Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/37723
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Stereoselective Synthesis of Rhodium(I) 4-(Dialkylamino)triazol-5-ylidene Complexes |
Autor: | Ros, Abel CSIC ORCID CVN ; Alcarazo, Manuel; Iglesias-Sigüenza, Javier; Díez, Elena; Álvarez, Eleuterio CSIC ORCID ; Fernández, Rosario; Lassaletta, José M. CSIC ORCID | Palabras clave: | Stereoselective Rh(I) Triazolium Rhodium Dialkylamino Asymmetric hydrosilylation Temperatures N-heterocyclic |
Fecha de publicación: | 27-ago-2008 | Editor: | American Chemical Society | Citación: | Organometallics 27(18): 4555-4564 (2008) | Resumen: | The synthesis of 1-alkyl-1,2,4-triazolium salts containing chiral 4-dialkylamino substituents was accomplished by selective alkylation at N-1 of the corresponding 4-(dialkylamino)-1,2,4-triazoles. The latter were synthesized by reaction of N,N-dimethylformamidazine dihydrochloride with N,N-dialkylhydrazines in pyridine. Alternatively, the synthesis of 4-[(2S,5S)-2,5-diphenylpyrrolidin-1-yl]-1-phenyl-1,2,4-triazolium perchlorate was performed by reaction of 3-phenyl-1,3,4-oxadiazolium perchlorate with (2S,5S)-1-amino-2,5-diphenylpyrrolidine. These triazolium salts were transformed into neutral [RhCl(NHC)(COD)] complexes (NHC = 4-(dialkylamino)-1-alkyl(phenyl)triazol-5-ylidene) by reaction with [RhCl(COD)]2 in the presence of triethylamine. The products, featuring restricted C(carbene)−Rh bond rotation, were formed with high levels of selectivity in all cases, the de’s being >98% for complexes bearing the (2S,5S)-2,5-diphenylpyrrolidino group. A cationic heterobidentate NHC/S complex was also synthesized in a highly stereoselective way by alkylation of 4-[(2S,5S)-2,5-diphenylpyrrolidin-1-yl]-1,2,4-triazole with (R)-1-bromo-2-(cyclohexylthio)-3-methylbutane, followed by treatment of the resulting triazolium salt with [RhCl(COD)]2/Et3N and ensuing bromide abstraction by AgSbF6. A preliminary evaluation of the neutral and cationic Rh complexes in the asymmetric hydrosilylation of acetophenone indicated good catalytic activity and moderate enantioselectivities for most complexes, reaching a promising 62% ee in the case of the cationic complex. | Descripción: | 10 páginas, 6 figuras, 1 tabla, 8 esquemas. | Versión del editor: | http://dx.doi.org/10.1021/om800533g | URI: | http://hdl.handle.net/10261/37723 | DOI: | 10.1021/om800533g | ISSN: | 0276-7333 |
Aparece en las colecciones: | (IIQ) Artículos |
Mostrar el registro completo
CORE Recommender
SCOPUSTM
Citations
44
checked on 29-feb-2024
WEB OF SCIENCETM
Citations
42
checked on 16-feb-2024
Page view(s)
338
checked on 18-mar-2024
Google ScholarTM
Check
Altmetric
Altmetric
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.