Threonine‐Derived Phosphinite‐Oxazoline Ligands for the Ir‐Catalyzed Enantioselective Hydrogenation |
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Authors: | Frederik Menges Andreas Pfaltz |
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Abstract: | A series of chiral phosphinite‐oxazolines was synthesized in four steps starting from carboxylic acids and threonine methyl ester. In the asymmetric hydrogenation of a number of alkenes, iridium complexes of these ligands induced significantly higher enantioselectivities than the corresponding serine‐derived complexes. Enantiomeric excesses of 89 to 99% were obtained for unfunctionalized alkenes with turnover numbers of up to 5000. |
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Keywords: | asymmetric catalysis hydrogenation iridium ligand design N P‐ligands |
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