Spirocyclization Via Visible-light-induced Dearomatization Of Naphthalenes And Pd-Catalyzed Meta-C-H Iodination Of Anilines

With the development of organic synthesis methodology,the synthesis of spirocyclic compounds via visible-light-induced dearomaticization has become the research focus of organic chemistry.An intramolecular spirocyclizative hydroarylation of non-activated naphthalene derivatives via visible-light-induced dearomaticization is described in the first part of this paper.Using a combination of an organic photoredox catalyst Ru（bpy）₃Cl₂ and an amine reducant DIPEA in a green mixed solvent system Me CN and H₂O,this reaction was compatible with a broad range of substrates under mild conditions.This chemical transformation provides an intriguing idea for the synthesis of complex spirocyclic compounds.In recent years,great progress has been made in transition-metal-catalyzed C-H halogenation reaction of arenes,which was deemed as an efficient and green synthetic strategy.Using a budget aryl iodides as the iodinating reagents,carboxyl-assisted remote meta-C-H iodination of aniline substrates via Pd（II）catalysis is described in the second part of this paper.Using a combination of a transition-metal-catalysis Pd（OAc）₂,a pyridyl ligand 2-hydroxy-5-bromopridine,an iodinating reagents 4-iodo-3-nitrotoluene and a silver additive Ag OAc in solvent HFIP,this reaction admirably override ortho-and para-selectivities of the traditional Fride-Crafts reaction.This method may open up a new path for iodination.