Electrostatic effects in N-heterocyclic carbene catalysis: revealing the nature of catalysed decarboxylation

Quantum chemistry is used to investigate the nature of protonated N-heterocyclic carbene (NHC center dot H+) catalysed decarboxylation recently reported by Zhang et al. (ACS Catal., 2021, 11, 3443-3454). Our results show that there are strong electrostatic effects within the NHC center dot H+ catalysed decarboxylation, and these dominate hydrogen bonding. At the same time, energy decomposition analyses and comparison between the original NHC center dot H+ catalyst and a truncated form reveal that stabilizing dispersion interactions are also critical, as is induction. We also show that the electrostatic effects and their associated catalytic effects can be further enhanced using charged functional groups.

Automated summary

This study reveals the strong electrostatic effects and stabilizing dispersion interactions in the NHC center dot H+ catalyzed decarboxylation reaction. Additionally, charged functional groups are shown to enhance the electrostatic effects and catalytic effects even further.