Synthesis of Electron-Rich CNN-Pincer Complexes, with N-Heterocyclic Carbene and (<i>S</i>)-Proline Moieties and Application to Asymmetric Hydrogenation
the silver carbene transfer route from the respective silver complex. The reaction with [RhCl(cod)]2 (cod = cycloocta-1,5-diene), PdCl2(CH3CN)2, or K[AuCl4] affords the corresponding cationic [Rh(cod)(ligand)]Cl, [PdCl(ligand)]Cl, and [AuCl(ligand)]Cl2 complexes in which the ligand functions effectively in a CNN coordination mode. The complexes catalyze the enantioselective hydrogenation of prochiral
New chiral ligands bearing two N-heterocyclic carbene moieties at a dioxolane backbone. Gold, palladium and rhodium complexes as enantioselective catalysts
Biscarbene ligands with two imidazolin-2-ylidene moieties at a chiral dioxolane backbone were used as ligands for gold, rhodium and palladium complexes. All new complexes showed varying degrees of enantioselectivity toward hydrogenation of prochiral alkenes with ees up to 95%.
Enantioselective hydrogenation of olefins by chiral iridium phosphorothioite complex covalently anchored on mesoporous silica
作者:S SAHOO、P KUMAR、F LEFEBVRE、S HALLIGUDI
DOI:10.1016/j.jcat.2007.12.002
日期:2008.2.15
performances in the heterogeneous asymmetrichydrogenation of itaconic acid and its derivatives. It was found that the catalytic activities and enantioselectivities of the heterogenized iridiumcomplex (IrPSSBA-15) in the hydrogenation reactions were comparable to its homogeneous analogue. Binol-derivedmonodentate phosphorothioite ligand in heterogeneously anchored form (iridiumcomplex) is a more effective catalyst
Optically active α-alkylsuccinates from the stereoselective alkylation of chiral imide enolates.
作者:Antoine Fadel、Jacques Salaün
DOI:10.1016/s0040-4039(00)82319-9
日期:1988.1
The chiral oxazolidinones and were alkylated by methyl bromoacetate, then subsequent removal of the chiral auxiliary provided readily with high stereoselectivity the α-alkylated succinates and . Acyloin condensation and bromination gave the optically active α-t-butylcyclobutanedione .
Development of homogeneous and heterogenized rhodium(i) and palladium(ii) complexes with ligands based on a chiral proton sponge building block and their application as catalysts
chiral ligands for obtaining complexes of rhodium(I) and palladium(II) by reaction with [RhCl(cod)]2, PdCl2(cod) or Pd(OAc)2. The complexes bearing triethoxysilane groups were immobilized on mesoporous MCM-41 in order to obtain new heterogeneous catalysts. Both materials are active in the hydrogenation of alkenes and could be recycled without loss of activity or enantioselectivity.