The search for selective C–H functionalisation has enabled some of the most elegant techniques in modern catalysis. Herein, we review the rapidly expanding field of ruthenium catalysed σ-activation as a tool in the selective meta-C–H functionalisation of arenes.

The rhodium catalysed conjugate addition of organometallics to activated alkenes is a powerful synthetic tool for establishing new carbon–carbon bonds often with high stereoselectivity. The introduction of a practical, efficient method for introducing functionalised aryl and alkenyl fragments with predictable stereocontrol has caught the attention of synthetic chemists and emerging examples are growing in number and complexity. In this tutorial review, we document notable advances in the application of rhodium catalysed conjugate addition processes within the context of synthesis of complex molecules and intermediates in drug discovery. The chosen examples illustrate important issues regarding scope, selectivity and reactivity that will help guide the selection of appropriate donor and acceptor to achieve the desired carbon–carbon bond construction when planning new synthetic routes.