Synthesis of Substituted 3‐Allyl‐1‐methylindolin‐2‐ones by Palladium‐Catalyzed Cyclization of N‐(2‐Iodophenyl)‐N‐methylbicyclo[1.1.0]butane‐1‐carboxamides

A palladium‐catalyzed bicyclo[1.1.0]butanes reaction is disclosed for the synthesis of 3‐allylindolin‐2‐ones. Bicyclo[1.1.0]butane derivatives as a class of strained electrophiles and a variety of bicyclo[1.1.0]butane derivatives formed in moderate to excellent yields with very good functional group tolerance. This protocol features mild reaction conditions, broad substrate scope and demonstrated to allow access to 3‐allylindolin‐2‐one architectures from bicyclo[1.1.0]butane substrates.