Distillable ionic liquids for a new multicomponent reaction*
Anthony E. Rosamilia1, Christopher R. Strauss2, and Janet L. Scott1
1Centre for Green Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia; 2Strauss Consulting Pty Ltd., P.O. Box 1065, Kunyung LPO, Mt. Eliza, Victoria, Australia
Abstract: Adducts of dimethylamine and carbon dioxide form a "distillable ionic liquid" (DIMCARB) that may used as both a reaction medium and catalyst in the direct, atom-economical synthesis of useful synthetic building blocks, such as mono-condensed α,β-unsaturated ketones. The utilization of such building blocks in the synthesis of two new classes of versatile macrocycles, by a sequence of condensation reactions (H2O by-product), is described. Investigation into the mechanism of action of DIMCARB catalysis and observation of an aniline impurity arising from a competing reaction sequence led to development of a new multicomponent reaction for the direct preparation of 2- or 4-substituted anilines. Some of the macrocycles and anilines are, respectively, supramolecular host compounds and ligands for the preparation of metal complexes.
Keywords: ionic liquids; green chemistry; sustainability; DIMCARB; substituted anilines.
*Pure Appl. Chem. 79, 1831-2100. An issue of reviews and research papers based on lectures presented at the 1st International IUPAC Conference on Green-Sustainable Chemistry, held in Dresden, Germany, 10-15 September 2006.