This Account is dedicated to the memory of Keith Fagnou.
Abstract
Catalytic C–H activation reactions are now established as a means to directly transform organic molecules and are commonly associated with metals such as palladium, rhodium, ruthenium and iridium. This Account will describe a short number of reports demonstrating that structures containing main group elements can facilitate C–H activation processes. In particular, boron-based catalysts can promote catalytic arene C–H borylation reactions, and an emerging approach using phosphenium ions can also cleave sp2 C–H bonds. These processes use a Lewis acidic main group atom combined with a pendant base to cleave C–H bonds, which compares with metal-catalyzed reactions that proceed via concerted metalation deprotonation mechanisms.
1 Introduction
2 Metal-Catalyzed C–H Activation via CMD/AMLA Mechanisms
3 C–H Borylation via Boron-Based Catalysts
4 C–H Activation Using Phosphenium Ions
5 Conclusions
Key words
C–H activation - main group catalysis - concerted metalation–deprotonation - borylation - phosphenium ions