Recent progress in asymmetric heterogeneous catalysis: use of polymer-supported catalysts

The asymmetric heterogeneous catalytic reduction of carbonyl bonds by hydrogen transfer reduction or hydrogenation by means of molecular hydrogen as well as the asymmetric allylic substitution of allylic acetates are reported. In order to perform these reactions, new polymer-supported catalysts were employed. These polymers are either a Merrifield resin with a chiral pendent ligand or a chiral main chain polymer with ureas, thioureas and a diphosphine as functional groups. Comparison of the results obtained in these heterogeneous asymmetric reactions was made with those obtained in the homogeneous ones.