Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Department of Chemistry

Ionic Liquids

Ionic liquids (ILs) are organic salts being liquid at room temperature or at least below 100 °C and have been extensively used in organic synthesis. They possess a number of properties which makes them different from traditional organic solvents. In recent years, a great number of task-specific functional ionic liquids were synthesized for different purposes. We synthesized a series of guanidine based ILs and studied their effect on the catalytic performance in a number of reactions.


Catalysts for Aldol - Reactions

ionic liquids 1
ionic liquids 2

Catalysts for enantioselective Baylis - Hillmann - Reactions

ionic liquids 3

Catalysts for enatioselective Michael -Additon

ionic liquids 4
ionic liquids 5
ionic liquids 6

Selected Publications

Z. Yacob, J. Liebscher: "Chemistry of 1,2,3-Triazolium Salts"
Topics in Heterocyclic Chemistry, 2014, 40, 167-210

Zekarias Yacob, Jürgen Liebscher: "Synthesis and application of azolium ionic liquid tagged TADDOL catalysts"
Arkivoc 2012, (iii), 312-329

Jabbar Shah, Jürgen Liebscher: "Guanidinium-Tagged Organocatalysts for Direct Aldol Reactions"
Z. Naturforsch. B. 2011, 66b, 88-94

S. S. Khan, J. Shah, J. Liebscher: "Ionic-liquid tagged prolines as recyclable organocatalysts for enantioselective a-aminoxylations of carbonyl compounds"
Tetrahedron 2011, 67, 1812-1820

S. S. Khan, J. Liebscher: "Synthesis of New Dicationic Azolium Salts and Their Application as NHC Precursors in Suzuki-Miyaura Coupling"
Synthesis 2010,  2609-2615

S. S. Khan, J. Shah, J. Liebscher: "Synthesis of New Ionic-Liquid-Tagged Organocatalysts and Their Application in Stereoselective Direct Aldol Reactions"
Tetrahedron 2010, 66, 5082-5088

Jabbar Shah, Zekarias Yacob, Alexander Bunge, Jürgen Liebscher: "A New Dual Catalytic System for Asymmetric Morita-Baylis-Hillman Reaction"
Synlett 2010, 2079-2082

Sadaf S. Khan, Sven Hanelt, Jürgen Liebscher: "Versatile Synthesis of 1,2,3-Triazolium-based Ionic Liquids"
Arkivoc 2009, xii, 193 – 208

Jürgen Liebscher, Jabbar Shah, Zekarias Yacob, Sadaf Sadiq, Sven Hanelt, Haiko Blumenthal: "New ionic liquids as innovative reaction media"
J. Phys.: Conference Series 2009, 182, 012010

Jabbar Shah, Sadaf S. Khan, Haiko Blumenthal, Jürgen Liebscher: "1,2,3-Triazolium-Tagged Prolines and Their Application in Asymmetric Aldol and Michael Reactions "
Synthesis 2009, 23, 3975 – 3982

Jabbar Shah, Jürgen Liebscher "Synthesis of Chiral a-Amino Ester Derived Pentasubstituted Guanidines and Hexasubstituted Guanidinium Salts as Potential Ionic Liquids#8221;
Synthesis, 2008, 917-920

Jabbar Shah, Haiko Blumenthal, Zekarias Yacob, Jürgen Liebscher: "Proline catalyzed asymmetric aldol reactions in guanidine-derived ionic liquids"
Adv. Synth. Catal., 2008, 1267-1270

Zekarias Yacob, Jabbar Shah, Joachim Leistner, Jürgen Liebscher: "(S)-Pyrrolidin-2-ylmethyl-1,2,3-triazolium salts Ionic-Liquid-Supported Organocatalysts for Enantioselective Michael Addition to ß-Nitrostyrenes"
Synlett, 2008, 2342-2344