FLP-Mediated C–H-Activation

Abstract

The C–H functionalization of aromatic molecules is a green approach that allows creating complex molecules from simple reagents. While these transformations are mainly catalysed using transition metalTransition metal complexes, the main group molecules, including frustrated Lewis pairsFrustrated Lewis pair (FLP), have been shown to be efficient species to functionalize C–H bonds. This chapter describes the different approaches and mechanisms that are used to activate C–H bonds using Lewis acidic boron and silicon species. On the one hand, highly electrophilic cationic boron and silicon species can activate C–H bonds by an electrophilic additionElectrophilic addition pathway that generates a Wheland intermediate that is further deprotonated by a Lewis baseLewis base. On the other hand, frustrated Lewis pairsFrustrated Lewis pair (FLP) act in a concerted way where the Lewis acidLewis acid activation and the deprotonation by a base occur simultaneously. In both systems, the nature of the Lewis acidLewis acid and Lewis baseLewis base plays an important role on the activity and the selectivity of the functionalization reaction.