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Updated: Jan 5, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Efficient and Divergent Synthesis of α-Halogenated Amides and Esters by Double Electrophilic Activation of Ynamides
Pierre Thilmany1, Gwilherm Evano1
1Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50, CP160/06, 1050, Brussels, Belgium.
Abstract:
An efficient and modular entry to α-halogenated amides and esters is reported. This reaction is based on an underestimated double electrophilic activation of ynamides sequentially involving highly reactive activated keteniminium and iminium ions. Upon simple reaction with HCl and an electrophilic halogenation reagent in the presence of water or an alcohol, a broad range of ynamides can be transformed, in a highly divergent manner, to α-halo amides and esters with high efficiency and under mild conditions.
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