Formation of Chiral<i>α</i>-Monofluorinated-<i>β</i>-amino Esters through Organocatalytic Asymmetric Reduction of<i>α</i>-Fluoro-<i>β</i>-enamino Esters by Trichlorosilane
作者:Peng Zhang、Chao Wang、Li Zhou、Jian Sun
DOI:10.1002/cjoc.201201067
日期:2012.11
A concise method was developed to prepare chiral α‐monofluorinated‐β‐amino estersthrough N‐sulfinyl urea catalyzed asymmetric hydrosilylation of α‐fluoro‐β‐enamino esters, which affords high yields, good to high diastereoselectivities (up to>99/1), and moderate to good enantioselectivities (up to 83% ee).
Enantioselective Aza-Henry Reaction with an <i>N</i>-Sulfinyl Urea Organocatalyst
作者:MaryAnn T. Robak、Monica Trincado、Jonathan A. Ellman
DOI:10.1021/ja075653v
日期:2007.12.1
simultaneously acidify the urea and provide asymmetric induction in hydrogen-bond-catalyzed reactions. The utility of this new catalyst structure is demonstrated by the high selectivity provided in the aza-Henryreaction not only for aromatic N-Boc imine substrates but also for aliphatic imines for which enantioselective H-bonding catalysis has not previously been demonstrated.