NiFe2O4 as a magnetically recoverable nanocatalyst for odourless C-S bond formation via the cleavage of C-O bond in the presence of S8 under mild and green conditions

We present green methodologies for one-pot and odourless syntheses of unsymmetric and symmetric diaryl sulfides via CO bond activation using NiFe2O4 magnetic nanoparticles as a reusable heterogeneous nanocatalyst. The synthesis of unsymmetric sulfides is performed using the cross-coupling reaction of phenolic esters such as acetates, triflates and tosylates with arylboronic acid/S-8 or triphenyltin chloride/S-8 as thiolating agents in the presence of base and NiFe2O4 magnetic nanoparticles as a catalyst in poly(ethylene glycol) as solvent at 60-85 degrees C. Also, the synthesis of symmetric diaryl sulfides from phenolic compounds using S-8 as the sulfur source and NiFe2O4 as catalyst in dimethylformamide at 120 degrees C is described. Using these protocols, the syntheses of various unsymmetric and symmetric sulfides become easier than using the available protocols due to the use of a magnetically reusable bimetallic nanocatalyst and avoiding the use of thiols and aryl halides.