Место издания:Prague, Czech Republic. Book of Abstracts Prague
Первая страница:166
Последняя страница:(P-047)
Аннотация: Detailed analysis of the parameters of the 1H NMR spectra and X-ray diffraction data was performed for a series of the adducts of chiral α-arylalkylaminate palladacycles with P-donors including dozens of previously prepared or known complexes with achiral or P*-chiral phosphine or phosphite auxilliary ligands.
It was shown that the configuration of the asymmetric α-arylalkylaminate carbon atom defines the stereochemistry of the twisted palladacycle and of the tetrahedrally distorted coordination environment of the metal. In structures with only α-C*-stereocentre chirality transfer was carried out according to the scheme:
from (SC)-С*-stereocentre to lambda(SC)-conformation and to LAMBDA(SC)-quasi-tetrahedron, or
from (RC)-С*-stereocentre to delta(RC)-conformation and to DELTA(RC)-quasi-tetrahedron.
The palladacycle conformation was estimated from the sign of the torsion angle C1-Pd-N-Cα (negative or positive for lambda or delta conformation, respectively). The stereochemistry of tetrahedral distortion was deduced from the sign of the torsion angle N...C1...P...Cl (positive or negative for LAMBDA or DELTA configuration, respectively). As the final point of the chain of chirality transfer events, we can mention that in all (SC)-configurated complexes phosphorus atom of the auxilliary ligand Q is located under the metallated aromatic ring (syn to the R substituent at the α-C*-stereocentre), according to the positive sign of the torsion angle P-Pd-C1-C6; and opposite is true for the complexes of (R)-configuration.