acid [H4(W12SiO40)] species on the silica core–shell magnetic nanoparticles (Fe3O4@SiO2). A variety of aldehydes were successfully condensed with 1,2-diaminobenzene, 2-aminophenol and 2-aminothiophenol in water as a green solvent to synthesize benzoazoles in good-to-excellent yields. TSAMNP catalyst was easily separated from the reaction mixture and reused several times without any loss of efficiency.