Water, Alcohols, Amines, and Amides as Formal Hydrogen‐Atom‐Transfer Reagents Through Activation With Redox‐Active Lewis Acids

Abstract

ABSTRACT The O─H and N─H bonds of protic molecules such as water, alcohols, amines, or amides typically resist hydrogen‐atom abstraction because of the high energy of the resulting heteroatom‐centered radical intermediates. However, association of the protic molecules with redox‐active Lewis acids provides stabilization of the generated reactive radical intermediates and enables the ligated protic molecules to serve as hydrogen‐atom donors or proton‐coupled‐electron‐transfer reagents. This review presents an overview of applications of this bond‐weakening principle in organic synthesis and attempts to illustrate the breadth of systems that enable such reactivity.