Assembly of Amino Acid Derivatives via Energy Transfer-Driven Photochemical Rearrangement

The development of synthetic methods to access amino acid derivatives remains a high priority. Herein, we report a photocatalytic strategy based on triplet energy transfer that drives a photochemical rearrangement to furnish diverse amino acid derivatives bearing epoxide functionality in good yields. This operationally simple protocol employs a commercially available organophotocatalyst and visible-light irradiation. Mechanistic and computational studies corroborate a reaction pathway involving diradical formation, a 1,4-nitrogen migration, and a 1,3-diradical recombination. This oxa-di-π-methane (ODPM) rearrangement provides a route to unnatural amino acid scaffolds and establishes a direction for energy-transfer-driven photochemical synthesis.