Pyridinyl Amide Ion Pairs as Lewis Base Organocatalysts
Julian Helberg, Torsten Ampßler, Hendrik Zipse
Abstract
Pyridinyl amide ion pairs carrying various electron-withdrawing substituents were synthesized with selected ammonium or phosphonium counterions. Compared to neutral pyridine-based organocatalysts, these new ion pair Lewis bases display superior catalytic reactivity in the reaction of isocyanates with alcohols and the aza-Morita–Baylis–Hillman reaction of hindered electrophiles. The high catalytic activity of ion pair catalysts appears to be due to their high Lewis basicities toward neutral electrophiles as quantified through quantum chemically calculated affinity data.
Topics & Concepts
ChemistryLewis acids and basesAmideBase (topology)IonCombinatorial chemistryPolymer chemistryOrganic chemistryCatalysisMathematical analysisMathematicsCoordination Chemistry and OrganometallicsSynthesis and characterization of novel inorganic/organometallic compoundsOrganometallic Complex Synthesis and Catalysis