Selective Hydroxylation of C(sp3)−H Bonds in Steroids

Steroids are highly prevalent structures in small-molecule therapeutics, with the level of oxidation being key to their biological activity and physicochemical properties. These C(sp³ )-rich tetracycles contain many stereocentres, which are important for creating specific vectors and protein binding orientations. Therefore, the ability to hydroxylate steroids with a high degree of regio-, chemo- and stereoselectivity is essential for researchers working in this field. This review will cover three main methods for the hydroxylation of steroidal C(sp³ )-H bonds: biocatalysis, metal-catalysed C-H hydroxylation and organic oxidants, such as dioxiranes and oxaziridines.