Iron‐Catalyzed Carbenoid‐Transfer Reactions of Vinyl Sulfoxonium Ylides: An Experimental and Computational Study

A method for the generation of unprecedented vinyl carbenoids from sulfoxonium ylides has been developed and applied in the synthesis of a diverse array of heterocycles such as indolizines, pyrroles, 3‐pyrrolin‐2‐ones, and furans. The reactions proceed by FeBr2 catalysis under mild reaction conditions with a broad substrate scope. A reaction pathway involving iron carbenoids is proposed based on a series of control experiments and DFT calculations. Iron out: A method for vinyl carbenoid transfer using sulfoxonium ylides is reported. In situ generation of a sulfoxonium ylide, an iron carbenoid, and nitrogen ylide, with subsequent (3+2) annulation in a one‐pot process leads to indolizines. This reaction demonstrates the efficiency of the method for vinyl‐carbenoid‐mediated transformations.