In 2022,Wu, Terence; Tatton, Matthew R.; Greaney, Michael F. published an article in Angewandte Chemie, International Edition. The title of the article was 《NHC Catalysis for Umpolung Pyridinium Alkylation via Deoxy-Breslow Intermediates》.Safety of Pyridin-3-ylboronic acid The author mentioned the following in the article:
Umpolung N-heterocyclic carbene (NHC) catalysis of non-aldehyde substrates offers new pathways for CC bond formation, but has proven challenging to develop in terms of viable substrate classes. Here, the authors demonstrate that pyridinium ions can undergo NHC addition and subsequent intramol. C-C bond formation through a deoxy-Breslow intermediate. The alkylation demonstrates, for the first time, that deoxy-Breslow intermediates are viable for catalytic umpolung of areniums. In the part of experimental materials, we found many familiar compounds, such as Pyridin-3-ylboronic acid(cas: 1692-25-7Safety of Pyridin-3-ylboronic acid)
Pyridin-3-ylboronic acid(cas: 1692-25-7) belongs to pyridine. Pyridines form stable salts with strong acids. Pyridine itself is often used to neutralize acid formed in a reaction and as a basic solvent. Safety of Pyridin-3-ylboronic acid