(Eta3-phenylallyl)(phosphanyloxazoline)palladium complexes: X-ray crystallographic studies, NMR investigations, and Ab initio/DFT calculations

Chemistry. 2002 Jul 15;8(14):3103-14. doi: 10.1002/1521-3765(20020715)8:14<3103::AID-CHEM3103>3.0.CO;2-C.

Abstract

All possible (eta(3)-allyl)palladium complexes (1-4) of the ligand (4S)-[2-(2'-diphenylphosphanyl)phenyl]-4,5-dihydro-4-(2-propyl)-oxazole (L 1) and eta(3)-allyl ligands with one to three phenyl substituents at the terminal allylic centers were synthesized and characterized by X-ray crystal structure analysis and, with respect to allylic isomers, by NMR investigations. Equilibrium geometries, electronic structures, and relative energies of isomeric complexes were computed by restricted Hartree-Fock (RHF) and density functional theory (DFT) calculations; experimentally determined isomer ratios could be reproduced. The results allowed important conclusions to be drawn regarding the mechanism of Pd-catalyzed asymmetric allylic substitutions.