A fast and efficient method for the preparation of aryl azides using stable aryl diazonium silica sulfates under mild conditions

Heck-type reaction of aryldiazonium silica sulfates

“…Aryldiazonium silica sulfates were prepared according to the previous work [42][43][44]. The products were characterized by comparison with authentic samples and by spectroscopic data (FT-IR, 1 H NMR, 13 C NMR).…”

“…Usually, these compounds are synthesized at around 10°C and handled below 0°C to avoid their decomposition. In previous work [42][43][44] different kinds of aromatic amines were rapidly converted to the corresponding diazonium salts under solvent-free conditions at RT using amine (1 mmol), silica sulfuric acid (0.7 g), and sodium nitrite (2 mmol) which were ground in with a pestle a mortar for a few minutes to obtain an homogeneous mixture. After that, a few drops of water were slowly added and the reaction mixture was ground for 10-15 min until the complete evolution of nitrous acid gas (generated via the reaction of excess nitrite under acidic conditions).…”

“…In following up our research on C-C coupling reactions using ortho-palladated complexes as precatalysts [39][40][41], we have employed various arenediazonium salts synthesized previously [42][43][44] as electrophiles with styrene and methyl acrylate as olefins in Heck-type coupling reactions. The stability of aryldiazonium salts, ArN 2…”

Synthesis of aryl azides from aryl halides promoted by Cu2O/tetraethylammonium prolinate

“…They are generally prepared by diazotization of aromatic amines and subsequent treatment with highly nucleophilic azide ions. 9 However, the direct transformation from aryl halides into aryl azides is still limited. It has been reported that the reaction of aryl halides with sodium azide catalyzed by CuI/L-proline or CuI/DMEDA provided the corresponding aryl azides.…”

“…In continuation of our studies on the synthesis of azides, 9,15,16 herein we introduce an efficient catalytic system based on Cu 2 O/tetraethylammonium prolinate (TEAP), for the reaction of aryl halides with sodium azide in the mixed solvent EtOH/ethylene glycol (EG) (7:3), which provides a variety of aromatic azides (Scheme 1).…”