Ligand tuning in asymmetric catalysis: Mono- and bis-phospholanes for a prototypical Pd-catalyzed asymmetric allylation reaction

Enantioselectivities and yields comparable to the best catalysts reported p reviously can be achieved in the addition of potassium dimethyl malonate to diphenylallyl acetate by the use of Pd(0) complexes of bis-phospholanes pr epared from D-mannitol. By appropriate changes in the C-2-C-5 substituents, rare example of a useful monophosphine can also be prepared by a similar r oute. In both instances chirality of C-3 and C-5 oxygen seems to play a cru cial role in the asymmetric induction.