Transient ligand‐enabled transition metal‐catalysed C‐H functionalisation

Abstract

Transition metal‐catalysed C‐H bond functionalisation is one of the most efficient and powerful strategies in synthetic organic chemistry to derivatize otherwise inert sites of organic molecules for the construction of C‐C and C‐heteroatom bonds. However, additional steps are often required in order to install the directing groups to realize the positional functionalisation of the substrates. These tedious steps run counter to the step‐economical nature of the C‐H activation. In contrast, direct functionalisation of the substrate, utilizing the transient ligands, avoids the unnecessary steps for the prefunctionalisation of the substrates. In this mini review, we will provide a short journey for the major progress made in this field for the C‐H functionalisation on sp2 and sp3 carbon centres with different transient working modes, including the covalent, hydrogen, and ionic bonds.