C(sp ² )H Functionalization Guided by Intrinsic Functional Groups

Abstract

CH activation has proven to be one of the most versatile synthetic strategies developed so far for the functionalization of sp 2 centers, due to the large variety of reaction conditions available to the practitioner including choice of catalyst, oxidant, additives and also directing group. Regarding the latter, one possibility is to use an intrinsic directing group. These are functional groups resident in the substrate containing a pair of nonbonding electrons, which can interact with the metal center of a catalyst and therefore control the site of CH activation. The use of a directing group that is intrinsic to the molecule is advantageous, as additional synthetic steps are not required for its installation and removal. The implementation of this directing group strategy is therefore guided by the structure of the desired compound and the coordinating ability of heteroatoms within it.