Asymmetric Synthesis of <i>anti</i>-α-Substituted β-Amino Ketones from Sulfinimines
作者:Franklin A. Davis、Peng Xu
DOI:10.1021/jo2002352
日期:2011.5.6
Previously unknown, enantiopure, beta-amino ketones were prepared in modest yield by addition of lithium reagents to N-sulfinyl anti-alpha-substituted beta-amino Weinreb amides. Grignard reagents failed to add to these Weinreb amides in contrast to the syn-alpha-substituted isomers which did. The anti-alpha-substituted beta-amino Weinreb amides were prepared by addition of LiN(OMe)Me to the corresponding N-sulfinyl anti-alpha-substituted beta-amino esters because alpha-alkylation of N-sulfinyl beta-amino Weinreb amide enolates resulted in poor diastereoselectivities.
Asymmetric Synthesis of <i>syn</i>-α-Substituted β-Amino Ketones by Using Sulfinimines and Prochiral Weinreb Amide Enolates
作者:Franklin A. Davis、Minsoo Song
DOI:10.1021/ol0708166
日期:2007.6.1
Syn-alpha-substituted beta-amino Weinrebamides are new chiral building blocks for asymmetricsynthesis of syn-alpha-substituted beta-amino acids, aldehydes, and ketones and are prepared by addition of prochiral lithium enolates of Weinrebamides to sulfinimines (N-sulfinyl imines).