How Attractive is Bromine as a Protecting Group in Aromatic Chemistry?

Abstract

The reversibility of electrophilic bromination of aromatic compounds has been known for a long time, but the possibility of using bromine as a protecting group in aromatic or heterocyclic chemistry has now been shown for the first time (see scheme for an example). Compared with typical protective groups (SO3H, COOH, NH2, CHMe2, CMe3) bromine offers many advantages; a decisive aspect for its successful application is the choice of optimized reaction conditions which are predictable from the reaction mechanism.