159451-63-5Relevant academic research and scientific papers
Well-Defined Amidate-Functionalized N-Heterocyclic Carbene -Supported Rare-Earth Metal Complexes as Catalysts for Efficient Hydroboration of Unactivated Imines and Nitriles
Huang, Zeming,Wang, Shaowu,Zhu, Xiancui,Yuan, Qingbing,Wei, Yun,Zhou, Shuangliu,Mu, Xiaolong
, p. 15069 - 15078 (2018/12/14)
Four amidate-functionalized N-heterocyclic carbene (NHC) rare-earth metal amido complexes [(κ2-N,O-κ1-L)2REN(SiMe3)2] (L = 1-(C6H5CONCH2CH2)-3-(CH3)3C6H2(N(CH)2NC)) [RE = Er (1), Y (2), Dy (3), Gd (4)] were synthesized by one-pot reactions of 2 equiv of (1-(C6H5CONHCH2CH2)-3-(CH3)3C6H2-(N(CH)2NCH))Br (H2LBr) with 5 equiv of KN(SiMe3)3 followed by treatment with 1 equiv of RECl3 in tetrahydrofuran at -40 °C. These complexes were fully characterized, and their catalytic activities toward hydroboration of unactivated imines and nitriles were investigated, and it was found that these complexes displayed excellent activities as well as remarkable functional group compatibility for imine and nitrile substrates such as halo-, alkyl-, hydroxyl-, N,N-dimethylamino-, and nitro- substituents. Among those, the chemoselectivity for this reaction among the common unsaturated functional groups was achieved in the order CO CN > C=N > CO2Et > CC in the current catalytic system, which may facilitate their further application in synthetic chemistry.
Ligand-free CuSO4-catalyzed C-N coupling reaction of aryl halides with alkylamines or N-heterocycles in aqueous solution system
Yang, Hua,Zhang, Xiuli,Si, Jingyu
, p. 5647 - 5648 (2013/07/26)
C-N coupling can be achieved successfully under 80°C in aqueous nBu4NOH using CuSO4 as a catalyst. The study of substrate applicability demonstrated that the C-N coupling reaction of aryl iodides and bromides with alkylamines or N-heterocycles could be completed smoothly in this catalytic system.
Mechanistic investigation of the iridium-catalysed alkylation of amines with alcohols
Fristrup, Peter,Tursky, Matyas,Madsen, Robert
supporting information; experimental part, p. 2569 - 2577 (2012/04/23)
The [Cp*IrCl2]2-catalysed alkylation of amines with alcohols was investigated using a combination of experimental and theoretical methods. A Hammett study involving a series of para-substituted benzyl alcohols resulted in a line with a negative slope. This clearly documents that a positive charge is built up in the transition state, which in combination with the measurement of a significant kinetic isotope effect determines hydride abstraction as being the selectivity-determining step under these conditions. A complementary Hammett study using para-substituted anilines was also carried out. Again, a line with a negative slope was obtained suggesting that nucleophilic attack on the aldehyde is selectivity-determining. A computational investigation of the entire catalytic cycle with full-sized ligands and substrates was performed using density functional theory. The results suggest a catalytic cycle where the intermediate aldehyde stays coordinated to the iridium catalyst and reacts with the amine to give a hemiaminal which is also bound to the catalyst. Dehydration to the imine and reduction to the product amine also takes place without breaking the coordination to the catalyst. The fact that the entire catalytic cycle takes place with all the intermediates bound to the catalyst is important for the further development of this synthetic transformation. The Royal Society of Chemistry 2012.
Ultrathin platinum nanowire catalysts for direct C-N coupling of carbonyls with aromatic nitro compounds under 1 bar of hydrogen
Hu, Lei,Cao, Xueqin,Ge, Danhua,Hong, Haiyan,Guo, Zhiqiang,Chen, Liang,Sun, Xuhui,Tang, Jianxin,Zheng, Junwei,Lu, Jianmei,Gu, Hongwei
experimental part, p. 14283 - 14287 (2012/01/06)
Traditionally important in the pharmaceutical, agrochemical, and synthetic dye industries, C-N coupling has proved useful for the preparation of a number of valuable organic compounds. Here, a new method for the direct one-pot reductive C-N coupling from carbonyl and aromatic nitro compounds is described. Employing ultrathin platinum nanowires as the catalyst and hydrogen as the reducing agent, N-alkylamines were achieved in high yields. Debenzylation products were not detected after prolonged reaction times. Time-dependent analysis, ReactIR spectroscopy and DFT calculations revealed that the C-N coupling proceeded through a different mechanism than traditional "reductive amination." N-Alkylamines were directly obtained by intermolecular dehydration over platinum nanowires under a hydrogen atmosphere, instead of intramolecular water elimination and imine hydrogenation.
Cu-catalyzed carbon-heteroatom coupling reactions under mild conditions promoted by resin-bound organic ionic bases
Huang, Yao-Bing,Yang, Chu-Ting,Yi, Jun,Deng, Xiao-Jian,Fu, Yao,Liu, Lei
experimental part, p. 800 - 810 (2011/04/22)
Resin-bound organic ionic bases (RBOIBs) were developed in which tetraalkyl-ammonium or phosphonium cations are covalently attached to solid resins. The application tests showed that the performance of the tetraalkyl-ammonium-type RBOIBs is slightly better than that of the corresponding Cs salts in Cu-catalyzed C-N cross-couplings, while the tetraalkylphosphonium-type RBOIBs are significantly better than all the inorganic bases. With these newly developed RBOIBs, room-temperature Cu-catalyzed C-Ncoupling with various nonactivated aryl iodides and even aryl bromides can be readily accomplished. Moreover, RBOIBs can be easily recycled and reused for a number of times without much drop of activity. The good performances of RBOIBs are proposed to arise from the relatively weak binding forces between the cationic polymer backbone and basic anions, as opposed to the strong metal-anion interactions in the inorganic bases. Further applications of RBOIBs in Ni-catalyzed Suzuki-type couplings at room temperature, Cu-catalyzed C-N couplings at -30 °C, a Pd-catalyzed Heck reaction at 60 °C, and Cu-catalyzed C-S couplings at room temperature demonstrate that RBOIBs are generally applicable bases with improved performance for many other types of organic transformations.
Novel hydroxyphenylurea dual inhibitor against Acyl-CoA: Cholesterol acyltransferase (ACAT) and low density lipoprotein (LDL) oxidation as antiatherosclerotic agent
Nakao, Kazuya,Kubota, Hitoshi,Yasuhara, Mikiko,Saito, Keiko,Suzuki, Toshikazu,Ohmizu, Hiroshi,Shimizu, Ryo
, p. 853 - 861 (2007/10/03)
Novel hydroxyphenylurea derivatives were synthesized and their inhibitory potency evaluated against acyl-CoA: cholesterol acyltransferase ACAT. Quantitative structure-activity relationship analysis revealed that their ACAT inhibitory activities were controlled by the hydrophobicity of the whole molecule, the substitution pattern of urea moiety, and the existence of carboxylic acid. The derivatives with strong activities inhibited foam cell formations. Moreover, these compounds showed antioxidative effects against low density lipoprotein LDL, owing to their characteristic 3-tert-butyl-2-hydroxy-5-methoxyphenyl substructure. Based on the mechanism of atherosclerosis generation, this hydroxyphenylurea-type dual inhibitor against both ACAT and LDL oxidation is expected to be a promising drug for atherosclerosis. Copyright
Diaryl piperazineacetamides as antimuscarinic agents
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, (2008/06/13)
Diaryl piperzineacetamide compounds useful as antimuscarinic agents for treating a variety of indications such as Parkinson's disease, motion sickness and for the inhibition of gastric acid secretion.
