RESUMEN
A new protocol for the direct synthesis of 2-aminothiazole has been developed from oxime acetate and readily available sodium thiocyanate using a copper catalyst. The present transformation has good functional group tolerance. Various thiazoles were smoothly synthesized in good to excellent yields. The applicability of the present method has been extended to the formal synthesis of the non-steroidal and anti-inflammatory drug, fentiazac via the Sandmeyer reaction and Suzuki coupling.
RESUMEN
A direct oxidation of the bromo-derived Fischer-Borsche oxo-ring leading to carbazolequinone has been developed by using molecular iodine. This unprecedented transformation has been used for the modular synthesis of the anti-cardiotonic agent murrayaquinone. Furthermore, the present method has been generalized to a broad range of functional groups, with good to excellent yield.
Asunto(s)
Yodo , Estructura Molecular , Oxidación-ReducciónRESUMEN
A novel, efficient, and regioselective transition-metal-free one-pot synthesis of aryl sulfones via the reactive quinone imine ketal intermediate is demonstrated using easily accessible bench-stable sulfinate salts. A broad range of functionality on p-anisidine substrates as well as sulfinate salts was tolerated under mild reaction conditions to provide the corresponding aryl sulfones in good to excellent yields.
RESUMEN
The Beckmann rearrangement of ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and (18)O-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C-H activation were used as key steps in the formal total synthesis of antimalarial natural product isocryptolepine.
Asunto(s)
Antimaláricos/síntesis química , Alcaloides Indólicos/síntesis química , Quinolinas/síntesis química , Sulfato de Amonio/química , Catálisis , Dimetilsulfóxido/química , Depuradores de Radicales Libres/química , Radicales Libres/química , EstereoisomerismoRESUMEN
An efficient regioselective iodination of the Fischer-Borsche ring has been achieved using molecular iodine, in a one-pot synthesis. The acid-, metal-, and oxidant-free conditions of the present method are highly convenient and practical. Furthermore, the one-pot direct iodination process is extended to the concise synthesis of glycozoline, 3-formyl-6-methoxy-carbazole, and 6-methoxy-carbazole-3-methylcarboxylate natural alkaloids. This method has been proven to be tolerant to a broad range of functional groups, with good to excellent yields.