The nitroxyl radical 3‐oxo‐9‐azabicyclo [3.3.1]nonane‐N‐oxyl (3‐oxo‐ABNO) has been prepared using a simple protocol. This organocatalyst is found to be an efficient catalyst for the aerobic oxidation of a wide variety of alcohols under metal‐free conditions. In addition, the preparation and characterization of a supported version of 3‐oxo‐ABNO on ordered mesoporous silica SBA‐15 (SABNO) is described
Aerobic Oxidation of Alcohols Catalyzed by <i>in Situ</i> Generated Gold Nanoparticles inside the Channels of Periodic Mesoporous Organosilica with Ionic Liquid Framework
In situ generated gold nanoparticles inside the nanospaces of periodic mesoporous organosilica with an imidazolium framework ([email protected]) were found to be highly active, selective, and reusable catalysts for the aerobicoxidation of activated and nonactivated alcohols under mild reaction conditions. The catalyst was characterized by nitrogen adsorption–desorption measurement, thermogravimetric
发现具有咪唑骨架的周期性介孔有机硅纳米空间内的原位生成的金纳米粒子是高活性,选择性和可重复使用的催化剂,可在温和的反应条件下对活化和非活化醇进行好氧氧化。该催化剂的特征在于氮吸附-解吸测量,热重分析(TGA),透射电子显微镜(TEM),元素分析(EA),漫反射红外傅里叶变换光谱(DRIFT),X射线光电子能谱(XPS)和电感耦合等离子体原子发射光谱法(ICP-AES)。在Cs 2 CO 3(35°C)或K 2的存在下,该催化剂表现出优异的催化活性。一氧化碳3(60°C)作为反应基础在甲苯中作为反应溶剂。在两种反应条件下,各种类型的醇(最多35个实例),包括活化的苄基,伯和仲脂族,杂环和具有挑战性的环状脂族醇,都以良好的产率和选择性很好地转化为预期的羰基化合物。还回收了催化剂并将其再利用至少七个反应循环。来自三个独立浸出测试的数据表明,浸出金颗粒的量可以忽略不计(<0.2 ppm)。据信,桥
Synthesis of Highly Substituted γ-Butyrolactones by a Gold-Catalyzed Cascade Reaction of Benzyl Esters
作者:Maria Camila Blanco Jaimes、Alexander Ahrens、Daniel Pflästerer、Matthias Rudolph、A. Stephen K. Hashmi
DOI:10.1002/chem.201402524
日期:2015.1.2
3‐butynoic acids in a gold‐catalyzed cyclization/rearrangement cascadereaction provided 3‐propargyl γ‐butyrolactones with the alkene and the carbonyl group not being conjugated. Crossover experiments showed that the formation of the new CC bond is an intermolecular process. Initially propargylic–benzylic esters were used, but alkyl‐substituted benzylic esters worked equally well. In the case of the propargylic–benzylic
A Highly Recyclable Magnetic Core‐Shell Nanoparticle‐Supported TEMPO catalyst for Efficient Metal‐ and Halogen‐Free Aerobic Oxidation of Alcohols in Water
作者:Babak Karimi、Elham Farhangi
DOI:10.1002/chem.201100047
日期:2011.5.23
the tempo! A new, stable, TEMPO‐based organocatalyst, supported on magnetic iron nanoparticles, provides a highlyefficient heterogeneous catalyst 1 for the metal‐ and halogen‐free aerobicoxidation of a wide range of primary, secondary, allylic, and even sterically hindered alcohols in water. After use, the catalyst was magnetically separated (see image) and reused for 20 consecutive rounds of reaction
Gold Nanoparticles Supported on the Periodic Mesoporous Organosilicas as Efficient and Reusable Catalyst for Room Temperature Aerobic Oxidation of Alcohols
作者:Babak Karimi、Farhad Kabiri Esfahani
DOI:10.1002/adsc.201100802
日期:2012.5.7
Gold nanoparticles supported on the channels of a bifunctional periodic mesoporous organosilica, were found to be a highlyefficientcatalyst system for the aerobicoxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature. The catalyst showed no significant loss of efficiency for the aerobicoxidation of benzyl alcohol to give benzaldehyde after 7 reaction