Harnessing C-H acetoxylation: a gateway to oxygen-enriched organic frameworks

Transition metal catalyzed C-H functionalization has emerged as a robust tool in organic synthesis, as it utilizes the most abundant functional group of an organic compound, i.e. C-H bonds, omitting the need for pre-functionalization. Selectively functionalizing a particular C-H bond out of numerous C-H bonds present in the molecular skeleton is a fascinating and difficult task to perform. To differentiate between almost identical C-H bonds, various strategies have evolved. Directing group (DG) assistance, non-directed functionalizations, and non-covalent interactions have significantly contributed to addressing the challenge of regioselectivity in targeting distinct C-H bonds. However, further advancements are still required. Among various C-H functionalizations, C-H acetoxylation is a pivotal organic transformation which enables direct functionalization of otherwise inert C-H bonds into versatile acetoxy groups. In this review, various strategies for C-H acetoxylation, i.e. directed and non-directed C-H acetoxylation, electrochemical C-H acetoxylation, and photo-induced C-H acetoxylation, are covered. A comprehensive coverage provided by this review will be extremely useful to chemists in both academia and industry, who are striving to incorporate oxygen into organic molecular skeletons.