The Catalytic Amination of Phenols and Olefinic Compounds with Azo Enophiles

The literature concerning amination of electron rich arenes with azodiesters using catalytic amount of Lewis acids as ZnI2, ZnCl2, CF3SO3H or CF3COOH and reports focused on application of diprotected hydrazine derivatives as versatile intermediates in the synthesis of several important compounds are reviewed. The reports concerning reactions of different olefins with diethyl azodicarboxylate (DEAD) and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) carried out as spontaneous ene-additions or reactions catalyzed by Lewis acids as Et2AlCl, Me2AlCl, BF3, Et2BBr, Ti(OPr)4 and SnCl4 are presented. The catalysis by lithium perchlorate of ene reactions as well as the reactions of organotin phenoxides and electron rich arenes with bis(trichloroethyl) azodicarboxylate, (DEAD) and (PTAD) is discussed in this review.