Iodine(Ⅲ)-Mediated Activation Of C(sp~3)-H Bond And Copper(Ⅱ)-Mediated Activation Of C(sp~2)-H Bond

Achieving highly selective activation of carbon-hydrogen bonds without the participation of guiding groups has always been a very challenging topic in the field of organic chemistry.The functionalization of inert C-H bonds is considered to be the holy grail of chemistry and fundamentally changes synthetic chemistry.logical design.However,C-H bonds have higher dissociation energy,usually have higher thermodynamic stability and lower chemical reactivity;in addition,C-H bonds widely exist in organic compounds,and the same compound usually contains multiple C-H bonds.Therefore,the positional selectivity of C-H bond functionalization is a great challenge in traditional chemical synthesis.In recent years,copper-catalyzed/mediated methods of functionalizing C-H bonds to form C-C,C-N,and C-O bonds have attracted great attention.In contrast,copper-catalyzed direct C–S bond formation is still relatively rare.This may be due to catalyst poisoning by sulfur species or sulfur susceptibility to oxidative decomposition or oligomerization.To date,only a few examples of sulfinylation of unactivated arene C–H bonds have been reported.Therefore,the identification of a universally useful and easily manipulated sulfur source is crucial for expanding the practical application of this type of reaction.Elemental sulfur is inexpensive,readily available,and odorless.Therefore,the use of elemental sulfur as a sulfur source in copper-catalyzed unactivated C–H bond reactions is an attractive transition.Based on a review of the representative literature on C-H bond reactions catalyzed by metals and non-metals,this paper carried out studies on non-metal-catalyzed C-H bond reactions and copper-catalyzed functionalized C-H bond formation.The main contents are:1.The efficient functionalization of unactivated hydrocarbons and nitriles by inert C(sp~3)-H bond activation under mild reaction conditions was investigated.Such coupling reactions are achieved in high yields over a broad substrate range.A total of 32 substrates were expanded with a yield of 94%.Oxygen-substituted NHPI derivatives can be converted to alkoxyamines by hydrazinolysis.The alkoxyamines can be further used to synthesize new cephalosporins,azoles,gluconase activators and other organic compounds with antibacterial activity.2.The copper-mediated C-S/N-S bond formation was investigated through the C-H activation reaction using elemental sulfur,and it was found that the addition of TBAI was crucial for this reaction.The method is scalable,exhibits excellent functional group tolerance,and is compatible with heterocyclic substrates,providing an efficient and practical route for the synthesis of benzisothiazolones.The direct conversion of diversified benzisothiazolone products to various sulfur-containing compounds has also been demonstrated.