Iodine- mediated intramolecular amination of ketones: the synthesis of 2-acylindoles and 2-acylindolines by tuning N- protecting groups

A general method for constructing both 2-acylindoles and 2-acylindolines via I-2-mediated intramolecular C-N bond formation is presented, and the selective formation of either 2-acylindoles or 2-acylindolines just depends on the nitrogen protecting groups used in the same substrate skeletons.