Synthesis of azoarenes by reductive dimerization of nitroarenes using ammonium bromide and magnesium

Immobilized antimony species on magnetite: a novel and highly efficient magnetically reusable nanocatalyst for direct and gram-scale reductive-coupling of nitroarenes to azoarenes

“…22,23 In contrast to the multistep strategy, the straightforward oxidativecoupling of aromatic amines to azoarenes [24][25][26] and reductivecoupling of nitroarenes to azoxyarenes [27][28][29][30][31][32][33] was also a subject of more interest. In this context, the application of HCOONH 4 / Pb, 34 43 Zn/NaOH, 44 Bi/KOH, 45 Mg/NH 4 Br, 46 Mg/MeOH, 47 Mg/MCl n (MCl n : TiCl 4 , VCl 3 , CrCl 3 , MoOCl 3 , WCl 6 and FeCl 3 ), 48 Pd(acac) 2 /H 2 , 49 InBr 3 /Et 3 SiH, 50 In(OTf) 3 /Et 3 SiH/O 2 , 51 FeCl 2 $4H 2 O/Li/DTBB, 52 electroreduction, 53 Au/meso CeO 2 /CO, 54 Li/THF, 55 Bi/ball mill 56 and Cr 57 has also been documented for direct conversion of nitroarenes to azoarene materials.…”