Artículos
Título:
Synthesis and thermal reactivity of 2,2-Dioxo-3-Benzyl-7-trifluoromethyl-1H,3H pyrrolo[1,2-c]thiazole
Autor/es:
WALTER JOSÉ PELÁEZ; TERESA M.V.D. PINHO E MELO
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 69 p. 3646 - 3646
Resumen:
he generation and reactivity of 1-benzyl-5-trifluoromethyl-azafulvenium methide are described. Under
microwave induced pyrolysis this intermediate could be trapped by dipolarophiles acting as a 4p as well
as 8p dipole. It was observed that with dimethyl acetylenedicarboxylate the 1,3-dipolar cycloadduct was
the major product whereas with N-substituted maleimides the major product results from the addition
across the 1,7-position. FMO analysis of the cycloadditions corroborated the rationalization of the
observed reactivity. Quantum chemical calculations carried out at the DFT level of theory allowed the
rationalization of the stereoselectivity observed in the cycloaddition of 1-benzyl-5-trifluoromethylazafulvenium
methide with N-substituted maleimides. The study revealed that exo-cycloaddition is the
main reaction path for the 1,7-cycloaddition, while the endo-approach is the main mode of reaction
leading to 1,3-cycloadducts. In addition, under flash vacuum pyrolysis or conve