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
Synthesis of hindered functionalized ethers via high-pressure addition of alcohols to acrylic compounds
作者:Gérard Jenner
DOI:10.1016/s0040-4039(01)00872-3
日期:2001.7
or β-Substituted acrylic compounds react sluggishly or not at all. In this case, high-pressure activation can remove steric inhibition leading to good yields of the corresponding ethers. Reactions involving crotonic compounds (hindered β reaction center) show higher pressure dependence than the corresponding additions of alcohols to methacrylic analogs (free β reaction center). This is in agreement
Effect of pressure on sterically congested cyanoalkylation reactions of alcohols
作者:G. Jenner
DOI:10.1016/s0040-4020(02)00347-2
日期:2002.5
The pressure effect on the phosphine-catalyzed nucleophilic addition of alcohols to unsaturated nitriles is examined. As a general result, pressure promotes these reactions. Their sensitivity to pressure increases with increasing steric congestion of either the alcohol or the nitrile. Activation volumes are found to be very negative pointing not only to a late transition state, but essentially to a
Addition of Alcohols to Acrylic Compounds Catalyzed by Mg–Al LDH
作者:F. Teodorescu、M. Deaconu、E. Bartha、R. Zăvoianu、O. D. Pavel
DOI:10.1007/s10562-013-1108-1
日期:2014.1
adsorption of organic acids with different pKa values and N2 adsorption–desorption isotherms. The catalytic activity of these solids was evaluated in 1,4-addition of saturated linear alcohols to different acrylic compounds. All these reactions arose with high selectivity in the desired product. No by-products were detected by means of GC–MS chromatography and 1H NMR.Graphical Abstract
Template catalysis by manganese pincer complexes: oxa- and aza-Michael additions to unsaturated nitriles
作者:Shan Tang、David Milstein
DOI:10.1039/c9sc03269j
日期:——
alcohols and amines. Mechanistically, the catalysis is mostly ligand based. Reaction of the dearomatized PNN–Mn complex with 2-pentenenitrile or 3-pentenenitrile furnished an enamido–Mn complex. The equilibrium between an enamido complex and a ketimido complex, and reversible C–C bond formation with the ligand are proposed to play central roles in the catalysis.