TMSOTf‐Catalyzed Annulation of Ynamides with Alkynyl Sulfoxides to Construct Substituted Maleimides

A TMSOTf‐catalyzed annulation was developed for the construction of polysubstituted maleimides from ynamides and alkynyl sulfoxides, using oxygen as a green oxidant and ynamides as both carbon and nitrogen sources. This novel protocol proceeds in the presence of TMSOTf without the need for an expensive catalytic system and tolerates a broad substrate scope, providing a variety of maleimides in generally moderate to good yields under mild reaction conditions.