RESUMEN
An efficient cascade ß-metalation/addition/cyclization reaction promoted by LDA is described in which 3-amino furans were constructed from enaminones and aldehydes. A broad range of substituents on the starting compounds was tolerated, and the polysubstituted furans were gained with moderate to excellent yields within 2 h.
RESUMEN
A highly efficient BF3·Et2O-catalyzed cascade reaction of enaminones with propargylic alcohols under mild reaction conditions has been developed. This methodology offers regioselective access to multisubstituted 1,2-dihydropyridines in good to excellent yields.
Asunto(s)
Alquinos/química , Aminas/química , Dihidropiridinas/síntesis química , Ácidos de Lewis/química , Propanoles/química , Catálisis , Ciclización , Dihidropiridinas/química , Estructura Molecular , EstereoisomerismoRESUMEN
A highly efficient palladium-catalyzed cascade reactions of aryloxy-enynes with aryl halides under mild reaction conditions has been developed. This methodology offers rapid access to 2,3,4-trisubstituted furans in good to excellent yields in a regioselective manner.
Asunto(s)
Alquinos/química , Éteres/química , Furanos/síntesis química , Hidrocarburos Halogenados/química , Compuestos Organometálicos/química , Paladio/química , Catálisis , Ciclización , Furanos/química , Estructura Molecular , EstereoisomerismoRESUMEN
A series of (E)-1-aryloxy-1-en-3-ynes has been prepared by Sonogashira coupling of 2-bromo-3-aryloxypropenoates with terminal alkynes using Pd(PPh(3))(4) and CuI as the catalysts in Et(3)N. The resulting enynyl-aryl ethers are found to be highly applicable to the synthesis of 2,4-disubstituted furans with an ester group at C-4 position through an Au/Ag-catalyzed annulation reaction under extremely mild reaction conditions.
Asunto(s)
Alquinos/química , Furanos/síntesis química , Oro/química , Catálisis , Cobre/química , Ciclización , Éteres/química , Paladio/química , Plata/químicaRESUMEN
3-Acylindoles undergo nucleophilic-type reactions with Grignard reagents to efficiently afford either cis- or trans-substituted indolines, depending on the different quenching procedures. The enolate intermediate could be trapped by aryl acyl chlorides to provide indolines bearing a quaternary carbon center with high stereoselectivity. In contrast, the use of benzyl bromide as an electrophile results in the fragmentation of the indole ring. The indoline products could be easily transformed into indoles through oxidation with DDQ in a one-pot manner.