Phase Transfer Catalysis of Henry and Darzens Reactions

Layla Mhamdi,Younes Moussaoui,Hafedh Bohli,Ridha Ben Salem

doi:10.4236/ijoc.2011.13018

Abstract

We describe in this work the influence of the addition of phase transfer catalyst in heterogeneous medium liquid/liquid on the output of the reactions of Darzens and Henry. It proves that the reaction of Darzens is favoured in the presence of low base such as K2CO3 and Et3N. Phase transfer catalysis is an efficient activation method in Darzens and Henry reactions. Thus, the Ethylene Diammonium Diacetate (EDD) has a comparable catalytic activity has that of quaternary ammonium salts in the reaction of Darzens.

Highlights

The formation of a carbon-carbon bond is the fundamental reaction in organic synthesis [1,2,3,4,5]
Effect of the base: We have examined the nature of the base in the Henry reaction involving benzaldehyde and various nitroalkanes in aqueous solution (Table 1)
The results are in agreement with those of Zhou et al [39] who found that Henry reaction of aromatic and aliphatic aldehydes with nitromethane is promoted by triethylamine in water.(Figure 1.)

Summary

Introduction

The formation of a carbon-carbon bond is the fundamental reaction in organic synthesis [1,2,3,4,5] To this respect, Henry [6,7,8,9] and Darzens [10,11,12] reactions can be considered as excellent tools to give access to multifunctional compounds [13,14]. The Henry reaction [15] consists of the addition of a nitronate nucleophile on the double bond of a carbonyl compound. It proceeds usually at room temperature in the presence of a base to afford a β-nitroalcool. Ku et al [29] reported the asymmetric synthesis of trans-α,β-epoxysulfones by the catalytic phasetransfer Darzens reaction of chloromethyl phenyl sulfone with various aromatic aldehydes in the presence of the cinchona alkaloid-derived chiral phase-transfer catalysts

Methods

Results

Conclusion