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Updated: Dec 25, 2025

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
Published on: February 20, 2020
Pyridinyl Amide Ion Pairs as Lewis Base Organocatalysts
Julian Helberg1, Torsten Ampßler1, Hendrik Zipse1
1Department of Chemistry, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377 München, Germany.
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.
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