| 14628300 |
Magiera D, Szmigielska A, Pietrusiewicz KM, Duddeck H: Secondary phosphine oxides: tautomerism and chiral recognition monitored by multinuclear NMR spectroscopy of their Rh2 [(R)-MTPA] 4 adducts. Chirality. 2004 Jan;16(1):57-64.
Six secondary phosphine oxides and their tautomeric equilibria as free ligands and in the presence of an equimolar amount of the chiral dirhodium complex Rh* are described and discussed. Discrimination of enantiomers is easily possible by inspecting the (31) P NMR resonances; some (1) H and (13) C NMR resonances are useful as well. H/D exchange of the acidic protons in the phosphine oxides takes place with acetone-d (6), the solvent additive, after some hours but does not obscure the chiral recognition experiment. (103) Rh,(31) P coupling constants are discussed briefly. Decomposition of ligand molecules in 1:1-Rh*-adducts occurs slowly but completely. |
81(1,1,1,1) |