Application of chiral bis(phosphine) monosulfide ligands to palladium-catalyzed asymmetric allylic alkylation

The chiral bis(phosphine) monosulfide ligand (S)-BINAP(S) and its corresponding [(eta3-allyl)Pd(S-BINAP(S))]SbF 6 complex were synthesized and the Pd complex was used in the kinetic resolution of allylic acetates and benzoates in the course of the Pd-catalyzed asymmetric allylic alkylation reaction with sodium dimethylmalonate as the nucleophile. Very high S values (8.5-26) were observed for the kinetic resolution process; additionally, an unusual regioselectivity was noted when using unsymmetrically substituted allylic substrates, favoring the branched regioisomeric product.; The above catalytic system was also applied to the asymmetric synthesis of acyclic allylic esters by using a bulky carboxylate nucleophile, which proceeded in high ee (up to 90%). Additionally, a highly selective kinetic resolution was observed when using a 1,3-dimethylallyl substrate ( S = 38). Branched regioisomeric products were obtained with very high regioselectivity (>90%), which is highly unusual.; Asymmetric allylic amination was also attempted with the aforementioned catalytic system. Excellent enantioselectivities (many > 88%) were observed; the trend of producing the chiral, branched regioisomeric product continued in this study. Modification of the parent (S)-BINAP(S) ligand was found to increase the enantioselectivity of the reaction. X-ray crystallographic data confirmed the binding mode of the (S)-BINAP(S) ligand to be kappa2-P,S in the solid state.; A detailed look into the factors contributing to the observed unusual regioselectivity was undertaken in the context of Pd-catalyzed allylic amination. Numerous unsymmetrically substituted allylic substrates were screened. Solid-state and solution analyses of several unsymmetrically substituted [(eta 3-allyl)Pd((S)-BINAP(S)]SbF6 compounds were performed. Spin-saturation transfer 1H NMR experiments were performed in order to elucidate the dynamic behavior of two [(eta 3-allyl)Pd(kappa2-P,S)]SbF 6 compounds in solution. The hemilability of the P,S ligands was revealed.; A successful resolution of the axially chiral BIPHEP ligand on Rh was achieved with the aid of a chiral diene auxiliary ligand. Polarimetry measurements allowed for the determination of DeltaG‡ for the BIPHEP ligand on Rh.