Synthesis of azole-fused thiazinethiones using a carbon disulfide surrogate via C-N/C-S tandem coupling and cyclization under reusable magnetic Cu-MOF-74 catalysis.

An operationally advantageous catalytic protocol for the synthesis of benzo[4,5]imidazo- or imidazo[1,2-c][1,3]thiazinethiones, a class of compounds holding significant potential for biological and pharmacological applications, was reported. Utilizing magnetic Cu-MOF-74 as a reusable heterogeneous catalyst, a sequential C-N/C-S coupling and intramolecular cyclization strategy was developed using a carbon disulfide surrogate that avoids direct handling of CS2. The substrate scope was broad, accommodating a variety of electronic and structural variations, including electron-donating and electron-withdrawing substituents, alongside complex cyclic and alkyl-substituted motifs. Furthermore, evaluation against MCF-7 breast carcinoma cells demonstrated that these synthetic compounds exhibited notable anti-cancer activity, with selected derivatives showing potent concentration-dependent growth inhibition.