512184-97-3Relevant articles and documents
Highly Selective Asymmetric Hydrogenation Using a Three Hindered Quadrant Bisphosphine Rhodium Catalyst
Hoge, Garrett,Wu, He-Ping,Kissel, William S.,Pflum, Derek A.,Greene, Derek J.,Bao, Jian
, p. 5966 - 5967 (2004)
A concise synthesis of both enantiomers of ligand 2 and rhodium complex 5 is presented. The crux of the synthesis is a chiral HPLC separation of the enantiomers of 4. Rhodium complex 5 possesses three hindered quadrants in the steric environment within which a substrate binds. Evidence is presented that this configuration leads to high enantioselectivity (>99% ee) for rhodium-catalyzed asymmetric hydrogenation of α-acetamido dehydroamino acids, 6a-e. High enantioselectivities are also reported for the hydrogenation of a substrate precursor, 8, of pharmaceutical candidate, pregabalin. Advantages for large-scale hydrogenation of 8 using catalyst 5a vs Rh-Me-DuPhos are discussed. Copyright
C1-symmetric bisphosphine ligands and their use in the asymmetric synthesis of pregabalin
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Page/Page column 15-16, (2008/06/13)
Materials and methods for preparing (S)-(+)-3-(aminomethyl)-5-methyl-hexanoic acid and structurally related compounds via enantioselective hydrogenation of prochiral olefins are disclosed. The methods employ novel chiral catalysts, which include C1-symmetric bisphosphine ligands bound to transition metals.
