Indoles and indazoles are common moieties in pharmaceuticals and naturally occurring bioactive compounds. The development of light-driven methods using earth-abundant transition-metal catalysts offers an attractive route for functionalization of such compounds. Herein, we report a visible-light-induced method for the C3- and N-alkylation of indoles and indazoles with styrenes, catalyzed by Co complexes based on the macrocyclic Mabiq ligand (Mabiq = 2–4:6–8-bis­(3,3,4,4-tetra­methyl­dihydro­pyrrolo)-10–15-(2,2′-biquinazolino)-[15]-1,3,5,8,10,14-hexaene-1,3,7,9,11,14-N6). The photochemical behavior of two CoIII catalysts was examined: Co­(Mabiq)­Cl2 and the newly synthesized Co­(MabiqBr)­Cl2, which contains the Br-modified ligand. Both complexes undergo visible-light-induced homolysis that is significant to their activity but exhibit differences in reactivity. The alkylation reactions are regioselective, furnishing the alkylated indole and indazole products in a Markovnikov fashion with excellent yields of up to 96% across a broad range of substrates. Notably, in contrast to dual-transition-metal and photoredox-catalyzed cross-coupling reactions, our studies reveal that the Co complex plays a dual roleas a photosensitizer and catalytically active metal center with the Mabiq ligand offering regiocontrol.

Photoredox catalysts are integral components of artificial photosystems, and have recently emerged as powerful tools for catalysing numerous organic reactions. However, the development of inexpensive and efficient earth-abundant photoredox catalysts...

Amino acids, which are the building blocks of peptides and proteins, are indispensable chemicals needed by the body for optimal metabolism and proper body functioning. Classiied as essential, nonessential and conditionally essential, amino acids play vital roles in the body such as in protein synthesis and as precursors in the production of secondary metabolism molecules. Amino acid oxygenases also play vital metabolic roles such as in prevention of diseases; as a result, amino acids and their oxygenases isolated from various organisms are potent candidates in treatment of diseases which include cancers, inlammations, as well as antibacterial agents.

Anthocyanins extracted from flowers of Delonix regia and Hibiscus sabdariffa were coupled with diazotised aniline. Spectroscopic analysis revealed the resulting product to be 4-phenylazo phenol. This study provides a viable use for anthocyanins as an alternative source of phenol used in the synthesis of this dye.

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