Electrochemical and Photochemical Transformations of Tertiary Formamides

Compared with primary and secondary formamides, tertiary formamides are particularly difficult to activate due to the absence of N─H protons and increased steric hindrance around the nitrogen center. Traditionally, their transformation has relied heavily on stoichiometric oxidants or strong nucleophilic/electrophilic reagents. Over the past decade, the flourishing development of electrochemistry and photochemistry has provided entirely new paradigms for tertiary formamides transformation. This review systematically summarizes recent advances in electrochemical and photochemical‐promoted transformations of tertiary formamides. Based on the types of key intermediates generated and the roles they play, we classify these reactions into six categories: formation of acyl radicals; formation of aminyl radicals; formation of N ‐alkyl carbon‐centered radicals; formation of N ‐acyliminium ions; acting as nucleophiles; and acting as electrophiles. This framework elucidates the intrinsic connections among different reaction pathways and provides a clear trajectory for understanding the activation modes of tertiary formamides under electrochemical and photochemical conditions.