Tetrahedron letters

New efficient catalysts for enantioselective transfer hydrogenations

K Püntener, L Schwink, P Knochel

Index: Puentener, Kurt; Schwink, Lothar; Knochel, Paul Tetrahedron Letters, 1996 , vol. 37, # 45 p. 8165 - 8168

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Citation Number: 102

Abstract

New C2-symmetrical diaminoferrocenyl derivatives 3 and 2-amino (sulfonamido) cyclohexanes 4 were found to be highly active ligands for the ruthenium catalyzed asymmetric transfer hydrogenation of ketones. Contrary to many existing catalytic systems, the ligands 3 show a high activity at 25° C and operate even at− 30° C (up to 90% ee). On the other hand, the slightly less active ligands 4 are very easily prepared and are highly ...