Dynamic Kinetic Resolution: Asymmetric Transfer Hydrogenation of α-Alkyl-Substituted β-Ketoamides
2009; American Chemical Society; Volume: 12; Issue: 3 Linguagem: Inglês
10.1021/ol902715d
ISSN1523-7060
AutoresJohn Limanto, Shane W. Krska, Benjamin Dorner, Enrique Vázquez, Naoki Yoshikawa, Lushi Tan,
Tópico(s)Asymmetric Synthesis and Catalysis
ResumoDynamic 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.
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