Palladium and rhodium complexes with planar-chiral carborane ligands

Brunner, Henri and Apfelbacher, Andreas and Zabel, Manfred (2001) Palladium and rhodium complexes with planar-chiral carborane ligands. EUROPEAN JOURNAL OF INORGANIC CHEMISTRY (4). pp. 917-924. ISSN 1434-1948

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Abstract

Base degradation of the prochiral 1-diphenylphosphanyl-2phenyl-1,2-dicarba-closo-dodecaborane (1) affords the planar-chiral 7-diphenylphosphanyl-8-phenyl-7,8-dicarbanido-undecaborate anion (2). Resolution of the racemic anion carried out using a well-established procedure, gave the internally diastereomeric palladium complexes 3R-R and 3R-S, These complexes were separated by fractional crystallization. A single-crystal X-ray analysis of 3R-R established the exo-nido bonding of the carborane ligand via the phosphorus atom and the adjacent BH group, and the (R) configuration of the carborane Ligand. The enantiomerically pure anions of 2 were liberated from the diastereomerically pure palladium complexes 3R-R and 3R-S, respectively, by subsequent addition of HCl and NaCN. The exo-nido-rhodium-carborane complexes 4-8 were prepared by heating 2eR or 2eS with [Rh(COD)Cl](2) and/or a chiral chelating phosphane, such as DIOP and BINAP, under reflux. The chiral complexes were tested under enantioselective catalysis conditions such as hydrogenation of acetamidocinnamic acid, hydrogenation of ketopantolactone, and hydrosilylation of acetophenone.

Item Type: Article
Uncontrolled Keywords: ENANTIOSELECTIVE CATALYSIS; ASYMMETRIC CATALYSIS; TERTIARY PHOSPHINES; METAL-COMPLEXES; METALLACARBORANES; HYDROGENATION; RESOLUTIONS; REACTIVITY; CRYSTAL; SYSTEM; chirality; carboranes; palladium; rhodium; asymmetric catalysis
Subjects: 500 Science > 540 Chemistry & allied sciences
Divisions: Chemistry and Pharmacy > Institut für Anorganische Chemie > Alumni or Retired Professors > Prof. Dr. Henri Brunner
Depositing User: Dr. Gernot Deinzer
Date Deposited: 07 Feb 2022 08:18
Last Modified: 07 Feb 2022 08:18
URI: https://pred.uni-regensburg.de/id/eprint/41533

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