A convenient CÀH amination of quinoxalin-2-ones has been developed. This transformation provides concise access to 3-aminoquinoxalin-2(1H)-ones with a broad tolerance of functional groups, utilizing TMSN 3 as an amino source under simple and mild conditions. The target 3-aminoquinoxalin-2(1H)-ones are important intermediates for the synthesis of biologically active 3-N-substituted quinoxalin-2-one derivatives.

The modification of quinoxalin-2(1H)-ones via direct C-H bond functionalization has begun to receive widespread attention, due to quinoxalin-2(1H)-one derivatives' various biological activities and pharmaceutical properties. This mini review concentrates on the accomplishments of arylation, trifluoromethylation, alkylation, and alkoxylation of quinoxalin-2(1H)-ones with hypervalent iodine(III) reagents as reaction partners or oxidants. The reaction conditions and mechanisms are compared and discussed in detail.

An efficient and convenient method to synthesize 6-oxyalkylated 1,2,4-triazine-3,5­(2H, 4H)-diones has been developed via visible-light-induced cross-dehydrogenative coupling reaction between 1,2,4-triazine-3,5­(2H, 4H)-diones and ethers with a wide range of functional group tolerance. The present transformation employs the cheap and low-toxic 2-tert-butylanthraquinone as a metal-free photocatalyst and air as a green oxidant at room temperature. Moreover, this reaction can also be driven by sunlight as a clean energy resource. The synthetic utility of this method is further demonstrated by gram-scale reaction and application in the preparation of key intermediates of bioactive molecules.

A facile and efficient method for the synthesis of primary phosphinamides from Ar2P­(O)–H reagents with stable and readily available ammonium carbonate as an ammonia source is disclosed herein for the first time. This ethyl bromoacetate-mediated primary amination proceeds smoothly under mild and simple conditions, without any metal catalyst or oxidant. Moreover, this method is also appropriate for the reaction of Ar2P­(O)–H with a variety of amines, alcohols, and phenols to construct P–N or P–O bonds, with features of handy operation, good functional group tolerance, and broad substrate scope.

Direct sulfonamidation of quinoxalin-2(1H)-one derivatives has been developed using a readily available Cu salt as the catalyst and inexpensive ammonium persulfate as the oxidant in moderate conditions. Owing to the feature of handy operation and good functional group tolerance, this method provides a convenient and efficient access to curative 3-sulfonamidated quinoxalin-2(1H)-one scaffolds.