RESUMO
Preliminary results concerning the first asymmetric synthesis of highly functionalized 1-benzamido-1,4-dihydropyridine derivatives via the reaction of hydrazones with alkylidenemalononitriles in the presence of ß-isocupreidine catalyst are reported. The moderate, but promising, enantioselectivity observed (40â»54% ee), opens the door to a new area of research for the asymmetric construction of new chiral 1,4-dihydropyridine derivatives, whose enantioselective catalytic preparation are still very limited. Moreover, the use of hydrazones for the enantioselective construction of chiral 1,4-dihydropyridines has been overlooked in the literature so far. Therefore, our research represents a pivotal example in this field which remains still unexplored.
Assuntos
Bloqueadores dos Canais de Cálcio/síntese química , Catálise , Di-Hidropiridinas/síntese química , Compostos Heterocíclicos/síntese química , Bloqueadores dos Canais de Cálcio/química , Di-Hidropiridinas/química , Di-Hidropiridinas/uso terapêutico , Compostos Heterocíclicos/química , Hidrazonas/química , Hidroxiquinolinas/química , Estrutura Molecular , Quinuclidinas/química , EstereoisomerismoRESUMO
Herein, we report our preliminary results concerning the first promising asymmetric synthesis of highly functionalized 2-oxospiro-[indole-3,4'-(1',4'-dihydropyridine)] via the reaction of an enamine with isatylidene malononitrile derivatives in the presence of a chiral base organocatalyst. The moderate, but promising, enantioselectivity observed (30%-58% ee (enantiomeric excess)) opens the door to a new area of research for the asymmetric construction of these appealing spirooxindole skeletons, whose enantioselective syntheses are still very limited.