An efficient synthesis of a variety of [1,2,3]­triazolo-[1,5-a]­quinoxalin-4­(5H)-ones via a [3 + 2] cyclization reaction by photoredox catalysis between quinoxalinones and hypervalent iodine­(III) reagents is reported. A range of quinoxalinones and hypervalent iodine­(III) reagents were tolerated well. This cyclization reaction allows access to structurally diverse [1,2,3]­triazolo-[1,5-a]­quinoxalin-4­(5H)-ones in moderate to good yields.

A photocatalyzed cascade double C−C formation via sp 2 C−H bond activation of diarylamines with hypervalent iodine diazo reagents was developed. A variety of diarylamines and hypervalent iodine(III) reagents were tolerated well, and a range of substituted acridines with yields ranging from moderate to excellent was provided efficiently. The protocol introduces diazo groups onto diarylamines and enables subsequent late-stage assembly point functionalization with the diazonium structure, forming two new C−C bonds in a sequential fashion.

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We report here a convenient method to construct polysubstituted azetidines and 2,4-dioxo-1,3-diazabicyclo[3.2.0] compounds with high stereoselectivities in a one-pot reaction mediated by I2. The tetramethylguanidine (TMG)/I2-mediated formal [2 + 2] cycloaddition reaction of α-amidomalonate 1 with enones 2 affords functionalized azetidine derivatives 4 in moderate to good yields with high diastereoselectivity. When the α-ureidomalonate 5 is used instead of 1, 2,4-dioxo-1,3-diazabicyclo[3.2.0]heptanes 8 and 2,4-dioxo-1,3-diazabicyclo[3.2.0]heptenes 9 can be prepared selectively through the control of solvent and temperature. 2,4-Dioxo-1,3-diazabicyclo[3.2.0]heptanes 8 can further undergo ring-opening reactions with different nucleophilic reagents to afford the corresponding polyfunctionalized azetidine derivatives 13-16 with high steroselectivities.

In this work, a novel electrochemiluminescence (ECL) aptasensor based on resonance energy transfer (RET) effect between Ag3PO4-Cu-MOF (Ⅱ) and silver nanoparticles (Ag NPs) was proposed. The ECL emission spectra of...