- Lewis Base-Boryl Radicals Enabled the Desulfurizative Reduction and Annulation of Thioamides
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A new protocol for radical transformations of thioamides promoted by Lewis base-boryl radicals is reported. The desulfurizative reduction to access organic amines was enabled utilizing 4-dimethylaminopyridine-BH3 as the boryl radical precursor and PhSH as the polarity reversal catalyst. Alternatively, the chain process for unsaturated thioamides was switched to an annulation reaction using N-heterocyclic carbene-BH3 as the boryl radical precursor and sterically bulky Ph3CSH as the catalyst, allowing for the construction of N-heterocyclic and carbocyclic skeletons.
- Yu, You-Jie,Zhang, Feng-Lian,Cheng, Jie,Hei, Jing-Hao,Deng, Wei-Ting,Wang, Yi-Feng
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- Method for reducing thioamide compound
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The invention provides a method for reducing a thioamide compound. The method comprises: at 80 DEG C and under nitrogen protection, taking thioamide as a substrate, adding ditert-butoxyazide (TBHN) and 4-dimethylamino pyridine borane complex (DMAP-BH3) as radical initiators, adding a catalytic amount of thiophenol, and performing stirring in acetonitrile for a proper time to obtain corresponding amine. The same conversion can be achieved by taking triethylborane/oxygen as an initiator at 25 DEG C. The reaction is non-toxic, and is mild in reaction condition, convenient to operate, good in function group tolerance, short in reaction time, and high in efficiency.
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Paragraph 0027; 0032-0034
(2017/10/07)
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- Development of Quinoline-2,4(1H,3H)-diones as Potent and Selective Ligands of the Cannabinoid Type 2 Receptor
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The cannabinoid type 2 receptors (CB2Rs) play crucial roles in inflammatory diseases. There has been considerable interest in developing potent and selective ligands for CB2R. In this study, quinoline-2,4(1H,3H)-dione analogs have been designed, synthesized, and evaluated for their potencies and binding properties toward the cannabinoid type 1 receptor (CB1R) and CB2R. C5- or C8-substituted quinoline-2,4(1H,3H)-diones demonstrate CB2R agonist activity, while the C6- or C7-substituted analogs are antagonists of CB2R. In addition, oral administration of 21 dose-dependently alleviates the clinical symptoms of experimental autoimmune encephalomyelitis in a mouse model of multiple sclerosis and protects the central nervous system from immune damage. Furthermore, the interaction modes predicted by docking simulations and the 3D-QSAR model generated with CoMFA may offer guidance for further design and modification of CB2R modulators.
- Han, Shuang,Zhang, Fei-Fei,Qian, Hai-Yan,Chen, Li-Li,Pu, Jian-Bin,Xie, Xin,Chen, Jian-Zhong
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p. 5751 - 5769
(2015/08/24)
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- Mild and selective hydrogenation of nitro compounds using palladium nanoparticles supported on amino-functionalized mesocellular foam
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We present the utilization of a heterogeneous catalyst comprised of Pd nanoparticles supported on aminopropyl-functionalized siliceous mesocellular foam (Pd0-AmP-MCF) for the selective hydrogenation of aromatic, aliphatic, and heterocyclic nitro compounds to the corresponding amines. In general, the catalytic protocol exclusively affords the desired amine products in excellent yields within short reaction times with the reactions performed at room temperature under ambient pressure of H2. Moreover, the reported Pd nanocatalyst displayed excellent structural integrity for this transformation as it could be recycled multiple times without any observable loss of activity or leaching of metal. In addition, the Pd nanocatalyst could be easily integrated into a continuous-flow device and used for the hydrogenation of 4-nitroanisole on a 2.5 g scale, where the product p-anisidine was obtained in 95% yield within 2 h with a Pd content of less than 1 ppm.
- Verho, Oscar,Gustafson, Karl P. J.,Nagendiran, Anuja,Tai, Cheuk-Wai,B?ckvall, Jan-E.
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p. 3153 - 3159
(2015/02/03)
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- Selective N-alkylation of primary amines with R-NH2·HBr and alkyl bromides using a competitive deprotonation/protonation strategy
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Monoalkylation of primary amines using amine hydrobromides and alkyl bromides has been carried out. Under controlled reaction conditions the reactant primary amine was selectively deprotonated and made available for reaction, while the newly generated secondary amine remained protonated, and did not participate in alkylation further. Reaction was carried out under mild reaction conditions and was applicable to a wide range of primary amines and alkyl bromides.
- Bhattacharyya, Shubhankar,Pathak, Uma,Mathur, Sweta,Vishnoi, Subodh,Jain, Rajeev
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p. 18229 - 18233
(2014/05/20)
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- One-pot reductive mono-n-alkylation of aromatic nitro compounds using nitriles as alkylating reagents
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A one-pot, simple, selective, and efficient protocol for the synthesis of aromatic secondary amines from various nitro arenes and nitriles in the presence of 10% Pd/C catalyst under H2 at atmospheric pressure and ambient temperature in tetrahydrofuran is illustrated. The scope and limitations of this method have been examined.
- Neogi, Subhasish,Naskar, Dinabandhu
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experimental part
p. 1901 - 1915
(2011/07/08)
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- C-N bond formation catalysed by CuI Bonded to polyaniline nanofiber
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Polyaniline nanofiber as a macroligand for the supported cuprous iodide catalyst (CuI-PANInf) has been developed for the coupling of aryl halides (including aryl chlorides) with aliphatic, aromatic, and N(H)-heterocyclic amines under ambient conditions (80 °C for aryl chlorides) has been developed. This simple and efficient method for coupling reactions is highly versatile, convenient, and also the catalyst can be used for several cycles with good-to-excellent yields.
- Arundhathi, Racha,Kumar, Desitti Chaitanya,Sreedhar, Bojja
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supporting information; scheme or table
p. 3621 - 3630
(2010/08/20)
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- PALLADIUM CATALYSTS
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The invention relates to a particulate substance comprising a particulate porous support coupled to a palladium species. The palladium species may comprise palladium nanoclusters. The particulate substance may be used as a catalyst for conducting a carbon-carbon coupling reaction or a reduction.
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Page/Page column 16; 19
(2010/05/13)
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- Highly selective N-Alkylation of amines promoted on silica: An efficient and recyclable surface
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N-Alkylation of amines suffers from competing over alkylations. At the same time, use of strong base and other harsh conditions greatly limits providing a practical, generalized and selective procedure. Activated silica gel has been found to promote N-alkylations of amines. Here, we studied N-alkylation of amines with various types of alkyl halides, which finally constitute practical, highly selective and eco-friendly conditions for mono- or bis-alkylated amines at ambient temperature with recyclability of silica.
- Basu, Basudeb,Paul, Susmita,Nanda, Ashis K.
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experimental part
p. 1115 - 1120
(2010/05/02)
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- Palladium nanoclusters supported on propylurea-modified siliceous mesocellular foam for coupling and hydrogenation reactions
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This paper describes the synthesis, characterization and applications of palladium (Pd) nanoparticles supported on siliceous mesocellular foam (MCF). Pd nanoparticles of 2-3 nm and 4-6 nm were used in reactions involving molecular hydrogen (such as hydrogenation of double bonds and reductive amination), transfer hydrogenation of ketones and epoxides, and coupling reactions (such as Heck and Suzuki reactions). They successfully catalyzed all these reactions with excellent yield and selectivity. This heterogeneous catalyst was easily recovered by filtration, and recycled several times without any significant loss in activity and selectivity. The palladium leaching in the reactions was determined to be much less than the FDA-approved limit of 5 ppm. Furthermore, the catalyst can be stored and handled under normal atmospheric conditions. This immobilized catalyst allows for ease of recovery/reuse and minimization of waste generation, which are of great interest in the development of green chemical processes.
- Erathodiyil, Nandanan,Ooi, Samuel,Seayad, Abdul M.,Han, Yu,Lee, Su Seong,Ying, Jackie Y.
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experimental part
p. 3118 - 3125
(2009/04/08)
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- CuBr/rac-BINOL-catalyzed N-arylations of aliphatic amines at room temperature
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We have developed an efficient and readily available catalyst system CuBr/racemic BINOL ( 1,1′-binaphthyl-2,2′-diol) that catalyzes N-arylation of aliphatic amines at room temperature, and this inexpensive catalyst system is of high selectivity and tolerance toward various functional groups in the substrates.
- Jiang, Deshou,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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p. 672 - 674
(2007/10/03)
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