Ligand tuning in asymmetric catalysis: mono- and bis-phospholanes for a prototypical Pd-catalyzed asymmetric allylation reaction
[structures: see text] Enantioselectivities and yields comparable to the best catalysts reported previously can be achieved in the addition of potassium dimethyl malonate to diphenylallyl acetate by the use of Pd(0) complexes of bis-phospholanes prepared from D-mannitol. By appropriate changes in the C2-C5 substituents, rare example of a useful monophosphine can also be prepared by a similar route. In both instances chirality of C3 and C5 oxygen seems to play a crucial role in the asymmetric induction.
Yan
YY
Department of Chemistry, The Ohio State University, Columbus 43210, USA.
RajanBabu
TV