NMR Quantification of Halogen-Bonding Ability To Evaluate Catalyst Activity

Yun-Pu Chang; Teresa Tang; Jake R Jagannathan; Nadia Hirbawi; Shaoming Sun; Jonah Brown; Annaliese K Franz

doi:10.1021/acs.orglett.0c02427

NMR Quantification of Halogen-Bonding Ability To Evaluate Catalyst Activity

Org Lett. 2020 Aug 21;22(16):6647-6652. doi: 10.1021/acs.orglett.0c02427. Epub 2020 Aug 3.

Authors

Yun-Pu Chang¹, Teresa Tang¹, Jake R Jagannathan¹, Nadia Hirbawi¹, Shaoming Sun¹, Jonah Brown¹, Annaliese K Franz¹

Affiliation

¹ Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, United States.

PMID: 32806211
DOI: 10.1021/acs.orglett.0c02427

Abstract

Quantification of halogen-bonding abilities is described for a series of benzimidazolium-, imidazolium- and bis(imidazolium) halogen-bond donors (XBDs) using ³¹P NMR spectroscopy. The measured Δδ(³¹P) values correlate with calculated activation free energy ΔG^‡ and catalytic activity for a Friedel-Crafts indole addition. This rapid method also serves as a sensitive indicator for Brønsted acid impurities.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't