Successive iodine-magnesium or -copper exchange reactions for the selective functionalization of polyhalogenated aromatics

The presence of an electron-withdrawing group or chelating group was found to direct the halogen-copper and halogen-magnesium exchange with various di- or trihalogenated aromatics. Starting with a triiodobenzoate derivative, a range of tetraacylated benzenes could be prepared and used for a short synthesis of benzodiazines.