Diastereoselectivity of Enolate Anion Protonation. H/D Exchange of β-Substituted Ethyl Butanoates in Ethanol-<i>d</i>
作者:Jerry R. Mohrig、Robert E. Rosenberg、John W. Apostol、Mark Bastienaansen、Jordan W. Evans、Sonya J. Franklin、C. Daniel Frisbie、Sabrina S. Fu、Michelle L. Hamm、Christopher B. Hirose、David A. Hunstad、Thomas L. James、Randall W. King、Christopher J. Larson、Hallie A. Latham、David A. Owen、Karin A. Stein、Ronald Warnet
DOI:10.1021/ja962631s
日期:1997.1.1
The stereochemistry of base-catalyzed H/D exchange on 13 β-substituted ethyl butanoates in ethanol-d has been studied in order to analyze the steric and electronic factors which control the diastereoselectivity of electrophilic attack on enolate anions. Electrophilic deuteration of the enolate anion also determines the stereoselectivity of 1,4-conjugate addition of ethanol-d to α,β-unsaturated esters
Enantioselective Synthesis of β-Aryloxycarboxylic Esters via Asymmetric Hydrogenation of β-Aryloxy-α,β-Unsaturated Esters
作者:Gavin W. Stewart、Michael Shevlin、Adam D. Gammack Yamagata、Andrew W. Gibson、Stephen P. Keen、Jeremy P. Scott
DOI:10.1021/ol302518y
日期:2012.11.2
A novel synthesis of beta-aryloxycarboxylic esters via asymmetric hydrogenation of the corresponding beta-aryloxy-alpha,beta-unsaturated esters has been demonstrated. Bis(norbornadiene)rhodium(I) tetrafluoroborate (1 mol %) and Walphos W008-1 were used to generate the saturated products with high enantioselectivity and in high yield. The tolerability of the reaction to a diverse range of substituents on the aromatic ring was also explored.