Removal and modification of directing groups used in metal-catalyzed C-H functionalization: the magical step of conversion into 'conventional' functional groups.

Over the past few decades, regioselective catalytic C-H functionalization has provided an attractive tool for unique retrosynthetic disconnections. The advancement of the directing group strategy in metal catalyzed synthetic transformation has contributed significantly to the incorporation of a wide range of functionalization reactions in both aromatic systems and aliphatic backbones. However, the extensive utilization of these methodologies depends on the ease of removal of the directing group to restore the free functional group. In this review, we have summarised the reported approaches for removing/modifying versatile directing groups.