A sustainable C-H functionalization of indoles, pyrroles and furans under a blue LED with iodonium ylides.

Pyrrole and indole derivatives are functionalized via a green initiative with the dimethyl malonate derived phenyl iodonium ylide 4a in the presence of a blue LED via C-H functionalization of the respective heterocycles in methanol to generate the desired compounds 5-7 in moderate to good yields. Control experiments provide insight into the probable reaction mechanism. Finally, the strategy is successfully applied in the generation of azepino[4,5-b]indole 12a/b.

Blue Light-Emitting Diode-Mediated In Situ Generation of Pyridinium and Isoquinolinium Ylides from Aryl Diazoesters: Their Application in the Synthesis of Diverse Dihydroindolizine.

Blue light-emitting diode-mediated environmentally sustainable three component reactions among pyridine/isoquinoline 1/2, aryl diazoesters 3, and acrylic ester/3-alkenyl oxindoles 5/6 provide various dihydroindolizines 7 to 9 in excellent yield. The principle of the strategy is photolytic generation of nitrogen ylides from N-heteroarenes and aryl diazoesters and their subsequent [3 + 2] cycloaddition reaction with dipolarophiles. Detailed mechanistic analysis of the transformation through control experiments establishes this strategy as the foundation for the photolytic multicomponent reaction.

Generation of Aryl Radicals from Aryl Hydrazines via Catalytic Iodine in Air: Arylation of Substituted 1,4-Naphthoquinones.

Arylated building blocks or heterocycles are key to myriad applications, including pharmaceutical drug discovery, materials sciences, and many more. Herein, we have reported a mild and efficient strategy for generation of aryl radicals by reacting appropriate aryl hydrazines with catalytic iodine in open air. The aryl radicals were quenched by diversely substituted 1,4-napthoquinones present in the reaction mixture to afford diversely substituted 2,3-napthoquinones in moderate to excellent yield. Control experiments provided insights into the putative reaction mechanism.

Iodine-Catalyzed Aerobic Diazenylation-Amination of Indole Derivatives.

A mild strategy for consecutive diazenylation and amination of indole moieties has been demonstrated. The functionalization occurs at C3 and C2 carbon atoms, respectively, at the indole scaffold in the presence of catalytic iodine and air at 40 °C in the 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) solvent. It is noteworthy that the aromatic amines are generated in situ by the reaction of aryl hydrazine with iodine. In general, bright red products are obtained in moderate to good yield. Control reactions are conducted to establish the reaction mechanism.