RESUMEN
Two cyanoimidazopyridine-based sensors (SS1 and SS2) were explored for the colorimetric and fluorometric detection of Fe2+, Fe3+, and Cu2+ ions in the semi-aqueous medium. The "turn-off" fluorescence response of both sensors to these ions was due to the restriction in internal charge transfer. Job's plot and semi-empirical calculations revealed that SS1 and SS2 complexed with Cu2+ ions in a 1:1 ratio and Fe2+/3+ ions in a 2:1 ratio, respectively. The sensors were found to have high binding constant (K a) values and low detection limit values. FMO analysis using the semi-empirical quantum mechanics method revealed the decrease in energy gap after complexation with metal ions. Sensor-coated filter paper strips were prepared and analyzed, where the color changes in the strips could be utilized for the real-time detection of Fe2+, Fe3+, and Cu2+ ions.
RESUMEN
The present protocol describes an efficient, metal-free regioselective synthesis of 2-aroyl-3-arylimidazo[1,2-a]pyridines from 1,3-diaryl-prop-2-en-1-ones and 2-aminopyridine. The iodine-NH4OAc promoted reaction offers a novel route in the synthesis of 2-aroyl-3-arylimidazo[1,2-a]pyridines. This protocol offers significant flexibility in accessing medicinally important 2-aroyl-3-arylimidazo[1,2-a]pyridines with various substitution patterns.
RESUMEN
A wide range of 4,6-diarylated/heterylated pyridin-2(1H)-one derivatives were synthesized in good to excellent yields from 1,3-diarylated/heterylated-2-propen-1-ones (chalcones) in one pot under metal and base-free conditions. This domino reaction suggests a novel mechanism comprising of Michael addition followed by amination, subsequent intramolecular amidation and finally dehydronitrosation. The usefulness of the designed 4,6-diarylated/heterylated pyridin-2(1H)-one derivatives has further been demonstrated by synthesizing medicinally important 2,4,6-triaryl/heteryl pyridines via Pd-catalyzed cross-coupling reaction.
