Photochemical and photocatalytic reduction of nitrobenzene in the presence of cyclohexene

Photocatalytic reduction of nitrobenzene over titanium dioxide: by-product identification and possible pathways

“…As can be seen in figure 2, aniline and acetaldehyde and a small amount of acetic acid (not shown in figure 2) were the expected products according to equation (1), however the intermediates of the photoreduction of nitrobenzene (i.e., nitrosobenzene and N-hydroxylaniline) were also clear detected. As reported in other works [8][9][10][11][12] the photoreduction of nitrobenzene is a 6-electron reaction where the main intermediates are nitrosobenzene and N-hydroxylaniline as shown in figure 3. The proposed reaction mechanism (1) shown in figure 3 was built according to the clearly detected intermediates (nitrosobenzene and N-hydroxylaniline) shown in figure 2 and the results published in Refs.…”

“…In an EPR study of the photoinduced reduction of nitroso compounds in TiO 2 , Brezovaé t al. [10] confirmed the formation of only one stable radical, C 6 H 5 N OH, corresponding to the nitrobenzene photoreduction. These authors also found the production of hydroxyalkyl radicals, such as CH(OH)CH 3 in the case of ethanol used as electron donor, formed via the photogenerated TiO 2 valence band holes.…”

“…The proposed reaction mechanism (1) shown in figure 3 was built according to the clearly detected intermediates (nitrosobenzene and N-hydroxylaniline) shown in figure 2 and the results published in Refs. [8][9][10][11][12]. The first step in the reduction of nitrobenzene is thought to be the electron transfer and we speculate that the anion radical NB-N -OOH (dotted box in figure 3) this radical could be the precursor of nitrosobenzene.…”

Visible light mediated homo- and heterocoupling of benzyl alcohols and benzyl amines on polycrystalline cadmium sulfide

“…17 Cenini reported the formation of similar products, such as azo-, azoxy-and aminobenzene by the photocatalytic anaerobic reaction of nitrobenzene and cyclohexene on CdS in addition to the formation of N-(cyclohex-2-enyl)benzeneamine. 18 The formation of benzoines can be avoided using secondary benzyl alcohol, for example α-methylbenzyl alcohol 9 (Scheme 4). Irradiation of the racemate on CdS gave the diastereomeric mixture of the corresponding 1,2-diols 11 (35% mesodiol; 38% dl-diol) and acetophenone 10 (27%).…”

Study on Photocatalytic Organic Reactions Using Photocatalytic Microreactors

“…9 Although the oxidation ability of photocatalysts is often the focus, they also have reducing ability, which could be controlled by depositing noble metals on the surface 5,10 and the reduction reaction of nitrobenzene has been well studied. [11][12][13][14] If inorganic photocatalysts could be utilized effectively for organic syntheses and conversions, it would be beneficial as 'green chemistry' since they are mostly non-toxic and also easily separated after reactions because they are particulate. Furthermore, a wide variety of new photocatalytic materials with the capability of visible-light reaction have been developed in recent years due to strong demand for light harvesting applications such as solar fuels and solar cells.…”