A strategy to access unprecedented reactive intermediates featuring carbenes, carbocations, biradicals, and inverted σ-bonds via hypervalent λ³-haloganes

Abstract

High-energy precursors can provide access to highly labile reactive intermediates, enabling unprecedented transformations under mild conditions. This review highlights a series of hypervalent λ³-haloganes, focusing on the λ³-iodanyl, λ³-bromanyl, and λ³-chloranyl groups as hypernucleofugic leaving groups. We also summarize recent studies on the generation and chemical reactivity of diatomic carbon (C₂) and m-benzyne, which can be best described as highly stabilized singlet biradicals.