461-82-5Relevant articles and documents
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 1618 - 1629 (2021/01/25)
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Method for continuous hydrogenation preparation of aromatic amine through nitro-compound
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Paragraph 0046-0047, (2019/06/27)
The invention provides a method for continuous hydrogenation preparation of aromatic amine through a nitro-compound, and belongs to the field of heterogeneous catalysis. The method comprises the stepsthat the nitro-compound serves as a raw material, nano-porous palladium serves as a catalyst and hydrogen serves as a hydrogen source; a static bed liquid phase catalysis hydrogenation process is utilized for synthesizing the nitro-compound into the aromatic amine, and the activity of the catalyst is not lowered after 400-hour continuous running of the catalyst; continuous hydrogenation is carried out under the catalysis condition of the nano-porous palladium catalyst to obtain an aromatic amine product. The method is mild in reaction condition, high in reaction selectivity, compatible in substrate and good in stability, and industrial production is facilitated.
Catalytic Transfer Hydrodebenzylation with Low Palladium Loading
Yakukhnov, Sergey A.,Ananikov, Valentine P.
, p. 4781 - 4789 (2019/09/16)
A highly-efficient catalytic system for hydrodebenzylation reaction is described. The cleavage of O-benzyl and N-benzyl protecting groups was performed using an uncommonly low palladium loading (0.02–0.3 mol%; TON up to 5000) in a relatively short reaction time. The approach was used for a variety of substrates including pharmaceutically important precursors, and gram-scale deprotection reaction was shown. Transfer conditions together with easy-to-make Pd/C catalyst are the key features of this debenzylation scheme. (Figure presented.).