Alcohols as substrates in transition metal-catalyzed arylation, alkylation and related reactions

Alcohols are abundant and attractive feedstock molecules for organic synthesis. Many methods for their functionalization require them to first be converted into a more activated derivative, while recent years have seen a vast increase in the number of complexity-building transformations that directly harness unprotected alcohols. This review discusses how transition metal catalysis can be used towards this goal. These transformations are broadly classified into three categories. Etherifications, characterized by derivatization of the O–H bond, represent classical reactivity that has been modernized to include mild reactions conditions, diverse reaction partners, and high selectivities. Deoxygenative functionalizations, representing derivatization of the C–O bond, enable the alcohol to act as a leaving group towards the formation of new C–C bonds. Lastly, chain functionalization reactions are described, wherein the alcohol group acts as a mediator in formal C–H functionalization reactions of the alkyl backbone. Each of these three classes of transformation will be discussed in context of intermolecular alkylation, arylation, and related reactions, illustrating how catalysis can enable alcohols to be directly harnessed for organic synthesis.