Carbon supported anchored homogeneous catalysts

In almost all of the previous descriptions of our Anchored Homogeneous Catalysts an alumina was the support used. However, the technique of using a heteropoly acid as the anchoring agent does not limit itself to only alumina as the solid support for these species. Some brief mention has been made of the use of carbon, clay, silica and lanthana as supports but nothing extensive was done with these materials. We report here some examples of the use of carbon supported anchored homogeneous catalysts for the hydrogenation of prochiral substrates at moderate to high substrate/catalyst ratios along with a comparison of these results with those obtained using the corresponding homogeneous catalysts under the same conditions. Particular attention will be paid to the use of the anchored chiral Rh(DuPhos) and Rh(BoPhoz) species in the hydrogenation of dimethyl itaconate. Reaction rates, product enantioselectivities and the extent of metal loss will be presented where appropriate.