Ruthenium-bisphosphine-diamine catalysts

Asymmetric Hydrogenation of Prochiral Ketones by Ruthenium-Bisphosphine-Diamine Catalysts... 

Great care must be taken not to generalize these effects, as the addition of primary diamines to ruthenium bisphosphine complexes generates a very active catalyst for ketone hydrogenation after the addition of base (see Chapter 32). 

Three classes of catalysts have been studied for the asymmetric hydrogenation of imines. One class of catalyst is generated from late transition metal precursors and bisphosphines. These catalysts have typically been generated from rhodium and iridium precursors. A second class of catalyst is based on the chiral titanocene and zirconocene systems presented in the previous section on the asymmetric hydrogenation of unfunctionalized olefins. The third class of catalyst is used for the transfer hydrogenation of imines and consists of ruthenium or rhodium complexes containing diamine, amino tosylamide, or amino alcohol ligands. " ... 

The next quantum leap in catalysis after DuPhos has been the development of the ruthe-nium-diamine-bisphosphine catalysts (JST). This combination of ligands on ruthenium produces a highly active and enantioselective catalyst for the reduction of aryl ketones at mild conditions. Although this technology is relatively young, the potential is strong for many industrial processes that use this catalyst system. 

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