On the mechanism of sp2 C–H borylation using ortho-N-substituted pyridinium cations

Nikita Slesarchuk, Enlu Ma, Juan Miranda Pizarro, Sami Heikkinen, Dieter Shollmeyer, Martin Nieger, Petra Satu Päivikki Vasko, Timo Repo

Research output: Contribution to journalArticleScientificpeer-review

Abstract

ortho-N-Substituted pyridinium cations with the weakly coordinating anion [B(C6F5)4]− have been studied and crucial structural features in the sp2 C–H borylation catalysis of 3-methylthiophene have been identified. The electron-deficiency of the aromatic core of the cation is essential for activity together with accessible protons. The spectroscopic yield of the borylation of 3-methylthiophene with catecholborane (CatBH) was optimized up to 86% and the method was further applied to other substrates such as N-alkylbenzenes. A mechanistic DFT study revealed the rate-limiting step in the catalysis to be the liberation of molecular H2 (ΔG‡ = 27.5 kcal mol−1), whereas the overall reaction was found to be exergonic by 5.1 kcal mol−1.
Original languageEnglish
JournalDalton Transactions
Number of pages6
ISSN1477-9226
DOIs
Publication statusPublished - 6 May 2024
MoE publication typeA1 Journal article-refereed

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