Site-Selective C-H Bond Activation/Functionalization of Alpha-Amino Acids and Peptide-Like Derivatives

Amino acids and peptides play an important role in nature, as well as in organic and pharmaceutical chemistry. Therefore, the easy, straightforward and versatile access of biogenic and unnatural derivatives is still highly demanding. This micro-review intends to provide to the reader the current state of the art on site-selective C-H bond functionalization technology applied on alpha-amino acids and peptides, focusing on the different C-H positions that can successfully be addressed to date. It is structured in two main parts implying i) the alpha-C-H functionalization at the peptide backbone and ii) the modification of the side-chain. Herein, metal-catalyzed C-H activation, oxidative C-H functionalization, as well as light mediated approaches, are discussed considering the challenges in reactivity and selectivity. The great potential of these transformations is also depicted with the derivatization and macrocyclization of complex peptides leading to products of pharmaceutical importance.