Structural Chemistry of Chiral BINAP .eta.3-Allyl Complexes of Pd(II). Multinuclear NMR and X-ray Diffraction Studies on Exo-Methylene Cyclopentene and .beta.-Pinene Allyl Complexes

X-ray structural results for the S-BINAP pinene allyl compound [Pd(eta(3)-C10H15)(S-BINAP)]CF3SO3 (1) and the R-BINAP, exo-methylene cyclopentene allyl complex [Pd(eta(3)-C6H9)(R-BINAP)]CF3SO3 (2) together with multidimensional H-1, C-13, and P-31 NMR results for these and the new chiral allyl complex [Pd(eta(3)-C6H9)(S,S-CHIRAPHOS)]CF3SO3 (3) are presented. The results are interpreted in terms of differences in the chiral pockets between BINAP and S,S-CHIRAPHOS, i.e. the former has a phenyl array with more pronounced axial and equatorial character. The equatorial phenyl groups are suggested to intrude more into the sphere of the allyl ligand than do the axial phenyl groups. The differences in populations between the diastereomers for 2, ca. 8:1, and for 3, ca. 6:4, are explained. Several new empirical NMR tools, based on NOEs, are suggested to, help in assigning the different coordinated faces of the eta(3)-C6H9 ligand. X-ray data for 1, ortho rhombic, space group P2(1)2(1)2(1), 11.762(1) Angstrom, b = 18.690(9) Angstrom, c = 21.240(3) Angstrom, V = 4669(2) Angstrom(3), for 2, monoclinic, space group P2(1), a = 10.786(3) Angstrom, b = 11.250(5) Angstrom, c = 20.154(5) Angstrom, beta = 101.72(2)degrees, V = 2395(1) Angstrom(3).