Marked deuterium isotope effects on the enantioselectivity in rhodium-catalyzed asymmetric hydrogenation of enamides.
Deuterium isotope effects on the enantioselectivity in the rhodium-catalyzed asymmetric hydrogenation of enamides and related substrates have been studied. Distinct deuterium isotope effects were observed in the hydrogenation of aryl-substituted enamides having an ortho substituent that is capable of forming a hydrogen bond. The observed isotope effects are interpreted in terms of the competitive reactions of two dihydride intermediates and dideuteride intermediates that exist in equilibrium in the catalytic cycle.
Imamoto
Tsuneo
T
Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. imamoto@faculty.chiba-u.jp
Itoh
Takuma
T
Yoshida
Kazuhiro
K
Gridnev
Ilya D
ID