Direct Nucleophilic Substitution of Alcohols by Brønsted or Lewis Acids Activation: An Update

Typically substitution of alcohols involves a two-step activation/displacement pathway thus leading to the generation of additional waste. The current chapter considers an alternative reaction manifold with the displacement taking place directly through activation of the alcohol by either a Lewis or Brønsted acid. With particular focus on the literature since 2011, an initial overview of carbenium ion reactivity is provided followed by a survey of displacement reactions grouped by the nature of the nucleophile. Finally, advances in both diastereoselective and enantioselective variants of the reaction are discussed.