TY - JOUR
T1 - The combined role of catalysis and solvent effects on the biginelli reaction
T2 - improving efficiency and sustainability
AU - Clark, James H
AU - Macquarrie, Duncan J
AU - Sherwood, James
N1 - Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2013/4/15
Y1 - 2013/4/15
N2 - The traditional Biginelli reaction is a three-component condensation between urea, benzaldehyde and an acetoacetate ester to give a dihydropyrimidinone. An investigation into catalytic and solvent effects has returned the conclusion that the diketo-enol tautomerisation equilibrium of the dicarbonyl reactant dictates the yield of the reaction. Whereas the solvent is responsible for the tautomerisation equilibrium position, the catalyst only serves to eliminate kinetic control from the reaction. Generally, to preserve reaction efficiency and improve sustainability, bio-derivable p-cymene was found to be a useful solvent. The metal-enolate intermediate that results from the application of a Lewis acidic catalyst often cited as promoting the reaction appears to hinder the reaction. In this instance, a Brønsted acidic solvent can be used to return greater reactivity to the dicarbonyl reagent.
AB - The traditional Biginelli reaction is a three-component condensation between urea, benzaldehyde and an acetoacetate ester to give a dihydropyrimidinone. An investigation into catalytic and solvent effects has returned the conclusion that the diketo-enol tautomerisation equilibrium of the dicarbonyl reactant dictates the yield of the reaction. Whereas the solvent is responsible for the tautomerisation equilibrium position, the catalyst only serves to eliminate kinetic control from the reaction. Generally, to preserve reaction efficiency and improve sustainability, bio-derivable p-cymene was found to be a useful solvent. The metal-enolate intermediate that results from the application of a Lewis acidic catalyst often cited as promoting the reaction appears to hinder the reaction. In this instance, a Brønsted acidic solvent can be used to return greater reactivity to the dicarbonyl reagent.
UR - http://www.scopus.com/inward/record.url?scp=84877872716&partnerID=8YFLogxK
U2 - 10.1002/chem.201204396
DO - 10.1002/chem.201204396
M3 - Article
C2 - 23436300
SN - 0947-6539
VL - 19
SP - 5174
EP - 5182
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 16
ER -