Book of abstracts version 5

The kinetics of the Knoevenagel condensation with amino
acid-based catalytic intermediaries.
Author
Wolf Elenbaas
Academy of Technology for Health and Environment
Avans Hogeschool, Breda
Jack van Schijndel
Abstract
One of the most useful bonds to form in organic chemistry are carbon -carbon bonds, yet these bonds are very difficult to
form. Even though it is possible with alkyl halides and/or with heave metal-ligand complexes, these reactions are very
environment unfriendly [1]. The Knoevenagel or aldol condensation is an alternative way to form these bonds. Durin g
these reactions a carbon-carbon bond is formed between an aldehyde and a ketone. The difference between these
reactions are the catalysts that is used. The aldol condensation uses acids or bases to catalyse the reaction and during the
Knoevenagel condensation amines are used. Knoevenagel has discovered that using amines greatly increases this reaction
rate, even if a very small amount of amine is added [2].
In this project the catalytic intermediaries are synthesised with an amine with benzaldehyde, whic h forms a Schiff base or
aminal, depending on what order of amine is used. In Figure 1 are the structures shown of some of the catalytic
intermediaries. Once these intermediaries have been isolated and purified, they are used in the Knoevenagel
condensation. In Figure 2 is the Knoevenagel condensation shown with benzaldehyde and dibenzyl -malonate. The yield
was determined on the HPLC and the reaction rates were calculated.
Keywords: Organic catalysts, Reaction kinetics.
Table of content
Figure 1: Structures of the catalytic intermediaries after
benzaldehyde has reacted with different orders of amines.
Figure 2: Reaction equation of the
Knoevenagel condensation.
[1] Wade L. G., Simek J.W., Organic chemistry. (2016) Reactions of Organometallic compounds: 514 -530.
[2] Knoevenagel E., Ueber eine darstellungsweise der glutarsäure. Berichte der deutschen chemischen Gesellschaft.
1894;27(2):2345-2346.
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