| Revista: | Quimica nova |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000198553 |
| ISSN: | 0100-4042 |
| Autores: | Cesarin-Sobrinho, Dari1 Netto-Ferreira, Jose Carlos Braz-Filho, Raimundo |
| Instituciones: | 1Universidade Federal Rural do Rio de Janeiro, Departamento de Quimica, Seropedica, Rio de Janeiro. Brasil 2Universidade Estadual do Norte Fluminense Darcy Ribeiro, Setor de Quimica de Produtos Naturais, Campos dos Goytacazes, Rio de Janeiro. Brasil |
| Año: | 2001 |
| Periodo: | Sep-Oct |
| Volumen: | 24 |
| Número: | 5 |
| Paginación: | 604-611 |
| País: | Brasil |
| Idioma: | Portugués |
| Tipo de documento: | Artículo |
| Enfoque: | Experimental, descriptivo |
| Resumen en inglés | Chalcone (1) and its fluorinated derivatives 2-4, as well as their cyclic analogues 5-10, were synthesized through an aldol condensation reaction between the corresponding ketone and aldehyde. These compounds were characterized by IR, EIMS and 1H and 13C NMR spectral data. Modern NMR techniques allowed us to conclude that the compounds obtained show E configuration. These techniques were also employed to investigate the equilibrium involving the s-cis and s-trans conformations of 1-4, with this equilibrium being dependent on the fluorine substitution on both aromatic rings, A or B. IR studies indicated that the yield of the s-cis conformation in the fluorinated derivatives is 57.4±1.4; 88.1±0.4 and 66.4±0.7%, for 2, 3 and 4, respectively, based on previous 1H NMR calculations for chalcone. Theoretical calculations, using the MMX method, were employed to justify the variation of chemical shifts for the fluorinated derivatives and cyclic analogues. These chemical shifts are consequence of the anisotropic effect showed by the carbonyl group on these compounds |
| Disciplinas: | Química |
| Palabras clave: | Química analítica, Química orgánica, Flúor, Chalconas, Condensación aldólica, Equilibrio conformacional, Efecto anisotrópico |
| Keyword: | Chemistry, Analytical chemistry, Organic chemistry, Fluoride, Chalcones, Aldol condensation, Conformational equilibrium, Anisotropic affect |
| Texto completo: | Texto completo (Ver HTML) |
