0000000000002082
AUTHOR
Claudia Della Rosa
Ionic liquids and microwave irradiation as synergistic combination for polar Diels–Alder reactions using properly substituted heterocycles as dienophiles: A DFT study related
For the DA reactions between nitropyrrole derivatives and isoprene, the combination of microwave irradiation and protic ionic liquid, has a notable synergistic effect. DFT calculations suggest that a supplementary energy ranking in the IR region of 1700-1400 cm-1 can favour the structural changes in the reactants to reach the TS. Fil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química; Argentina Fil: Ormachea, Carla. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa F…
Polar Diels–Alder reactions using electrophilic nitrobenzothiophenes. A combined experimental and DFT study
Abstract The reactions between 2- and 3-nitrobenzothiophenes with three dienes of different nucleophilicity, 1-methoxy-3-trimethylsilyloxy-1,3-butadiene, 1-trimethylsilyloxy-1,3-butadiene and isoprene developed in anhydrous benzene and alternative under microwave irradiation with molecular solvents or in free solvent conditions, respectively, for produce dibenzothiophenes permit to conclude that both nitroheterocycles act as electrophile with the cited dienes. In the cases of the dienes 1-methoxy-3-trimethylsilyloxy-1,3-butadiene and 1-trimethylsilyloxy-1,3-butadiene which posses major nucleophilicity the observed product is the normal cycloaddition one. However when the diene is isoprene t…
Experimental and theoretical studies on polar Diels–Alder reactions of 1-nitronaphathalene developed in ionic liquids
The reactions between 1-nitronaphthalene 1 and two nucleophilic dienes, Danishefsky´s diene 2 and 1-trimethylsilyloxy-1,3-butadiene 3, to yield phenanthrenols 7 and 8 developed in protic and aprotic ionic liquids (ILs) with an imidazolium cation base permit to conclude that the reactions occur in better experimental conditions than in molecular solvents. The yields obtained with protic ILs are better than those observed with aprotic ILs. In this sense, the higher yields obtained with aprotic ILs, (working at 60ºC, 48 h) are comparable with the lower yields observed in protic ILs (60 ºC, 24 h). DFT calculations for the reaction of 1-nitronaphthalene 1 with diene 3, in the absence and in the …