N-Heterocyclic Carbene Complexes of Nickel as Efficient Catalysts for Hydrosilylation of Carbonyl Derivatives
作者:Lorena Postigo、Beatriz Royo
DOI:10.1002/adsc.201200389
日期:2012.10.8
Well-defined nickel(II) complexes bearing bidentate tetramethylcyclopentadienyl-functionalised N-heterocycliccarbene ligands (Cp*-NHCMe)NiX (X=Cl, O-t-Bu) have been prepared and applied as efficientcatalysts for the hydrosilylation of carbonyl groups. The nickel-alkoxide (Cp*-NHCMe)Ni(O-t-Bu) complex displayed remarkable catalytic activity in the reduction of aldehydes, affording quantitative conversion
Unprecedented synthesis of iron–NHC complexes by C–H activation of imidazolium salts. Mild catalysts for reduction of sulfoxides
作者:João M. S. Cardoso、Beatriz Royo
DOI:10.1039/c2cc31564e
日期:——
A direct synthesis of bidentate cyclopentadienyl-functionalised NHC-iron(II) complexes by using imidazolium salts and commercially available Fe(3)(CO)(12) is developed. These well-defined iron-NHCcomplexes efficiently catalyse the reduction of sulfoxides under mild conditions. Radical scavenging experiments indicate the presence of free radicals in the catalytic reaction.
First Cp*-Functionalized N-Heterocyclic Carbene and Its Coordination to Iridium. Study of the Catalytic Properties
作者:André Pontes da Costa、Mónica Viciano、Mercedes Sanaú、Sonia Merino、Juan Tejeda、Eduardo Peris、Beatriz Royo
DOI:10.1021/om701186u
日期:2008.3.24
alized N-heterocycliccarbene ligand (Cp*-NHCMe) has been prepared and coordinated to iridium upon reaction with [Ir(μ-Cl)(cod)]2. The chiral Ir complex is obtained as a racemic mixture of the two possible enantiomers, and its crystal structure is described. The new compound shows high catalytic activity toward transfer hydrogenation, β-alkylation of secondaryalcohols with primaryalcohols, and amination
Preparation of Cp-Functionalized N-Heterocyclic Carbene Complexes of Ruthenium. Resolution of Chiral Complexes and Catalytic Studies
作者:André Pontes da Costa、José A. Mata、Beatriz Royo、Eduardo Peris
DOI:10.1021/om100090c
日期:2010.4.12
A series of piano-stool ruthenium(II) complexes bearing bidentate cyclopentadienyl-functionalized N-heterocyclic carbene ligands Ru(Cp-X-NHC)(CO)I [Cp = tetramethylcyclopentadienyl (Cp*) and tetrabenzylcyclopentadienyl (Cp-Bz)] have been prepared by the diastereoselective reaction of the imidazolium Cp-X-NHC proligands with [Ru-3(CO)(12)]. The new complexes have been characterized by spectroscopic techniques and X-ray diffraction methods. The enantiopure complexes have been separated by preparative thin-layer chromatography of the diastereomeric mixtures resulting from the reaction of the Ru(Cp-X-NHC)(CO)I compounds with an auxiliary chiral amine. Ru(Cp*-NHC)(CO)I is an efficient catalyst for the isomerization of allylic alcohols both in water and in THF.