Pd‐Catalyzed Cyclization of o‐Iodoanilines with Acrylates or Acrylic Acids: A Convenient One‐Step Route to 2‐Quinolinones

A convenient and general method for the construction of 2‐quinolinones was developed in this paper. The Pd‐catalyzed cyclization reaction of various o‐iodoanilines with acrylates or acrylic acids proceeded smoothly to produce 2‐quinolinones in 28–>99 % yields. The key to achieve the cyclization reaction is to utilize suitable base, such as potassium pivalate and potassium acetate. Various synthetically useful functional groups, such as halogen atoms, methoxycarbonyl, and nitro groups, remained intact during the reaction. The effects of catalyst and base on this cyclization reaction and kinetic experiments were investigated to understand the aspect of the reaction. An efficient and convenient method is developed for the synthesis of 2‐quinolinones from o‐iodoanilines with acrylates or acrylic acids. The key to achieve the cyclization reaction is to utilize redox‐neutral base. The reaction mechanism involving a Heck coupling intermediate is well investigated.