asymmetric α‐hydroxylation of β‐indanone esters and β‐indanone amides using peroxide as the oxidant was realized with a new C‐2′ substituted Cinchona alkaloid derivatives. The two enantiomers of α‐hydroxy‐β‐indanone esters could be obtained by simply changing the oxidant. This protocol allows a convenient access to the corresponding α‐hydroxy‐β‐indanone esters and α‐hydroxy‐β‐indanone amides with up to
Bifunctional Ammonium Salt Catalyzed Asymmetric α-Hydroxylation of β-Ketoesters by Simultaneous Resolution of Oxaziridines
作者:Johanna Novacek、Joseph A. Izzo、Mathew J. Vetticatt、Mario Waser
DOI:10.1002/chem.201604153
日期:2016.11.21
Chiral bifunctional urea‐containing ammonium salts were found to be very efficient catalysts for asymmetric α‐hydroxylation reactions of β‐ketoesters with oxaziridines under base‐free conditions. The reaction is accompanied by a simultaneous kinetic resolution of the oxaziridine and a plausible and so far unprecedented bifunctional transition‐state model has been obtained by means of DFT calculations
A strategy of visible light‐induced salan‐copper(II)‐catalyzed asymmetric α‐hydroxylation of β‐keto ester with utilization of sustainable air as the oxidant was developed. This protocol allows convenient access to a number of enantioenriched α‐hydroxyl β‐keto esters (up to 95% yield, 96% ee), especially for β‐keto methyl esters that are valuable architectures in pharmaceuticals, including the key intermediate