Abstract
The aim of this Short Review is to give an updated overview of the synthesis of α-haloenamides, which constitute a versatile subclass of enamides. α-Haloenamides can be prepared from ynamides, acetamides, or gem-dibromoalkenes in the presence of N-nucleophiles and easily converted into more elaborated structures through halogen-metal exchange and transition-metal-catalyzed cross-coupling reactions.
1 Introduction
2 α-Haloenamide Synthesis
2.1 Hydrohalogenation of Ynamides
2.1.1 cis-Hydrohalogenation of Ynamides
2.1.2 trans-Hydrohalogenation of Ynamides
2.2 α,β-Dihalogenation
2.2.1 lodochlorination and Iodobromination of Ynamides
2.2.2 Iodofluorination of Ynamides
2.3 Chloroselenation of Ynamides
2.4 Carbohalogenation of Ynamides
2.4.1 Carboiodination
2.4.2 Chloroallylation
2.4.3 Chloro-benzhydrylation
2.4.4 Chloro-γ-hydroxylation
2.5 Vilsmeier–Haack Reactions
2.6 Cross-Coupling Reaction of gem-Dibromoalkenes in the Presence of N-Nucleophiles
3 Transformations of α-Haloenamides
3.1 Suzuki and Sonogashira Reactions
3.2 Heck Reaction
3.3 Stille Reaction
3.4 Miscellaneous Applications
3.4 Carbonylation
3.4.2 Reduction
3.4.3 Synthesis of α-Fluoroimides
3.4.4 Palladium-Catalyzed Intramolecular Cyclization
4 Conclusion
Key words
α-haloenamides - synthesis - ynamides - halogenation - cross-coupling reactions
