Ruthenium using homogeneous chiral

Table I. Hydrogenation of Unsaturated Organic Substrates Using Homogeneous Chiral Ruthenium and Rhodium Catalysts...

The first transition metal catalysis using BINAP-ruthenium complex in homogeneous phase for enantioselective hydrogenation of P-ketoesters was developed by Noyori and co-workers [31]. Genet and co-workers described a general synthesis of chiral diphosphine ruthenium(II) catalysts from commercially available (COD)Ru(2-methylallyl)2 [32]. These complexes preformed or prepared in situ have been found to be very efficient homogeneous catalysts for asymmetric hydrogenation of various substrates such as P-ketoesters at atmospheric pressure and at room temperature [33]. 

Jessop and co-workers have pointed out that homogeneous catalysis in supercritical fluids can offer high rates, improved selectivity, and elimination of mass-transfer problems.169 They have used a ruthenium phosphine catalyst to reduce supercritical carbon dioxide to formic acid using hydrogen.170 The reaction might be used to recycle waste carbon dioxide from combustion. It also avoids the use of poisonous carbon monoxide to make formic acid and its derivatives. There is no need for the usual solvent for such a reaction, because the excess carbon dioxide is the solvent. If the reaction is run in the presence of dimethy-lamine, dimethylformamide is obtained with 100% selectivity at 92-94% conversion.171 In this example, the ruthenium phosphine catalyst was supported on silica. Asymmetric catalytic hydrogenation of dehydroaminoacid derivatives (8.16) can be performed in carbon dioxide using ruthenium chiral phosphine catalysts.172... 

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