Cp 2 Fe Mediated Electrochemical Synthesis of Phosphonylated Spirocyclic Indolines via Dearomatization of Indoles.

A general and robust strategy for the synthesis of phosphonylated spirocyclic indolines has been developed through Cp 2 Fe-catalyzed electrochemical dearomaztizaion of indoles, which has been proven challenging to achieve via chemical oxidants. A range of phosphonylated 3,3-spiroindolines were obtained in moderate to good yields with excellent diastereoselectivities. The synthetic application was further illustrated by its easy scalability and the antitumor activity of the product.