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Updated: Nov 1, 2025

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Correlations between Substituent Effects and Catalytic Activities: A Quantitative Approach for the Development of
Norie Momiyama1,2, Atsuto Izumiseki1,2, Naoya Ohtsuka1,2
1Institute for Molecular Science, Okazaki, Aichi, 444-8787, Japan.
Abstract:
A quantitative approach for the development of halogen-bonding-driven anion-binding catalysts was studied using 4-substituted perfluorinated iodobenzene. 19 F NMR titrations were used to determine the binding constants K for chloride, and their catalytic activities were evaluated in the allylation reaction of a N-activated pyridine. We discovered that the log K and product yields were linearly correlated, and that they were dependent on the Hammett substituent parameter, σmeta (r2 =0.99). This linear correlation provided a quantitative predictive model for both the binding constant and the reaction yield. Concomitantly, this efficiently permitted the development of a highly active anion-binding catalyst, namely 4-CNC6 F4 I (K=489±5 M-1 ). Additionally, the catalytic activity of 4-CNC6 F4 I was established in the allylation and crotylation of N-activated isoquinolines (7 examples). Overall, this approach highlights the value of quantitative analysis by exploring experimentally informed correlations in the development of halogen bond donor catalysts.
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