Basic chiral ionic liquids: A novel strategy for acid-free organocatalysis

• DOI: 10.1016/j.cattod.2012.07.002
• Publication Date: 2012-08-10T12:31:55Z
• Authors: Maria Vasiloiu; Daniel Rainer; Peter Gaertner; Christian Reichel; Christian Schröder; Katharina Bica
• Keywords: 104015 Organische Chemie; 104017 Physical chemistry; 104015 Organic chemistry; 01 natural sciences; 104017 Physikalische Chemie; 0104 chemical sciences

We present design, synthesis and application of basic chiral ionic liquids based on commercially available (S)-proline. This new set of chiral ionic liquids was specifically designed to replace trifluoroacetic acid in enamine-based organocatalysis for asymmetric C-C bond formation. Based on their permanent charge, these chiral ionic liquids could be applied as organocatalysts in asymmetric aldol reaction of 4-nitrobenzaldehyde and acetone, and good yields and selectivities up to 80%ee could be obtained without additional acid.