α-Amino Acids: An Emerging Versatile Synthon in Visible Light-Driven Decarboxylative Transformations

a-Amino acids have been widely recognized as environmental-benign and non-fossil carbon sources both in biological and synthetic chemistry. In recent years, with the remarkable development of visible-light photocatalysis in organic synthesis, a-amino acid and its derivatives have received tremendous attention as radical precursors via photocatalyzed decarboxylation, thus realizing diverse aminoalkylated transformations or constructions of novel N-bearing heterocyclic motifs by taking advantage of N-atoms from a-amino acid. This review aims to provide a comprehensive update on the recent exploitation of a-amino acids in visible light photocatalysis, with particular emphasis on the types of a-amino acids employed and their distinct mechanisms applied wherein.