title: Ionic liquids as precatalysts in the highly stereoselective conjugate addition of α,β-unsaturated aldehydes to chalcones.
abstract: Imidazolium-based ionic liquids (ILs) serve both as recyclable reaction media and as precatalysts for the N-heterocyclic carbene-catalyzed conjugate addition of α,β-unsaturated aldehydes to chalcones. The reaction produces a broad scope of 1,6-ketoesters incorporating an anti-diphenyl moiety in high yields and with high stereoselectivity. In recycling experiments, the IL can be reused up to five times with retained reactivity and selectivity. Moreover, the 1,6-ketoesters form self-assembled organogels in aliphatic hydrocarbons. The reaction protocol is robust, easily operated, scalable and highly functionalized compounds can be obtained from inexpensive and readily accessible starting materials.
authors.affiliation: Chemistry and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg (Sweden).
authors.forename: Linda
authors.initials: L
authors.lastname: Ta
authors.forename: Anton
authors.initials: A
authors.lastname: Axelsson
authors.forename: Joachim
authors.initials: J
authors.lastname: Bijl
authors.forename: Matti
authors.initials: M
authors.lastname: Haukka
authors.forename: Henrik
authors.initials: H
authors.lastname: Sundén
keywords: NHC; green chemistry; ionic liquids; ketoesters; organogels