RESUMO
Electrochemically induced catalytic multicomponent transformation of isatins, 3-methyl-2-pyrazolin-5-ones and malononitrile in ethanol in an undivided cell in the presence of sodium bromide as an electrolyte results in the formation of spirooxindoles with fused functionalized pyrano[2,3-c]pyrazole system in 78-99} yields. The developed efficient electrocatalytic approach to medicinally relevant spirocyclic [indole-3,4'-pyrano[2,3-c]pyrazoles] is beneficial from the viewpoint of diversity-oriented large-scale processes and represents a novel example of facile environmentally benign synthetic concept for electrocatalytic multicomponent reaction strategy.
Assuntos
Isatina/química , Nitrilas/química , Pirazolonas/química , Compostos de Espiro/síntese química , Brometos/química , Catálise , Ciclização , Eletroquímica , Etanol/química , Modelos Químicos , Estrutura Molecular , Compostos de Sódio/química , Compostos de Espiro/químicaRESUMO
In situ resolution of the rapidly racemising diphosphine BIPHEP and its relatives with the cationic Rh complex of (S,S)-bicyclonona-2,6-diene permits the asymmetric hydrogenation of dehydroamino esters.