Bifunctional acid–base ionic liquid for the one-pot synthesis of fine chemicals: Thioethers, 2H-chromenes and 2H-quinoline derivatives
作者:Maria J. Climent、Sara Iborra、Maria J. Sabater、Juan D. Vidal
DOI:10.1016/j.apcata.2014.05.004
日期:2014.7
A bifunctionalorganocatalyst with ionicliquid properties and with an optimized distancebetween the acid and basic sites efficiently activates electron deficient olefins for 1,4 conjugated addition, which can be incorporated in different one-pot transformations for the preparation of cyclic and acyclic compounds of biological and synthetic interest. More specifically, the catalyst can be successfully
A green metal-free “one-pot” microwave assisted synthesis of 1,4-dihydrochromene triazoles
作者:Tânia M. F. Alves、Guilherme A. M. Jardim、Marco A. B. Ferreira
DOI:10.1039/d1ra01169c
日期:——
The synthesis of several 4-aryl-1,4-dihydrochromene-triazoles was achieved via a metal-free “one-pot” procedure using PEG400 as the sole solvent in an eco-friendly process. Using microwave irradiation, the triazole derivatives were obtained in good yields and short reaction times starting from readily accessible building blocks.
Facile access to 2-aryl-3-nitro-2H-chromenes and 2,3,4-trisubstituted chromanes
作者:Ping-An Wang、Dong-Xu Zhang、Xue-Ying Liu
DOI:10.3998/ark.5550190.p008.801
日期:——
materials, 2-aryl-3-nitro-2H-chromenes were prepared in good yields (up to 83%) through the combination of 30 mol% of pyrrolidine- benzoic acid catalyzed tandem oxa-Michael-Henry reactions in refluxing ethanol. Additionally, the Michael reactions of 2-aryl-3-nitro-2H-chromenes with acetone were also performed by the same catalytic combination in brine to give 2,3,4-trisubstitutedchromanes up to 86%
Molecular diversity of the domino annulation reaction of 2-aryl-3-nitrochromenes with pivaloylacetonitriles
作者:Wang Jiang、Jing Sun、Ru-Zhang Liu、Chao-Guo Yan
DOI:10.1039/c8ob01504j
日期:——
In the presence of triethylamine, the domino annulation reaction of two molecules of pivaloylacetonitrile with one molecule of 2-aryl-3-nitrochromene in tetrahydrofuran resulted in the unprecedented imino-substituted dihydrofuro[2,3-c]chromene derivatives in high yields.
3-Nitrochromenes bearing various substitutents have been prepared by the reaction of substituted salicylaldehydes with nitrostyrenes; some of these compounds have been found to display efficient optical second harmonic generation.