6533b7d8fe1ef96bd126a304

RESEARCH PRODUCT

Understanding the participation of 3-nitropyridine in polar Diels–Alder reactions. A DFT study

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The reactivity of 3-nitropyridine acting as an electrophilic dienophile in polar Diels-Alder (P-DA) reactions toward three different dienes of increased nucleophilicity has been theoretically studied using DFT methods at the MPWB1K/6-31G(d) level. It has been observed that this aromatic heterocyclic system suffers cycloaddition reactions yielding isoquinoline derivatives. The present DFT study establishes that while the P-DA reactions with isoprene and 1-methoxy-1,3-butadiene take place through a two-stage one-step mechanism, the use of the strong nucleophilic Danishefsky's diene changes the mechanism to a two-step one with formation of a zwitterionic intermediate. These P-DA reactions are completely regioselective allowing the formation of a unique substituted isoquinoline. Analysis of the DFT reactivity indices at the ground state of the reagents correctly explains the reactivity and regioselectivity for these P-DA reactions. Fil: Ormachea, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina Fil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina Fil: Kneeteman, Maria Nelida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina Fil: Domingo, Luis R.. Universidad de Valencia; España