P-31, C-13, AND H-1-NMR STUDIES ON CHIRAL ALLYL FERROCENYLDIPHOSPHINE COMPLEXES OF PALLADIUM(II)

A series of complexes of the type [Pd(eta(3)-allyl)(JOSIPHOS)]CF3SO3, containing either the beta-pinene, eta(3)-C10H15, or the eta(3)-C3H5 ligands and the new chiral 1,2-ferrocenyldiphosphine ligands, JOSIPHOS, have been studied using multidimensional NMR spectroscopy (JOSIPHOS, 5, = (Cp)Fe{C5H3(1-CH(CH3)PR(2)(1))-2-PR(2)(2))}, (R(1) = Cy, R(2) = Ph, a; R(1) = Ph, R(2) = Cy, b; R(1) = Ph, R(2) = Ph, c). A structural comparison based on NOE data for the cation [Pd(eta(3)-C10H15)(5a)](+) with NOE data from the analogous cations of S-BINAP and S,S-CHIRAPHOS suggests that coordinated 5a intrudes more into the coordination sphere of the allyl Ligand than do either S-BINAP or S,S-CHIRAPHOS. The nature of the chiral environment for 5a in [Pd(eta(3)-C10H15)(5a)] CF3SO3, 4d, is described. 2-D exchange spectroscopy for four cationic complexes of the type [Pd(eta(3)-C3H5)(JOSIPHOS)](+), which contain different JOSIPHOS modifications, reveals a selective eta(3)-eta(1)-eta(3) isomerization, which, for the cations with 5a,b, involves opening of the Pd-C allyl bond cis to the PCy(2) and trans to the PPh(2) moiety. The eta(3)-eta(1)-eta(3) selectivity is shown to be steric and not electronic in origin.P-31, C-13 and H-1 NMR data are reported.