Nano-sized NiLa2O4 spinel–NaBH4-mediated reduction of imines to secondary amines
摘要:
Nano-sized NiLa2O4 spinel was produced by thermal decomposition of Ni-La compounds via a sol-gel method. The well-crystallized spinel structure was formed after calcination at 750 degrees C. The physicochemical properties of the spinel were investigated using differential thermal analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and particle size distribution analysis. The results show that the nanoparticles have regular shapes with well-defined crystal faces and consist of uniform quasi-spherical crystallites of average size 40 nm. The refined unit cell parameters are a = 3.861205 angstrom and c = 12.6793 angstrom. This new nano-sized NiLa2O4 spinel is an efficient heterogeneous catalyst for the selective conversion of imines to the corresponding secondary amines in the presence of NaBH4 as a reducing agent, in good to excellent yields. All the reactions were completely chemoselective at room temperature and had relatively short reaction times. Secondary amines with different aryl groups, including those bearing electron-withdrawing or electron-donating groups, were obtained under the optimum reaction conditions. The catalyst was readily recovered and was recycled four times with no significant loss of catalytic activity. (C) 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
Here we designed and synthesized a NN–CoII bidentate complex and efficiently used it for general and expedient amination of alcohols under benign, solventlessconditions. Both primary (including unactivated aliphatic) alcohols and sterically hindered secondary alcohols exhibited very good reactivity and provided diverse amines with good substrate scope (88 examples; up to 95% yields) and excellent
Verbindungen der Formel(I)
worin R₁ für Wasserstoff, Methyl oder Halogen steht, n 2 oder 3 bedeutet und R für C₁-C₆-Alkyl, Benzyl, 2-Tetrahydrofuranyl, 2-Tetrahydropyranyl, C₁-C₆-Alkoxycarbonyl, Phenoxycarbonyl oder Benzyloxycarbonyl steht, oder, falls zwei der Substituenten OR in ortho-Stellung zueinander stehen, zwei Reste R zusammen eine Ethylengruppe, die gegebenenfalls durch bis zu vier C₁-C₆-Alkylgruppen substituiert ist, oder eine C₂-C₆-Alkylidengruppe bilden,
können, gegebenenfalls in Gegenwart von anderen ungesättigten Comonomeren, zu Polymeren mit einem Molekulargewicht Mw von 10³ bis 10⁶ polymerisiert werden, die sich zur Herstellung von Positiv-Photoresists mit hohem Auflösungsvermögen und sehr gutem Kontrast eignen.
Magnetically Recyclable Borane Lewis Acid Catalyst for Hydrosilylation of Imines and Reductive Amination of Carbonyls
作者:Vitthal B. Saptal、Prabodh Ranjan、Radek Zbořil、Marek Nowicki、Jędrzej Walkowiak
DOI:10.1002/cssc.202400058
日期:2024.8.12
Heterogenization of boron Lewis's acid catalyst has been achieved on the surface of allyl functionalized Fe3O4 using Piers’ borane. The resulting catalyst offered an excellent activity and recyclability for the hydrosilylation reaction of imines and reductiveamination reaction to access the wide range of amines at mild reaction conditions.
使用Piers硼烷在烯丙基官能化的Fe 3 O 4表面上实现了硼Lewis酸催化剂的多相化。所得催化剂为亚胺氢化硅烷化反应和还原胺化反应提供了优异的活性和可回收性,可在温和的反应条件下获得多种胺。
METHOD OF PREPARING RESIN COMPOSITION FOR ARTIFICIAL MARBLE CHIP HAVING HIGH SPECIFIC GRAVITY AND HIGH INDEX OF REFRACTION