The chiral phosphino-oxazoline ligand (S,R)-2-[4-(isopropyl)oxazol-2-yl]-2‘-bis(3,5-dimethylphenylphosphino)-1,1‘-binaphthyl, 6b, its Pd-dichloro complex, 9, the p-cyanoaryl complex
[PdBr(p-NC−C6H4](6b)], 10, a model for the Heck reaction, the cationic 1,3-diphenylallyl
derivative [Pd(η3-PhCHCHCHPh)(6b)]OTf, 11, a model for the allylic allylation, and the
Rh- and Ir-1,5-COD compounds [M(1,5-COD)(6b)]BF4, 12 and 13, respectively, have been
prepared. In enantioselective catalytic experiments, the presence of the 3,5-dimethylphenyl
groups generally increases the observed ee. The solid-state structure of PdCl2(6b), 9, has
been determined. 2-D and variable-temperature NMR experiments suggest that one of the
two 3,5-dimethyl P-aryl rings interacts selectively with the remaining ligands. Consequently,
the entire chiral pocket becomes slightly more rigid and the correlation with substrate
improves.