Regioselective Functionalization of Enamides at the α‑Carbon via Unsymmetrical 2‑Amidoallyl Cations

A new method to functionalize enamides
via an intermediacy of unsymmetrical
2-amidoallyl cations is reported. Generated under mild Brønsted
acid catalysis, these reactive species were found to undergo addition
with various nucleophiles at the less substituted α-carbon to
produce highly substituted enamides in high yields with complete control
of regioselectivity.