Spieß P,
Berger M,
Kaiser D,
Maulide N.
*
University of Vienna, Austria
Direct Synthesis of Enamides via Electrophilic Activation of Amides.
J. Am. Chem. Soc. 2021;
143: 10524-10529
Key words
electrophilic activation - enamides - lithium bis(trimethylsilyl)amide
Significance
The authors report the direct synthesis of enamides from amides. Tf2O is used for the electrophilic activation of amides as well as an oxidant in the reaction. The products are obtained in moderate to good yields and a range of functional groups are tolerated by the procedure. Gram-scale reactions also proved to be successful.
Comment
To show the utility of the procedure, several downstream reactions were conducted including cycloadditions, ring functionalizations and ring deconstructions. A mechanism based on experimental studies is proposed. The proton next to the nitrogen is thereby acidified by the cationic nature of the activated iminium triflate intermediate.
