An easy-to-prepare, reusable and versatile catalyst consisting of oxidised copper nanoparticles on activated carbon has been fully characterised and found to effectively promote the multicomponent synthesis of 1,2,3-triazoles from organic halides, diazonium salts, and aromatic amines in water at a low copper loading.
Copper-Catalyzed Decarboxylative Cycloaddition of Propiolic Acids, Azides, and Arylboronic Acids: Construction of Fully Substituted 1,2,3-Triazoles
作者:Xiang-Xiang Wang、Yangchun Xin、Yi Li、Wen-Jin Xia、Bin Zhou、Rui-Rong Ye、Ya-Min Li
DOI:10.1021/acs.joc.9b03285
日期:2020.3.6
A copper-catalyzed decarboxylative cycloaddition of propiolic acids, azides, and arylboronicacids is described. The present reaction provides an efficient and convenient method for the synthesis of various fully substituted 1,2,3-triazoles from readily available starting materials. A possible mechanism is proposed.
Organic synthesis via magnetic attraction: benign and sustainable protocols using magnetic nanoferrites
作者:R. B. Nasir Baig、Rajender S. Varma
DOI:10.1039/c2gc36455g
日期:——
Magnetic nano-catalysts have been prepared using simple modification of iron ferrites. The nm size range of these particles facilitates the catalysis process, as an increased surface area is available for the reaction; the easy separation of the catalysts by an external magnet and their recovery and reuse are additional beneficial attributes. Glutathione bearing nano-ferrites have been used as organocatalysts for the Paal–Knorr reaction and homocoupling of boronic acids. Nanoferrites, post-synthetically modified by ligands, were used to immobilize nanometals (Cu, Pd, Ru, etc.) which enabled the development of efficient, sustainable and green procedures for azide–alkynes-cycloaddition (AAC) reactions, C–S coupling, O-allylation of phenol, Heck-type reactions and hydration of nitriles.
three‐component reaction to synthesize 1,4,5‐trisubstituted 1,2,3‐triazoles from readily available building blocks, such as aldehydes, nitroalkanes, and organic azides, is described. The process is enabled by an organocatalyzed Knoevenagelcondensation of the formyl group with the nitro compound, which is followed by the 1,3‐dipolar cycloaddition of the azide to the activated alkene. The reaction features an excellent