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

The asymmetric heterogeneous catalytic reduction of carbonyl bonds by hydro gen transfer reduction or hydrogenation by means of molecular hydrogen as w ell 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 pende nt ligand or a chiral main chain polymer with ureas, thioureas and a diphos phine as functional groups. Comparison of the results obtained in these het erogeneous asymmetric reactions was made with those obtained in the homogen eous ones. (C) 2000 Elsevier Science S.A. All rights reserved.