Dynamic kinetic resolution: asymmetric transfer hydrogenation of alpha-alkyl-substituted beta-ketoamides.
Dynamic kinetic resolution (deracemization) of various alpha-alkyl-substituted beta-ketoamides 1 via asymmetric transfer hydrogenation proceeded efficiently to give the corresponding syn-beta-hydroxy amides 3 in high diastereo- and enantioselectivities. Specifically, subjection of 1 to HCO(2)H and Et(3)N in the presence of 0.5-1 mol % of pentafluorobenzenesulfonyl-DPEN-Ru catalyst 2b at 30-40 degrees C in either PhCH(3) or CH(2)Cl(2) generated the syn-hydroxy product 3 selectively in 15-33:1 dr, 93-97% ee, and 75-88% isolated yields.
Limanto
John
J
Merck & Company, Inc., Merck Research Laboratories, Department of Process Research, P.O. Box 2000, Rahway, New Jersey 07065, USA. john_limanto@merck.com
Krska
Shane W
SW
Dorner
Benjamin T
BT
Vazquez
Enrique
E
Yoshikawa
Naoki
N
Tan
Lushi
L
D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006865:Hydrogenation; D007700:Kinetics; D015394:Molecular Structure; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis* / Q000737:chemistry
D000577:Amides; D047090:beta-Lactams; C520957:beta-ketoamide