New chiral phosphinooxathiane ligands for palladium-catalyzed asymmetric allylic substitution reactions

New chiral ligands, phosphinooxathianes 3 and 6, were synthesized easily and their ability as ligands were examined in Pd-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate to give an allylation product. Enantiomeric excess of up to 94% has been obtained using 1 mol% of [PdCl(η3-C3H5)]2 and 2 mol% of 3.