American Chemical Society
cs7b00562_si_001.pdf (7.77 MB)

Tertiary Amine-Derived Ionic Liquid-Supported Squaramide as a Recyclable Organocatalyst for Noncovalent “On Water” Catalysis

Download (7.77 MB)
journal contribution
posted on 2017-03-16, 00:00 authored by Rinat S. Tukhvatshin, Alexander S. Kucherenko, Yulia V. Nelyubina, Sergei G. Zlotin
Chiral tertiary amine-derived ionic liquid-supported squaramide was synthesized from available precursors and applied as an efficient organocatalyst for asymmetric Michael additions of β-dicarbonyl compounds to α-nitroolefins in the presence of water. Corresponding Michael adducts were generated under proposed conditions in nearly quantitative yield with high enantioselectivity (up to 99% ee). Useful precursors to pharmaceutically important chiral β-amino acids and anticonvulsant Pregabalin were conveniently prepared using the developed “on water” protocol. The catalyst is readily recoverable and reusable over 30 times without a significant decrease of catalytic reaction activity and selectivity.