- A Metal-Free Direct Arene C?H Amination
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The synthesis of aryl amines via the formation of a C?N bond is an essential tool for the preparation of functional materials, active pharmaceutical ingredients and bioactive products. Usually, this chemical connection is only possible by transition metal-catalyzed reactions, photochemistry or electrochemistry. Here, we report a metal-free arene C?H amination using hydroxylamine derivatives under benign conditions. A charge transfer interaction between the aminating reagents TsONHR and the arene substrates enables the chemoselective amination of the arene, even in the presence of various functional groups. Oxygen was crucial for an effective conversion and its accelerating role for the electron transfer step was proven experimentally. In addition, this was rationalized by a theoretical study which indicated the involvement of a dioxygen-bridged complex with a “Sandwich-like” arrangement of the aromatic starting materials and the aminating agents at the dioxygen molecule. (Figure presented.).
- Wang, Tao,Hoffmann, Marvin,Dreuw, Andreas,Hasagi?, Edina,Hu, Chao,Stein, Philipp M.,Witzel, Sina,Shi, Hongwei,Yang, Yangyang,Rudolph, Matthias,Stuck, Fabian,Rominger, Frank,Kerscher, Marion,Comba, Peter,Hashmi, A. Stephen K.
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supporting information
p. 2783 - 2795
(2021/04/05)
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- Selective partial hydrogenation of dinitrobenzenes to nitroanilines catalyzed by Ru/C
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Ru/C was found to be a highly effective catalyst for the selective partial hydrogenation of a range of dinitrobenzenes to their corresponding nitroanilines with excellent selectivity under mild conditions. Furthermore, the effect from other substitute groups of dinitrobenzenes on partial hydrogenation was also explored in this study. Copyright
- Hou, Jie,Ma, Yonghuan,Li, Yuhan,Guo, Fang,Lu, Lianhai
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scheme or table
p. 974 - 975
(2009/04/06)
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- Effect of the electronic structure of the radical anions of 4-substituted 1,2-and 1,3-dinitrobenzenes on the regioselectivity of reduction of the nitro groups
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Theoretical and experimental regularities of the regioselectivity of the reduction of one of the two nitro groups in unsymmetrical dinitrobenzenes were studied. It was found that the regioselectivity of the formation of isomeric nitroanilines depends on the structure of the substrate and the nature of the reducing agent. The reduction regioselectivity model was verified, according to which radical anion protonation is the major reaction direction. Pleiades Publishing, Inc. 2006.
- Orlov,Begunov,Demidova,Rusakov
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- Catalytic reduction of dinitrobenzenes using a noble metal catalyst and iron or iron salts
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There is provided an improved process for the reduction of optionally substituted dinitrobenzenes to the corresponding nitroanilines with high yields which comprises contacting the dinitrobenzene with hydrogen in an acidic medium in the presence of a catalytic amount of a combination of a noble metal hydrogenation catalyst, and iron or an iron salt. Isomer specific reductions may be achieved with those compounds containing suitable directing substituents. The 2-halo-5-nitroanilines which may be produced in this process may be converted via a multi-step synthesis to useful 1-aryl-4-substituted 1,4-dihydro-5H-tetrazol-5-one herbicides.
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- Selective hydrogenation of polynitroaromatic derivatives with noble metal catalysts in the presence of catalytic amounts of iron
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Hydrogen over PtO2, 5%Pd(c), PdCl2, or 5%Rh(al2O3), in the presence of catalytic amounts of iron and under mild reaction conditions, resulted in the selective reduction of a variety of polynitroaromatic compounds in high yields.
- Theodoridis,Manfredi,Krebs
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p. 6141 - 6144
(2007/10/02)
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