Rh-DuPHOS-catalyzed enantioselective hydrogenation of enol esters. Application to the synthesis of highly enantioenriched α-hydroxy esters and 1, 2-diols
MJ Burk, CS Kalberg, A Pizzano
文献索引：Burk, Mark J.; Kalberg, Christopher S.; Pizzano, Antonio Journal of the American Chemical Society, 1998 , vol. 120, # 18 p. 4345 - 4353
The asymmetric hydrogenation of α-(acetyloxy)-and α-(benzoyloxy) acrylates 4 catalyzed by cationic rhodium-DuPHOS complexes has been examined. A wide range of substrates (4) were prepared via a convenient Horner-Emmons condensation protocol, and subsequently hydrogenated under mild conditions (60 psi of H2) at substrate-to-catalyst ratios (S/C) of 500. Overall, enol ester substrates 4 were reduced by the cationic Et-DuPHOS-Rh ...
