A highly versatile method for the preparation of enantiopure 1-substituted, 1,2-disubstituted, and 1,4,5-trisubstituted imidazoles was developed by using the cyclocondensation reaction of a 1,2-dicarbonyl compound, an aldehyde, a 1,2-amino alcohol, and ammonium acetate.
An imidazolium-based ionic liquid with cyclophane-type planar chirality was synthesized in an optically pure form for the first time. The resultant ionic liquid existed as a liquid at room temperature (T-g = -35 degrees C), and was found to be applicable as an NMR chiral shift reagent for racemic anions. Excellent robustness of the ionic liquid to a highly elevated temperature (270 degrees C) was proved from the viewpoints of isomerization and thermal decomposition. (c) 2006 Elsevier Ltd. All rights reserved.