Visible Light Promoted Direct C3-H Functionalization Of Quinoxaline-2(1H)-ones

The moiety of 3-substituted quinxoalin-2(1H)-ones were found in the skeleton of natural isolates and bioactive molecular,and quinoxalinone have been further applied in the field of medicine and materials.The strategy for direct C3-H functionalization of quinoxaline-2(1H)-ones have been further developed.Arylation,alkylation,acylation,cyanation,silylation,alkoxylation,thioetherification,amination and phophonation of quinoxaline-2(1H)-ones were accomplished under metal-,photo-or electrocatalysis in recent years.In this thesis,recent advances in this research area were reviewed in detail and direct C3-H functionalization of quinoxaline-2(1H)-ones have been investigated.The detail works were listed at below:1.Visible-light mediated C-H alkylation of quinoxaline-2(1H)-ones with 4-alkyldihydropyridines was reported.The reaction utilized hypervalent iodine reagent BI-OAc as radical initiator,which reacted with excited state R-DHPs* to boost the generation of alkyl radical.And,a series of 3-alkylquinxalin-2(1H)-ones have been obtained with up to 98% yields at mild and neutral reaction conditions.It worth to mention that,hypervalent iodine reagent BIOAc,as other electron acceptor of R-DHPs* besides Ni-complex,accelerated alkylation of quinoxaline-2(1H)-ones at the metal-/photocatalyst-free conditions.2.On the basis of above reaction strategy,visible-light promoted acylation of quinoxaline-2(1H)-ones was also achieved.BI-OAc promoted generation of acyl radical from the benzothiazolines via single electron oxidation for acylation of quinoxaline-2(1H)-ones with good functional tolerance,wide substrate scope and mild reaction conditions.Therefore,the natural isolates and medicine-active molecular have been introduced into the skeleton of quinoxaline-2(1H)-ones,which further promoted quinoxalinones apply into the pharmaceutics and material field.