Search Results for: Diels Alder

Author: López, I.; Silvero, G.; Arévalo, M.J.; Babiano, R.; Palacios, J. C.; Bravo, J.L. Description: This manuscript explores in detail the combined effect of solid supports or microwave irradiation in ionic liquids on a series of Diels-Alder reactions involving 1,3-cyclopentadiene and numerous dienophiles. Subject Headings: Diels-Alder; Solid supports; Ionic liquids; Microwaves; Montmorillonite Keywords: Enhanced Diels-Alder reactions: on the role of mineral catalysts and microwave irradiation in ionic liquids as recyclable media Publication year: 2007 Journal or book title: Tetrahedron Volume: 63 Issue: 13 Pages: 2901-2906 Find the full text : https://www.sciencedirect.com/science/article/pii/S0040402007000877 Find…

Author: Nicolaou, K. C.; Snyder, Scott A.; Montagnon, Tamsyn; Vassilikogiannakis, Georgios Description: The Diels-Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which, arguably, has yet to be eclipsed by any other transformation in the current synthetic repertoire. With myriad applications of this magnificent pericyclic reaction, often as a crucial element in elegant and programmed cascade sequences facilitating complex molecule construction, the Diels-Alder cycloaddition has afforded numerous and unparalleled solutions to a diverse range of synthetic puzzles…

Author: Kotteritzsch, Julia; Stumpf, Steffi; Hoeppener, Stephanie; Vitz, Juergen; Hager, Martin D.; Schubert, Ulrich S. Description: Terpolymers containing functional moieties for reversible crosslinking by DA reaction are synthesized for application as self-healing coatings. The polymers are based on a methacrylate backbone containing furan as well as maleimide units in the side chains. No additional crosslinker is required to obtain a self-healing polymeric material. After damage, the material can be heated to a temperature at which the retro-DA reaction takes place. Subsequent cooling to room temperature leads to a healing of…

Author: Islas-Jacome, Alejandro; Gonzalez-Zamora, Eduardo; Gamez-Montano, Roci­o Description: A series of tetrahydroisoquinolin-pyrrolopyridinones were prepared from an easily accessible aldehyde, a commercially available amine, a readily isolable isonitrile, and maleic anhydride via a triple process: Ugi-3CR-aza Diels-Alder/S-oxidation/Pummerer. The combination of a multicomponent Ugi-type reaction with other post-functionalization processes provides a powerful tool for the preparation of fused polyheterocyclic compounds. Subject headings: Microwave-assisted synthesis; Tetrahydroisoquinolin-pyrrolopyridinones; Ugi-3CR; Aza Diels-Alder cycloaddition; S-oxidation; Pummerer cyclization Publication year: 2011 Journal or book title: Tetrahedron Letters Volume: 52 Issue: 41 Pages: 5245-5248 Find the full text: https://www.sciencedirect.com/science/article/pii/S004040391101272X…

Author: Zhang, Ze; Peng, Zhi-Wei; Hao, Ming-Feng; Gao, Jian-Gang Description: Under mechanochemical milling conditions, Diels-­Alder cycloaddition of cyclopentadiene with maleic anhydride and maleimide derivatives proceeded very smoothly, affording endo-norbornenes exclusively in quantitative yield. All the transformations were accomplished at room temperature without using any catalyst or organic solvent, thus the workup and purification procedure is very simple. Control experiments on traditional and other tentative conditions were also investigated. Subject headings: Norbornenes; Mechanochemical milling; Solvent-free; Cyclopentadiene; Diels-Alder reaction Publication year: 2010 Journal or book title: Synlett Issue: 19 Pages: 2895-2898 Find…

Author: Amancha, Prashanth K.; Lai, Yi-Chun; Chen, I. Chia; Liu, Hsing-Jang; Zhu, Jia-Liang Description: The Diels-Alder reactions of a variety of acyclic a-cyano a,B-unsaturated ketones have been investigated. With the assistance of boron trichloride, these compounds were found to undergo the cycloaddition readily with dienes to give the corresponding adducts in good to high yields. In addition, some could be further subjected to the reductive alkylation reactions using lithium naphthalenide (LN) and an appropriate alkylating agent, thus allowing for the generation of highly substituted cyclohexenes with the replacement of the…

Author: Victoria Gómez, M.; Aranda, A.I.; Moreno, A.; Cossío, F.P.; de Cózar, A.; Díaz-Ortiz, Á.; de la Hoz, A.; Prieto, P. Description: Diels-Alder cycloaddition of 3-nitro-1-(p-toluenesulfonyl)indole 1 with dienes 2-6 under microwave irradiation in solvent-free conditions gave carbazole derivatives after elimination of the nitro group and in situ aromatization. While 3-nitro-1-(p-toluenesulfonyl)pyrrole 11 afforded indole derivatives, 4-nitro-1-(p-toluenesulfonyl)pyrazole 13 with cyclohexadiene 2 did not afford the expected cycloadduct but instead gave 1-cyclohexen-2-ylpyrazole 16. This process occurred by hydrolysis of the 1-(p-toluenesulfonyl) group, protonation of the diene and nucleophilic addition of the pyrazolate…