Highly E-selective solvent-free Horner–Wadsworth–Emmons reaction catalyzed by DBU

Abstract

The solvent-free Horner–Wadsworth–Emmons reaction of triethyl phosphonoacetate with a variety of aldehydes was catalyzed by DBU in the presence of K2CO3 to give E-α,β-unsaturated esters highly selectively (99: 1 for most of the reactions). The reaction with ketones gave trisubstituted olefins with good to high E-selectivity by DBU-Cs2CO3. © 2011 The Royal Society of Chemistry.