Copper in CH Functionalization: Mechanistic Insights into CH to CC/N/O Transformations

Abstract This article illustrates a diverse array of copper‐mediated CH to CX (X = C/N/O) transformations. Moreover, the examples are discussed to underscore the possible copper‐containing intermediates by emphasizing the routes for the generation of the catalytically viable intermediates and their reactivity trends relevant to CH to CX transformations. In contrast to the organometallic pathways commonly preferred by the 2nd and 3rd row transition metal‐catalyzed CH to CX (X = C/N/O) transforming routes, the routes involving copper sites have been illustrated to involve both organometallic as well as outer sphere mechanisms. Consequently, the copper‐mediated CH functionalization routes utilize a combination of both 1e‐ and 2e‐ steps. Thus, a detailed understanding of the mechanism is critical for the rational design of the catalyst as well as the methods.