I₂‑Catalyzed Aerobic α,β-Dehydrogenation and Deamination of Tertiary Alkylamines: Highly Selective Synthesis of Polysubstituted Pyrimidines via Hidden Acyclic Enamines

A novel and efficient entrance to the pyrimidine skeleton has been presented via the α,β-dehydrogenation and deamination of tertiary alkylamines. This I₂-catalyzed dehydrogenative multicomponent procedure utilizes simple aldehydes to trap the hidden enamine intermediates and suspend generation of azadienes from amidines, enabling the difunctionalization of a vicinal C­(sp³)–H bond. These studies provide valuable possibilities for the introduction of aliphatic substituents and show how to switch to a new reactive modality.