These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Chemtob-Preprint-v3.pdf (929 kB)

Photochemically Activated Thiol-Michael Reactions via a Photolatent N-Heterocyclic Carbene

submitted on 02.10.2019, 16:33 and posted on 04.10.2019, 22:17 by Abraham Chemtob, Bao Tram Vu Ngoc, Julien Pinaud, Patrick Lacroix-Desmazes, Valérie Héroguez

While N-heterocyclic carbenes (NHCs) have proven highly effective in various polymerization reactions, the drawback is their high sensitivity towards air and water, which necessitates handling under rigorously anhydrous conditions. In this report, an air-stable two-component NHC photogenerator ─ 2-isopropylthioxanthone (ITX) as photosensitive species and 1,3-bis(mesityl)imidazolium tetraphenylborate (IMesH+ BPh4-) acting as NHC protected precursor ─ has been utilized to organocatalyze thiol-Michael reaction for small molecule and polymer synthesis. The feasibility of photoNHC catalysis in addition reactions involving thiol and ene molecules was investigated using 1H NMR spectroscopy. The synthesis of cross-linked polythioether polymer via a step-growth polymerization was then studied using FTIR spectroscopy, optical pyrometry and gel content measurements.


French National Research Agency (ANR program: DS0304 2016, contract number: ANR-16-CE07-0016)


Email Address of Submitting Author


Institut de Science des Matériaux de Mulhouse (IS2M) UMR 7361 - CNRS/UHA



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest to declare

Version Notes

Version n°1