Cross-Dehydrogenative Coupling Reaction And Arylation Of Quinoxalin-2(1H)-ones Under Iodide/peroxide System Condition

Iodide/peroxide system was considered as a kind of dominated oxidant and radical initiator for the constrction of various chemical bonds such as C-C,C-X and heteroatoms in radical field,realized the formation of heterocyclic ring and functionalization.Iodide or hypervalent iodine promoted organic reactions had some advantages such as mild condition,environmental friendliness,high atomic efficiency,ease of handling.Quinoxalin-2(1H)-one scaffolds exist in many natural products and medicine molecule,have significant biological activities and pharmaceutical properties such as analgesic activity,antibiotic activity,antitumor and reductase inhibitor,thus,quinoxalin-2(1H)-ones play an important role in biology,medicine and total systhesis of nature products.In this paper,first of all,the types of bonding were studied under iodide/peroxide,then many efforts have been made in the preparation of 3-position functional of quinoxalin-2(1H)-ones with various functional groups,a serious of 3-(2-oxo-2-phenylethylidene)-3,4-dihydroquinoxalin-2(1H)-one and 3-aryl-quinoxalin-2(1H)-ones were prepared.This paper is divided into three parts;The chapter one:The application and development of iodide/peroxide system in organic synthesis were summerized,to realize construction of heterocyclic ring and C-H functionalization.And on the basis of previous reports,the methods of direct C-H bond functionalization at the C3-position of quinoxalin-2(1H)-ones were summarized,including arylation,alkylation,etherification,amination,cyanation,phosphonation and trifluoromethylation.The chapter two:TBAI/TBHP system involved in Cross-Dehydrogenative coupling reaction between quinoxalin-2(1H)-ones and acetophenone.We presented a n-Bu4NI-catalyzed radical oxidative coupling of acetophenone and quinoxalin-2(1H)-ones using TBHP as oxidant to access 3-(2-oxo-2-phenylethylidene)-3,4-dihydroquinoxalin-2(1H)-one.This method provided a noval insight into the synthesis of pharmaceutically active 3-acetyl-quinoxalin-2(1H)-ones scaffold results by one-pot method.The chapter three:I2 promoted to the synthesis of 3-pheny1-quinoxalin-2(1H)-ones.It has been shown that tert-butyl peroxybenzoate(TBPB)is an efficient and highly chemoselective benzoylating reagent.In this area,we first disclosed that TBPB could translate into aryl-radicals,triggering subsequent reactions,introduction of an aryl group by means of I2 catalyst,providing a novel method for the C-H bond activity.A serious 3-phenyl-quinoxalin-2(1H)-ones were prepared.