Über β‐Lactame, IV¹. Über die Halogenierung von 1‐Diäthylamino‐2‐phthalimido‐1‐aryl‐äthylenen

Nucleophilic Addition of Amides to Haloalkynes: Synthesis of (Z)-β-Halovinyl Amides as Dual Precursors of Alkylidene Carbenes and Allyl Halides

“…β-Halovinyl amides are reactive precursors , whose enamide-based structure − exhibits additional reactivity upon functionalization with halogen atoms. They are used in diverse reactions, such as cross-coupling reactions , and substitution reactions for the elucidation of original reactivity, , as well as for the preparation of natural products, − unnatural amino acids, − N -Heterocyclic compounds, ,− and fluorescent materials. , The preparation of β-halovinyl amides is generally conducted via halogenation of enamides ,,,− or amination of bromoketoesters; however, these methods proceed with insufficient regioselectivity (Figure A). This issue was overcome by the Miossec group, who established a practical regioselective method to prepare β-halovinyl amides from l -serine via dehydroxylation and regioselective halogenation (Figure A, upper row). , Recently, new protocols to prepare β-halovinyl amides were developed, such as halogenation of β-silylenamides, cross-coupling of carbamates with diiodoalkenes (Figure B), , and amination of bromotrichlorobutenones (Figure C) .…”