Photochemical and photocatalytic reduction of nitrobenzene in the presence of cyclohexene
Photochemical and photocatalytic reduction of nitrobenzene in the presence of cyclohexene
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DOI：
10.1016/s1010-6030(00)00212-4
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发表时间：
2000-05-08
影响因子：
4.3
通讯作者：
Cenini, S
中科院分区：
文献类型：
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作者：
Maldotti, A;Andreotti, L;Cenini, S
在波长大于350 nm的微辐射下，硝基苯和环己烯脱氧混合物的硝基化合物被还原，形成C6H5N(O)=NC6H5（32%）、C6H5N=NC6H5（21%）、C6H5NH2（15%）、C6H5N(H)C6H9（32%）。在TiO2、WO3或cd等粉末分散体存在的情况下进行光化学实验，得到了同样稳定的还原产物。另一方面，这些半导体的光催化作用在相对产物分布中起着重要作用，这取决于所涉及的试剂和中间体在固体表面的竞争性吸附-解吸平衡以及光激发半导体的不同还原能力。环己烯参与硝基苯的光诱导还原，经历氧化，并产生所需的电子和质子。通过ESR自旋俘获研究，获得了该烯烃氧化生成自由基的实验证据。我们首次报道了光诱导环己烯与硝基苯的烯丙基胺化反应，得到了合成感兴趣的C6H5N(H)C6H9的重要组成部分。(C) 2000 Elsevier Science S.A.版权所有
mIrradiation with light of wavelength higher than 350 nm of deaerated mixtures of nitrobenzene and cyclohexene leads to the reduction of the nitro-compound, with the formation of C6H5N(O)=NC6H5 (32%), C6H5N=NC6H5 (21%), C6H5NH2 (15%), C6H5N(H)C6H9 (32%). The same stable reduction products are obtained when the photochemical experiments are carried out in the presence of powder dispersions of TiO2 or WO3 or CdS. On the other hand, the photocatalytic contribution of these semiconductors plays an important role in the relative product distribution, which is observed to depend on both competitive adsorption-desorption equilibria of the involved reagents and intermediates on the solid surface and the different reducing power of the photoexcited semiconductors. Cyclohexene participates in the photoinduced reduction of nitrobenzene, undergoing oxidation, and producing the required electrons and protons. Experimental evidence for the formation of radical species deriving from the oxidation of this alkene is obtained by ESR spin trapping investigation. We report here for the first time, the photoinduced allylic amination of cyclohexene with nitrobenzene to give the important building block of synthetic interest C6H5N(H)C6H9. (C) 2000 Elsevier Science S.A. All rights reserved.