Vanadium(V) oxytrinitrate, VO(NO3)3. A powerful reagent for the nitration of aromatic compounds at room temperature under non-acidic conditions

Regioselective Nitration of Deactivated Mono-Substituted Benzenes Using Acyl Nitrates Over Reusable Acidic Zeolite Catalysts

“…Alternative systems developed recently for nitration of deactivated aromatics include nitric acid in the presence of P 2 O 5 supported on silica gel [18], nitrogen dioxide at low temperatures in the presence of ozone [19], N 2 O 5 in the presence of Fe(acac) 3 as a catalyst [20], urea nitrate and nitrourea [21], nitroguanidine and ethylene glycol dinitrate in concentrated acid [22], vanadium(V) oxytrinitrate in dichloromethane at room temperature [23], and nitric acid in the presence of MCM-41-supported metal bis[(perfluoroalkyl)sulfonyl]imides in dichloroethane [24]. However, such reagents still give mainly the meta-products and moreover, ortho-isomers are often formed in relatively high proportions.…”

KHSO4 as an Efficient Catalytic System for the Regiospecific Nitration of Phenols with Metal Nitrates

“…Furthermore, it is noteworthy that the typical yield of direct nitration never exceeds 60% 26 because of the above mentioned side reactions in most cases, which makes these existing processes uneconomical. On the other hand, the use of metal nitrates like ceric ammonium nitrate, 8 copper nitrate, 32,33 ferric nitrate 7,34 and vanadium nitrate 35 has contributed to this nitration significantly, enhancing the scope of the nitration process however, there are concerns regarding achieving efficient regioselectivity. All these methods also suffer from other drawbacks, for example, some of the nitrates must be prepared from dinitrogen pentoxide, or they must either use the clay supported or absorbed on silica gel prior to their use as nitrating agents.…”

H3+xPMo12−xVxO40 (heteropolyacids)-catalyzed regioselective nitration of phenol to o-nitrophenol in heterogeneous system

“…A variety of nitrating agents have been employed in nitration of phenols but usually these nitration reactions are not selective. Impregnated alumina and silica with N 2 O 4 [4], NaNO 3 in a two phase system (water-ether) in the presence of catalytic amount of La(NO 3 ) 3 [5], an ionic complex of N 2 O 4 with 18-crown-6 [6], ceric ammonium nitrate in the presence of NaHCO 3 [7], metal nitrates [8], nitronium tetrafluoroborate [9], zirconyl nitrate [10], have been used as nitrating agents for phenols.…”