388078-34-0Relevant articles and documents
Utilization of renewable formic acid from lignocellulosic biomass for the selective hydrogenation and/or N-methylation
Zhou, Chao-Zheng,Zhao, Yu-Rou,Tan, Fang-Fang,Guo, Yan-Jun,Li, Yang
, p. 4724 - 4728 (2021/09/06)
Lignocellulosic biomass is one of the most abundant renewable sources in nature. Herein, we have developed the utilization of renewable formic acid from lignocellulosic biomass as a hydrogen source and a carbon source for the selective hydrogenation and further N-methylation of various quinolines and the derivatives, various indoles under mild conditions in high efficiencies. N-methylation of various anilines is also developed. Mechanistic studies indicate that the hydrogenation occurs via a transfer hydrogenation pathway.
B(C6F5)3-Catalyzed C3-Selective C-H Borylation of Indoles: Synthesis, Intermediates, and Reaction Mechanism
Zhang, Sutao,Han, Yuxi,He, Jianghua,Zhang, Yuetao
supporting information, p. 1377 - 1386 (2018/02/10)
Without the addition of any additives and production of any small molecules, C3-borylated indoles and transfer hydrogenated indolines have been simultaneously achieved by a B(C6F5)3-catalyzed disproportionation reaction of a broad range of indoles with catecholborane. This catalyst system exhibits excellent catalytic performance for practical applications, such as easy scale-up under solvent-free conditions and long catalytic lifetime over ten sequential additions of starting materials. A combined mechanistic study, including isolation and characterization of key reaction intermediates, analysis of the disproportionation nature of the reaction, in situ NMR of the reaction, and analysis of detailed experimental data, has led to a possible reaction mechanism which illustrates pathways for the formation of both major products and byproducts. Understanding the reaction mechanism enables us to successfully suppress side reactions by choosing appropriate substrates and adjusting the amount of catecholborane needed. More importantly, with an elevated reaction temperature, we could achieve the convergent disproportionation reaction of indoles, in which indolines were continuously oxidized to indoles for the next disproportionation catalytic cycle. Near quantitative conversions and up to 98% yields of various C3-selective borylated indoles were achieved, without any additives or H2 acceptors.
Catalytic system for efficiently catalyzing indole silanization and proton transfer hydrogenation
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Paragraph 0049; 0050; 0064; 0065; 0066; 0067, (2017/09/01)
The invention discloses a catalytic system for efficiently catalyzing indole silanization and proton transfer hydrogenation, and belongs to the technical field of organic synthesis. According to the catalytic system, indole and silane serve as raw materials, tris(pentafluorophenyl) boron (B (C6F5)3) serves as a catalyst, reaction is performed for 10 minutes at the indoor temperature to simultaneously achieve 3-position selective indole silanization and proton transfer hydrogenation or reaction is performed for 10-1440 minutes at the temperature ranging from 100 DEG C to 140 DEG C to achieve 3-position efficient and specific catalytic indole silanization. The catalytic system has the advantages that the catalytic system is convenient to operate, mild in reaction condition, rapid in reaction, high in conversion rate, less in catalyst consumption and applicable to various solvent systems or body systems without any solvents, raw materials are easily acquired, precious metal is omitted, a catalytic intermediate is high in stability and the like.
B(C6F5)3-Catalyzed (Convergent) Disproportionation Reaction of Indoles
Han, Yuxi,Zhang, Sutao,He, Jianghua,Zhang, Yuetao
supporting information, p. 7399 - 7407 (2017/06/05)
A metal-free B(C6F5)3-catalyzed approach is developed for the disproportionation reaction of a series of indoles with various hydrosilanes, without any additives such as base and production of any small molecule such as dihydrogen. This boron catalyst system also exhibits excellent catalytic performance for practical application, such as catalyst loading as low as 0.01 mol % under solvent-free conditions, and a long-life catalytic performance highlighted by a constant catalytic activity being maintained and excellent yields being achieved for the desired products over 10 sequential additions of starting materials. On the basis of characterization of key intermediates through a series of in situ NMR reactions and detailed experimental data, we proposed a reaction mechanism which illustrated pathways for the formation of different products, including both major products and byproducts. Additional control experiments were conducted to support our proposed mechanism. Understanding the mechanism enables us to successfully suppress side reactions by choosing appropriate substrates and hydrosilanes. More importantly, the use of an elevated reaction temperature for continuous oxidation of the resulting indoline to indole makes the convergent disproportionation reaction an ideal atom-economical process. Near-quantitative conversions and up to 99% yields of C3-silylated indoles were achieved for various indoles with trisubstituted silanes, Ph3SiH (2b) or Ph2MeSiH (2d).
4-Fluoroanilines: Synthesis and decomposition
Zakrzewska,Kolehmainen,Osmialowski,Gawinecki
, p. 1 - 10 (2007/10/03)
Fourteen N- and/or 2-substituted 4-fluoroanilines were prepared (the series includes N-C2-bridged compounds). Some of them were found to be thermally unstable when dissolved in chloroform. Both 19F NMR spectra and comparison of GIAO-DFT calculated and experimental 13C chemical shifts were used to suggest decomposition products of 4-fluoroanilines.
