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Photoredox catalysis provides a green and sustainable alternative for C−H activation of organic molecules that eludes harsh conditions and use of transition metals. The photocatalytic C−N borylation and C−H arylation mostly depend on the ruthenium and iridium complexes or eosin Y and the use of porphyrin catalysts is still in infancy. A series of novel 21‐thiaporphyrins (A2B2 and A3B type) were synthesized having carbazole/phenothiazine moieties at their meso‐positions and screened as catalysts for C−N borylation and C−H arylation. This paper demonstrates the 21‐thiaporphyrin catalyzed C−N borylation and het‐arylation of anilines under visible light. The method utilizes only 0.1 mol % of 21‐thiaporphyrin catalyst under blue light for the direct C−N borylation and het‐arylation reactions. A variety of substituted anilines were used as source for expensive and unstable aryl diazonium salts in the reactions. The heterobiaryls and aryl boronic esters were obtained in decent yields (up to 88 %). Versatility of the 21‐thiaporphyrin catalyst was tested by thiolation and selenylation of anilines under similar conditions. Mechanistic insight was obtained from DFT studies, suggesting that 21‐thiaporphyrin undergo an oxidative quenching pathway. The photoredox process catalyzed by 21‐thiaporphyrins offers a mild, efficient and metal‐free alternative for the formation of C−C, C−S, and C−Se bonds in aryl compounds; it can also be extended to borylation reaction. [ABSTRACT FROM AUTHOR]

Transition‐metal‐free photoredox catalysis was used for C−N borylation and C−H arylation with 0.1 mol % loading of 21‐thiaporphyrin. Under blue light, a thiaporphyrin catalyst was employed for the synthesis of boronic esters and hetero‐biaryl moieties having furan, thiophene or pyrrole. The methodology was also extended to synthesize diphenyl selenide and diphenyl sulfide derivatives. More information can be found in the Research Article by I. Gupta and co‐workers (DOI: 10.1002/chem.202401623)...By Anu Janaagal; Apoorv Kushwaha; Pranjali Jhaldiyal; T. J. Dhilip Kumar and Iti GuptaReported by Author; Author; Author; Author; Author [Extracted from the article]