59566-50-6Relevant academic research and scientific papers
Exploring the acidic catalytic role of differently structured deep eutectic solvents in the aza-Michael addition of amines to 2-vinylpiridine
Ballarotto, Marco,Cappellini, Federico,Del Giacco, Tiziana,Di Profio, Pietro,Germani, Raimondo,Maestri, Riccardo,Tiecco, Matteo
, (2020/08/26)
Abstract: The search for innovative and green reaction media is a prominent topic in the recent research in chemistry. Deep Eutectic Solvents (DESs) are currently gaining relevance in this field thanks to their unique properties in terms of their “greenness” as well as in terms of their catalytic properties. In this work we developed an efficient protocol for the conjugate aza-Michael addition of amines to 2-vinylpyridine using 14 differently structured acid DESs as both reaction media and catalysts, so preventing the use of other acid additives. The results are influenced by the acidity of the components of the DESs, showing the best results with weak acids in the DESs components, with isolated yields up to 86%. The aza-Michael reaction is a widely used synthetic route for the C–N bond formation in organic synthesis. In particular, the addition of amines to 2-vinylpyridine is used for the realization of pharmaceutically relevant compounds with anticancer, antiarrhythmic, and analgesic properties. Comparing the results with the ones observed in literature for the same reaction, this procedure revealed to be a convenient and efficient method for this relevant transformation. Graphic abstract: [Figure not available: see fulltext.]
Aza-Michael-type addition reaction catalysed by a supported ionic liquid phase incorporating an anionic heteropoly acid
Ghasemi, Mohammad Hadi,Kowsari, Elaheh,Shafiee, Abbas
, p. 1150 - 1153 (2016/03/09)
In this work, we have obtained substituted amines under mild conditions in good yields using the Aza-Michael-type addition of various amines to vinyl compounds catalysed by a supported ionic liquid incorporating an anionic heteropoly acid. Different catalysts, including Lewis acids, Br?nsted acids and heteropoly acids were investigated in which heteropoly acids having dual Br?nsted and Lewis acid characteristics were excellent catalysts. The ionic liquid incorporating a polytungstate anion supported on magnetic diatomaceous earth as a magnetically separable heterogeneous catalyst offered the best results in terms of yield. The solid nanocatalyst was easily removed with a magnet.
Lewis acid activation of pyridines for nucleophilic aromatic substitution and conjugate addition
Abou-Shehada, Sarah,Teasdale, Matthew C.,Bull, Steven D.,Wade, Charles E.,Williams, Jonathan M. J.
, p. 1083 - 1087 (2015/03/30)
A clean, mild and sustainable method for the functionalization of pyridines and their analogues is reported. A zinc-based Lewis acid is used to activate pyridine and its analogues towards nucleophilic aromatic substitution, conjugate addition, and cyclization reactions by binding to the nitrogen on the pyridine ring and activating the pyridine ring core towards further functionalization.
Anti-Markonikov reactions, 6. Rhodium-catalyzed amination of vinylpyridines: Hydroamination versus oxidative amination
Beller, Matthias,Trauthwein, Harald,Eichberger, Martin,Breindl, Claudia,Mueller, Thomas E.
, p. 1121 - 1132 (2007/10/03)
Cationic rhodium complexes catalyze the amination of 2- and 4- vinylpyridine with secondary amines. Depending on the substrate and the reaction conditions either oxidative amination to yield the corresponding enamines 1a-8a or hydroamination to give 2-aminoethylpyridines 1b-8b occurs. In all cases products with anti-Markovnikov regioselectivity are obtained. For mechanistic studies novel cationic complexes of rhodium(I)-containing cyclooctadiene and vinylpyridine 12 as well as complexes containing cyclooctadiene, vinylpyridine, and morpholine 13 were prepared and characterized by NMR spectroscopy and X-ray diffraction analysis.
SYNTHESIS OF FUNCTIONALLY SUBSTITUTED PYRIDINES AND DIPYRIDYL-SUBSTITUTED COMPOUNDS WITH THE AID OF LOW-VALENCE COMPOLEXES
Selimov, F. A.,Khafizov, V. R.,Dzhemilev, U. M.
, p. 290 - 295 (2007/10/02)
The possibility of the preparation of oxygen, nitrogen, and sulfur-containing pyridines and dipyridyl-substituted compounds by the cyclocotrimerization of substituted propionitriles with acetylene under the influence of a Co(2-ethylhexanoate)2-Al(C2H5)3 catalyst was demonstrated.It was established that the nature of the heteroatom in substituted propionitriles has virtually no effect on the direction of the reaction.
