6533b7ddfe1ef96bd1273f73

RESEARCH PRODUCT

Functionalised diimidazolium salts: the anion effect on the catalytic ability

Francesca D'annaCarla RizzoRenato Noto

subject

010405 organic chemistryGeneral Chemical EngineeringSettore CHIM/06 - Chimica OrganicaGeneral Chemistry010402 general chemistry01 natural sciencesIonic Liquids Michael Reaction Base catalysis0104 chemical sciencesCatalysisIonchemistry.chemical_compoundchemistryIonic liquidPolymer chemistryMichael reactionOrganic chemistryBenzeneMalononitrile

description

The catalytic ability of some functionalised diimidazolium ionic liquids was tested using the Michael addition of malononitrile to t-chalcone as probe reaction. Diimidazolium salts characterized by the presence of 1-(1-imidazolylmethyl)-3,5-di-[1-(3-octylimidazolylmethyl)]benzene cation and differing in the anion structure were used. Both mono- and dianions were employed and among these some chiral anions generally used as organocatalysts were taken into account. Data collected were analysed both as function of ionic liquids structure and basicity, evaluated using the Hammett basicity function. Although the use of chiral anions did not allow performing a stereochemical control of the reaction, data collected demonstrate the high catalytic ability of the functionalised salts. Indeed, high conversions and yields were obtained under mild conditions and in significantly shorter reaction times with respect to the ones so far reported for this reaction.

https://doi.org/10.1039/c6ra12037g