N-Bromosuccinimide (NBS) is the standard reagent for allylic and benzylic bromination. Which of the — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

A) True. The mechanism relies on traces of $HBr$ reacting with NBS ($NBS + HBr \rightarrow Succinimide + Br_2$) to supply a tiny but constant stream of $Br_2$. B) True. Electrophilic addition across a double bond requires a relatively high localized concentration of $Br_2$ to form the bridged bromonium ion. At very low $Br_2$ concentrations, the allylic radical easily abstracts a $Br$ atom from $Br_2$, keeping the chain reaction viable and suppressing addition. C) False. The reaction is entirely a free-radical process initiated by light or peroxides, not electrophilic. D) False. Succinimide is merely a byproduct and plays no active protective role.