Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Plantones , Semillas , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Semillas/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas Represoras/metabolismo , Proteínas Represoras/genéticaRESUMEN
A Pd-catalyzed reductive addition of organohalides, including aryl, alkenyl, and benzyl halides, to ynol ethers has been realized in the presence of 2-propanol, giving α,ß- and ß,ß-disubstituted olefinic ethers in satisfactory yields with excellent regio- and stereoselectivity. It represents the first highly regio- and stereoselective hydroarylation, hydroalkenylation, and hydrobenzylation of ynol ethers.
RESUMEN
An operationally simple and practical protocol for the synthesis of (E)-α-halo vinyl sulfides has been achieved via a highly regio- and stereoselective hydrohalogenation of alkynyl thioethers using lithium halides in HOAc or propionic acid at room temperature. It permits the formation of (E)-α-chloro and (E)-α-bromo vinyl sulfides in satisfactory yields with good to excellent stereoselectivities. Moreover, this work results in a new method for the assembly of stereodefined (E)- or (Z)-trisubstituted alkenes featuring the first coupling of the C-X bond of (E)-α-halo vinyl sulfides followed by a subsequent Ni-catalyzed coupling of the C-S bond with Grignard reagents.
Asunto(s)
Alquenos/síntesis química , Alquinos/química , Hidrocarburos Halogenados/síntesis química , Compuestos de Sulfhidrilo/química , Sulfuros/síntesis química , Alquenos/química , Hidrocarburos Halogenados/química , Estructura Molecular , Estereoisomerismo , Sulfuros/químicaRESUMEN
A highly regio- and stereoselective method for the synthesis of cis-1,2-dihaloalkenes through Pd-catalyzed coupling of haloalkynes and α,ß-unsaturated carbonyls has been reported. Excellent stereoselectivities (Z/E up to >98:2) were observed in most cases. This method was subsequently applied to synthesize the functionalized conjugated enyne via the mono-Sonogashira coupling reaction of cis-1-chloro-2-iodoalkene.
Asunto(s)
Aldehídos/química , Alquenos/química , Alquenos/síntesis química , Alquinos/química , Halógenos/química , Cetonas/química , Paladio/química , Catálisis , Estereoisomerismo , Especificidad por SustratoRESUMEN
An unprecedented Pd-catalyzed hydrohalogenation of alkynyl halides for the regio- and stereoselective synthesis of (Z)-1,2-dihaloalkenes has been realized using [(allyl)PdCl](2) as the catalyst and cis,cis-1,5-cyclooctadiene as the ligand. The advantages of this protocol are well illustrated by the assembly of trisubstituted (Z)-enynes and multifunctional benzenes via iterative cross-coupling reactions or tandem Diels-Alder-aromatization reactions, respectively.