- Base-Mediated Amination of Alcohols Using Amidines
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Novel and efficient base-mediated N-alkylation and amidation of amidines with alcohols have been developed, which can be carried out in one-pot reaction conditions, which allows for the synthesis of a wide range of N-alkyl amines and free amides in good to excellent yields with high atom economy. In contrast to borrowing hydrogen/hydrogen autotransfer or oxidative-type N-alkylation reactions, in which alcohols are activated by transition-metal-catalyzed or oxidative aerobic dehydrogenation, the use of amidines provides an effective surrogate of amines. This circumvents the inherent necessity in N-alkylation of an oxidant or a catalyst to be stabilized by ligands.
- Chen, Jianbin,Fang, Yanchen,Jia, Xiaofei,Jiang, Shaohua,Li, Zehua,Liang, Zuyu,Lu, Fenghong,Qi, Shuo,Ren, Chaoyu,Yu, Shuangming,Zhang, Chunyan,Zhang, Guoying,Zhang, Sheng
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p. 7728 - 7738
(2020/07/15)
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- Nickel(II)-NΛNΛO Pincer Type Complex-Catalyzed N-alkylation of Amines with Alcohols via the Hydrogen Autotransfer Reaction
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A highly sustainable catalytic protocol for the coupling of alcohols and amines for selective monoalkylated amines using Ni(II)-NΛNΛO pincer type complexes through the borrowing hydrogen methodology is described. An array of Ni(II) catalysts (1-3) was synthesized and characterized by various spectral and analytical methods. Furthermore, the distorted square planar geometry of the complexes (1 and 2) was substantiated with single crystal X-ray diffraction study. The inexpensive nickel-based catalytic methodology displays a broad substrate scope for the N-alkylation of aromatic and heteroaromatic amines using a diverse range of primary alcohols with excellent yields up to 97%. The present approach is environmentally benign, which liberates water as the sole byproduct. A short synthesis of drug intermediates such as mepyramine and chloropyramine illustrates the utility of the present protocol.
- Balamurugan, Gunasekaran,Ramesh, Rengan,Malecki, Jan Grzegorz
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p. 7125 - 7135
(2020/06/08)
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- Bidentate geometry-constrained iminopyridyl nickel-catalyzed synthesis of amines or imines via borrowing hydrogen or dehydrogenative condensation
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The efficient Ni-catalyzed N-alkylation of various anilines with alcohols via borrowing hydrogen is reported using a bidentate geometry-constrained iminopyridyl nickel complex as the catalyst. Substituted benzylic alcohols and short/long chain aliphatic alcohols could be applied as the alkylation sources to couple with aromatic and heteroaromatic amines to give a diverse set of N-alkylation outcomes in moderate to excellent yields. The nickel catalytic system was also suitable for aliphatic amines, selectively delivering the corresponding imines via an acceptorless dehydrogenative condensation strategy.
- Jiang, Yong,Hu, Miao,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Jin, Liqun
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supporting information
(2020/11/27)
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- Copper-catalyzed direct amination of benzylic hydrocarbons and inactive aliphatic alkanes with arylamines
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A new synthetic method toward direct C-N bond formation through saturated C-H amination of benzylic hydrocarbons and inactive aliphatic alkanes with primary aromatic amines under an inexpensive catalyst/oxidant (Cu/DTBP) system has been developed. Both aminopyridines and anilines could react smoothly with primary and secondary benzylic C-H substrates or cyclohexane to form the corresponding aromatic secondary amines in moderate to good yields. This protocol has the advantages of wide functional group tolerance and use of readily available raw materials.
- Jin, Shengzhou,Lin, Sen,Xie, Bo,Yan, Zhaohua,Yao, Hua,Zhong, Xiaoyang
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supporting information
p. 3263 - 3268
(2020/05/14)
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- Hemilabile N-heterocyclic carbene (NHC)-nitrogen-phosphine mediated Ru (II)-catalyzed N-alkylation of aromatic amine with alcohol efficiently
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Based on the hemilability, a novel N-heterocyclic carbene (NHC)-nitrogen-phosphine ligand (1) was synthesized, and the combination of it with [Ru(COD)Cl2]n showed the high activity and selectivity with a low Ru loading of 0.1% for the N-alkylation of amine with alcohol. Especially, for these substrates with pyridine backbone, even if the catalyst loading was as low as 0.01%, good yields (81–95%) of the desired products were achieved.
- Yu, Xiao-Jun,He, Hai-Yu,Yang, Lei,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
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- Pyridine salt tyrosine kinase inhibitor, preparation method and its use
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The invention relates to pyridinium salty tyrosine kinases inhibitors, and a preparation method and an application thereof in preparation of medicines for treating immune, inflammatory, autoimmune or allergic diseases or transplant rejection diseases and the like. FORMULA as shown in the specification, wherein R is chosen from H, C1-C3 alkyl and C3-C8 cycloalkyl.
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Paragraph 0022; 0023; 0024
(2016/12/01)
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- A mild method for the regioselective bromination of 2-aminopyridines
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An efficient and regioselective bromination of 2-aminopyridines was developed. The environmental friendly bromination occurs under mild and clean conditions using readily available 1-butylpyridinium bromide as the bromine source and hydrogen peroxide as the green oxidant.
- Xu, Tong,Zhou, Wen,Wang, Jing,Li, Xue,Guo, Jun-Wen,Wang, Bin
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p. 5058 - 5061
(2015/01/08)
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- A metal-free tandem demethylenation/C(sp2)-H cycloamination process of N -Benzyl-2-aminopyridines via C-C and C-N bond cleavage
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A mild, metal-free synthesis of pyrido[1,2-a]benzimidazoles starting with N-benzyl-2-aminopyridines, which employs PhI(OPiv)2 as a stoichiometric oxidant, has been developed. The process is initiated by an unusual PhI(OPiv)2-mediated ipso SEAr reaction, followed by solvent-assisted C-C and C-N bond cleavage.
- Liang, Dongdong,He, Yimiao,Liu, Lanying,Zhu, Qiang
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supporting information
p. 3476 - 3479
(2013/07/26)
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- An efficient method for the selective iridium-catalyzed monoalkylation of (hetero)aromatic amines with primary alcohols
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An efficient multi-gram scale synthesis protocol of a variety of P,N ligands is described. The synthesis is achieved in a two-step reaction. First, the amine is deprotonated and subsequently the chlorophosphine is added to yield the corresponding P,N ligand. Deprotonation of the amine is normally achieved with n-BuLi at low temperature, but for the preparation of ligands with a 2,2′-dipyridylamino backbone and phosphines with a high steric demand KH has to be employed in combination with reaction temperatures of 110°C for the salt metathesis step. The reaction of two equivalents of a selected P,N ligand with one equivalent of the iridium complex [IrCl(cod)]2 (cod=1,5-cyclooctadiene) affords P,N ligand-coordinated iridium complexes in quantitative yield. X-Ray single crystal structure analysis of one of these complexes reveals a monomeric five-coordinated structure in the solid state. The iridium complexes were used to form catalysts for the N-alkylation of aromatic amines with alcohols. The catalyst system was optimized by studying 8 different P,N ligands, 9 different solvents and 14 different bases. Systematic variation of the substrate to base and the amine to alcohol ratios as well as the catalyst loading led to optimized catalytic reaction conditions. The substrate scope of the developed catalytic protocol was shown by synthesizing 20 different amines of which 12 could be obtained in isolated yields higher than 90%. A new efficient catalyst system for the selective monoalkylation of primary aromatic and heteroaromatic amines with primary aromatic, heteroaromatic as well as aliphatic alcohols has been established. The reaction proceeds with rather moderate catalyst loadings.
- Blank, Benoit,Madalska, Martyna,Kempe, Rhett
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supporting information; experimental part
p. 749 - 758
(2009/04/10)
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- Imidazopyrimidines, potent inhibitors of p38 MAP kinase
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The MAP kinase p38 is implicated in the release of the pro-inflammatory cytokines TNF-α and IL-1β. Inhibition of cytokine release may be a useful treatment for inflammatory conditions such as rheumatoid arthritis and Crohn's disease. A novel series of imidazopyrimidines have been discovered that potently inhibit p38 and suppress the production of TNF-α in vivo.
- Rupert, Kenneth C.,Henry, James R.,Dodd, John H.,Wadsworth, Scott A.,Cavender, Druie E.,Olini, Gilbert C.,Fahmy, Bohumila,Siekierka, John J.
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p. 347 - 350
(2007/10/03)
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- Substituted 2-aminopyridines as inhibitors of nitric oxide synthase
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Substituted 2-aminopyridine compounds of Formula (I) and pharmaceutically acceptable salts which have been found useful in the treatment of nitric oxide synthase mediated diseases and disorders. STR1
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