Acidity Scale of N-Heterocyclic Carbene Precursors: Can We Predict the Stability of NHC-CO2 Adducts?

Zhen Wang; Fang Wang; Xiao-Song Xue; Pengju Ji

doi:10.1021/acs.orglett.8b02290

Acidity Scale of N-Heterocyclic Carbene Precursors: Can We Predict the Stability of NHC-CO₂ Adducts?

Org Lett. 2018 Oct 5;20(19):6041-6045. doi: 10.1021/acs.orglett.8b02290. Epub 2018 Sep 14.

Authors

Zhen Wang^{1

2}, Fang Wang¹, Xiao-Song Xue^{1

2}, Pengju Ji³

Affiliations

¹ School of Chemical and Environmental Engineering , Anyang Institute of Technology , Anyang 455000 , China.
² State Key Laboratory on Elemento-organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China.
³ Center of Basic Molecular Science (CBMS), Department of Chemistry , Tsinghua University , Beijing 100084 , China.

PMID: 30216083
DOI: 10.1021/acs.orglett.8b02290

Abstract

The acidity scale (∼14 p K units) of more than 90 triazolium, imidazolium, and imidazolinium based NHC precursors in DMSO was established systematically by a well-developed computational model. The substituent effects on the acidities of these NHC precursors were analyzed through acidity comparison and Hammett correlation. The binding energy (Δ G₁) of the reaction between NHC and CO₂ was also calculated and linearly correlates with the basicity of the corresponding NHC, which implies that the stability of the NHC-CO₂ adduct is essentially dictated by the basicity of NHC.

Publication types

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