CHIRAL P,S-LIGANDS BASED ON BETA-D-THIOGLUCOSE TETRAACETATE - PALLADIUM(II) COMPLEXES AND ALLYLIC ALKYLATION

The new chelating P,S-ligands phenylphosphino)benzy)]thio)-beta-D-gluc opyranose, [(2-Ph(2)PC(6)H(4)CH(2))SCHCH(OAc)CH(OAc)CH(OAc) CH(CH2OAc) O, 2] and lohexylphosphino)benzyl)thio)-beta-D-glucopyranose (2)-PC6H4 CH2)SCHCH(OAc)CH(OAc)CH(OAc)CH(CH2OAc)O,, 3] as well as their (1,3-dip henylallyl)palladium(II) cationic complexes [Pd(eta(3)-PhCHCHCHPh)(2)] PF6, 6, and [Pd(eta(3)-PhCHCHCHPh)(3)]PF6, 7, and one eta(3)-C3H5 comp lex [Pd(eta(3)-C3H5)(2)]PF6, 5, have been prepared. The solid-state st ructure of [Pd(eta(3)-C3H5)(2)]PF6, 5, has been determined by X-ray di ffraction methods and found to have the S-sugar substituent and one of the P-phenyl rings in pseudo-axial positions on the same side of the P-Pd-S coordination plane. Detailed NMR measurements for 6 reveal the presence of two diastereomeric isomers whereas for 7 four diastereomer s are found. 2-D exchange NMR is used to characterize several of the s elective equilibria within 6 and 7. On the basis of the observed ee in the enantioselective homogeneous allylic alkylation of 7, it is sugge sted that the reaction kinetics for the four isomers are not all the s ame.