Photoredox/Copper Co-catalyzed: Direct C4-H Sulfamidation Of 1-Naphthylamine Derivatives

A simple and efficient protocol for photoredox/copper co-catalyzed regioselective C4-H sulfamidation of 1-naphthylamine derivatives was explored in this thesis.The reaction proceeded smoothly selecting diphenylsulfonimide(HNSI)as sulfamidation reagent,Eosin Y as photocatalyst,PhI(OAc)2 as oxidant,in DCM under air by the household light irradition at room temperature for 6 hours,affording the 1-naphthylamine derivatives C4-site sulfonamide product successfully(Scheme 1).The reaction exhibits high regioselectivity,broad functional group toluerance,acid or base additives-free and mild conditions.Furthermore,the target product can be easily desulfonated to afford the diaminonaphthalene compound.The addition of radical scavenger of 2,6-di-tert-butyl-4-methylphenol(BHT)or 2,2,6,6-tetramethylpiperdin-1-oxyl(TEMPO)successfully suppressed the reaction.Both the adduct of BHT and 1-naphthylamine derivatives as the product and the adduct of BHT and diphenylsulfonimide as the product could be detected by HRMS,respectively.These results suggested that the raction might involve a radical process.Moreover,using D2O as the deuterated reagent,no deuterated 1-naphthylamine derivatives or sulfonated products were obtained under standard conditions,so it is speculated that the C-H bond activation of this reaction is an irreversible process.