Recent Advances in Chalcogenation of <i>α</i>‐Amino Acids/Peptides: Synthetic and Mechanistic Aspects

Abstract Natural α ‐amino acids are building blocks of biomacromolecules proteins and peptides, which are essential for living organisms. Recently, structurally modified amino acids and their peptides have received high demand for the development of various types of biomaterials, including therapeutic drug candidates. For example, the chalcogenated amino acids and their peptides serve as privileged structural scaffolds, derived from native amino acids. Given the widespread utility of sulfur/selenium‐containing compounds in biological, pharmaceutical, and medicinal chemistry, efficient chalcogenation protocol has been accomplished through various catalytic methods such as transition‐metal, metal‐free, and photocatalytic strategies. Among them, transition‐metal based strategies through C−H activation have been extensively explored for the chalcogenation of amino acids and peptides. Concurrently, metal‐free and photocatalytic strategies offer sustainable and step‐economically viable pathways for achieving successful chalcogenation. In this review, we have focused on the recent achievements of both C(sp 2 )−H and C(sp 3 )−H chalcogenation of α ‐amino acids and peptides with chalcogenides along with their substrate scopes, mechanisms, advantages, and limitations.