Carbon-Hydrogen bonds are the most common bonds that occur in organic chemistry, they’re generally very strong, and unreactive. Because of the high dissociation energy associated with C-H bond activation ( the C-H bond dissociation in alkanes is 2.2-2.7 (V vs SHE)), molecules already containing functional groups will have them react at lower potentials, rendering late stage C-H functionalization useless. Chemical C-H activation is difficult to achieve, especially with C(sp3)-H bonds, it is expensive and associated with generation of a lot of waste.
Functionalization of inert carbon-hydrogen (C-H) bonds is an important reaction in the chemical industry. The introduction of functional groups (e.g. oxygen, nitrogen, sulfur, … atom) in otherwise inert molecules is necessary to construct more complex molecules for the bulk and fine chemicals industry.