Premium
Electrogenerated N ‐Heterocyclic Carbenes in the Room Temperature Parent Ionic Liquid as an Efficient Medium for Transesterification/Acylation Reactions
Author(s) -
Chiarotto Isabella,
Feroci Marta,
Sotgiu Giovanni,
Inesi Achille
Publication year - 2013
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201201023
Subject(s) - ionic liquid , chemistry , transesterification , acylation , catalysis , alcohol , benzyl alcohol , organic chemistry , solvent , electrochemistry , electrode
N ‐Heterocyclic carbenes (NHCs), generated by electrochemical reduction under galvanostatic control of 1,3‐dialkylimidazolium‐based ionic liquids, were employed as catalysts in transesterification reactions in the parent, room temperature ionic liquids (RTILs) as solvents, without the utilisation of any volatile organic solvent or base. The reaction between isopropenyl or ethyl acetate and an alcohol (not efficient in the absence of catalyst) was induced by the presence of an electrogenerated NHC, which seems to assist the proton transfer from the alcohol to the ester, yielding the corresponding acetate. The reaction also proceeds with methyl nicotinate as starting ester and 2‐(diethylamino)ethanol or benzyl alcohol as alcohols and leads to the corresponding biologically active compounds, nicametate and benzyl nicotinate, in good yields. All products were isolated in good to excellent yields and complete recyclability of the ionic liquid as solvent has been demonstrated.