A Strategy for Amide to β-Oxo Ester Transformation via N-Alkenoxypyridinium Salts as the Activator and H2O as the Nucleophile.

N-Alkenoxypyridinium salts were found to be highly active electrophilic reagents that could be used to activate the C-N bond of amides. Both aromatic amides and aliphatic amides could be transformed into the corresponding β-oxo esters with good yields via the combined use of N-alkenoxypyridinium salts and water. The methodology proceeds under mild reaction conditions and is tolerant of various functional groups in both reaction partners.