Metal salts with highly electronegative cations as efficient catalysts for the liquid-phase nitration of benzene by NO2 to nitrobenzene

Abstract

Metal salts with highly electronegative cations have been used to effectively catalyze the liquid-phase nitration of benzene by NO 2 to nitrobenzene under solventfree conditions. Several salts including FeCl O, Fe 2 (SO 4 ) 3 , and CuSO 4 were examined and anhydrous FeCl 3 exhibited the best catalytic performance under the optimal reaction conditions. The benzene conversion and selectivity to nitrobenzene were both over 99%. In addition, it was determined that the metal counterion and the presence of water hydrates in the salt affects the catalytic activity. This method is simple and efficient and may have potential industrial application prospects.

Regioselective nitration of toluene to para‐nitrotoluene with NO2 over dealumination Hβ zeolite: Comparison of organic and inorganic acids

“…According to the presented results and our previous works, [ 1,27–30 ] the possible reaction pathway for the nitration of toluene with NO 2 ‐Ac 2 O‐O 2 over Hβ‐Ox is illustrated in Scheme 1. First, by heterolytic ionic disproportionation, dimeric NO 2 provides nitrosyl cation (NO + ) and nitrate ion (NO 3 − ).…”

Solvent-Free, Low-Temperature, Highly Efficient Catalytic Nitration of Toluene with NO2 Promoted by Molecular Oxygen over Immobilized AlCl3–SiO2

“…In general, there is an equilibrium between liquid NO 2 and N 2 O 4 at the low temperature, and the liquid N 2 O 4 is easy to be dissociated to nitrosyl cation (NO + ) and nitrate ion (NO 3 – ) by the heterolytic ionic disproportionation . Although NO + is deemed to be a weak electrophile, it is easy to be oxidized to nitronium (NO 2 + ), which acts as a powerful electrophilic reagent. , Therefore, according to our obtained results and previous work, ,,, the possible catalytic nitration reaction mechanism of toluene with NO 2 promoted by molecular oxygen over immobilized AlCl 3 –SiO 2 catalyst was suggested in Scheme . First, the dimeric NO 2 can be disproportionated to NO + and NO 3 – , and the resulting NO + is easily oxygenated to NO 2 + in the presence of molecular oxygen.…”

A comparative study of the catalytic nitration of toluene over bimetallic Ce‐Mn modified Hβ zeolite

“…According to the experimental results, theoretical results, and previous works, [ 4,11,31–33 ] the possible reaction mechanism for the nitration of toluene under NO 2 ‐Ac 2 O‐O 2 system over Ce/Mn‐Hβ sample is illustrated in Scheme 1. Firstly, the nitrating agent in NO 2 ‐Ac 2 O‐O 2 system is acetyl nitrate (AcONO 2 ).…”