<i>Z</i>-Selective Horner−Wadsworth−Emmons Reaction of α-Substituted Ethyl (Diarylphosphono)acetates with Aldehydes<sup>1</sup>
作者:Kaori Ando
DOI:10.1021/jo981337a
日期:1998.11.1
New Horner-Wadsworth-Emmons reagents, ethyl 2-(diarylphosphono)propionates (2), ethyl 2-(diarylphosphono)hexanoates (3), and ethyl 2-(diarylphosphono)-3-methylbutanoates (4) were prepared by alkylation of ethyl (diarylphosphono)acetates. The reaction of 2-4 with various types of aldehydes gave Z-alpha,beta-dialkyl-alpha,beta-unsaturated esters highly selectively. Remarkable temperature-dependent selectivity was observed in the reaction of (PhO)(2)P(O)CHBuCO2Et with octyl aldehyde.
<i>cis</i>-Specific Hydrofluorination of Alkenylarenes under Palladium Catalysis through an Ionic Pathway
作者:Enrico Emer、Lukas Pfeifer、John M. Brown、Véronique Gouverneur
DOI:10.1002/anie.201310056
日期:2014.4.14
paper describes the hydrofluorination of alkenes through sequential H− and F+ addition underpalladiumcatalysis. The reaction is cis specific, thus providing access to benzylic fluorides. The mechanism of this reaction involves an ionicpathway and is distinct from known hydrofluorinations involving radical intermediates. The first catalytic enantioselective hydrofluorination is also disclosed.