Enamide Derivatives: Versatile Building Blocks for Highly Functionalized α,β-Substituted Amines

As demonstrated by earlier successes with enamines, nitrogen-activated C=C double bonds have considerable potential for use in the construction of various nitrogen-containing products. To expand the applications of this class of substrates, we focused on studying the reactivity of enamides and enecarbamates as promising representatives. Starting from the well-known Povarov reaction, we gradually developed other cycloaddition reactions and, more generally, an extended range of methods for ,-difunctionalization. Our most recent work, which involves radical processes, has contributed to a significant increase in the diversity of scaffolds accessible from these nitrogenous substrates and is potentially applicable to various natural and bioactive synthetic targets. 1Introduction 2General Design 3Asymmetric BrOnsted Acid-Catalyzed ,-Difunctionalization of Enamides 3.1Intramolecular ,-Difunctionalization of Enamides Through Cycloaddition Reactions 3.1.1Povarov Reactions 3.1.2Diels-Alder Reactions of 1-Azadienes 3.2Intermolecular ,-Difunctionalization of Enamides 3.2.1Mannich Reactions 3.2.2Addition to Azo Compounds 3.2.3Halogenation Reactions 4Radical Tandem Difunctionalization: -Alkylation Followed by -Functionalization of Enamides 4.1Photoredox-Mediated Tandem ,-Difunctionalization of Enamides 4.1.1Oxyalkylation 4.1.2Oxy-, Amino- and Carbotrifluoromethylation 4.2Single-Electron Transfer-Mediated Tandem ,-Difunctionalization of Enamides 5Conclusion