Diaryl hypervalent bromines and chlorines: synthesis, structures and reactivities

Abstract

Diaryl hypervalent bromines and chlorines emerge as a novel foundation for advancing organic chemistry. This article provides an overview of the synthetic methodology, structural variations, and the latest transformations unearthed in this context.

Halogen, Chalcogen, Pnictogen, and Tetrel Bonding in Non‐Covalent Organocatalysis: An Update

“…Unlike iodonium salts, research on bromonium reagents has been relatively limited. [72] They are less stable towards nucleophiles [73] and computational analyses indicated a lower Lewis acidity compared to iodolia. [74] Nonetheless, novel cyclic diarylbromonium salts 20 were synthesized by Yoshida and were successfully used for the first time as XB catalysts in a Michael reaction (Scheme 8).…”

Nichtkovalente Organokatalyse mit Halogen‐, Chalkogen‐, Pniktogen‐ und Tetrelbrücken: neuere Entwicklungen

“…Im Gegensatz zu Iodoniumsalzen war die Forschung zu Bromoniumreagenzien bisher relativ begrenzt. [72] Diese sind weniger stabil gegenüber Nukleophilen [73] und computerchemische Analysen zeigen eine verringerte Lewis-Azidität im Vergleich mit Iodolia. [74] Nichtsdestotrotz wurden die neuartigen cyclischen Diarylbromoniumsalze 20 von Yoshida synthetisiert und erstmals erfolgreich als XB-Katalysatoren in einer Michael-Reaktion eingesetzt (Schema 8).…”

Easy access to polyhalogenated biaryls: regioselective (di)halogenation of hypervalent bromines and chlorines

“…These unusual reagents, which are safe to handle and easy to prepare ( Scheme 1C ), undergo unexpected metal-free cycloadditions and meta -functionalizations with C-, O- and N-nucleophiles though in situ aryne formation at room temperature. 12 …”