- Dynamic Ligand Reactivity in a Rhodium Pincer Complex
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Ligand cooperativity provides (transition) metal complexes with new reactivities in substrate activation and catalytic reactions, but usually the ligand acts as an internal (Bronsted) base, while the metal acts as a (Lewis) acid. We describe the synthesis and stepwise activation of a new phosphane-pyridine-amide ligand PNNH2 in combination with RhI. The ligand is susceptible to stepwise proton and hydride loss from the nitrogen arm (imine formation) and deprotonation at the pyridylphosphine arm (dearomatization), giving rise to amine complex 1, amido species 2, imine complex 3 and dearomatized compound 4. Complex 4 bears a dual-mode cooperative PNN′ ligand containing both a (nucleophilic) basic methine fragment and a reactive (electrophilic) imine moiety. The basic ligand arm enables substrate deprotonation while the imine ligand arm enables reversible "storage" of the activated (nucleophilic) form of a sulfonamide substrate at the ligand. In combination with metal-based reactivity, this allows for the mono-alkylation of o-toluenesulfonamide with iodomethane. Compounds 1, 3 and 4 are structurally characterized. We also report the first structurally characterized example of an aminal in the coordination sphere of rhodium, complex 5, [Rh(CO)(PNN′′)], formed by sequential N-H activation of sulfonamide by the dearomatized ligand PNN′ and follow-up nucleophilic attack of anionic sulfonamide onto the imine fragment.
- Tang, Zhou,Otten, Edwin,Reek, Joost N. H.,Van Der Vlugt, Jarl Ivar,De bruin, Bas
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Read Online
- Method for synthesizing N-methyl sulfonamide in water
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The invention discloses a method N - for synthesizing,methylsulfamide in water, by using a transition metal iridium catalyst to catalyze N - methylation reaction. by using a non-toxic and harmless water as a solvent, to avoid using the organic agent; to react only as a byproduct, without an environmental hazard; reaction temperature with respect to the previous strip more mild; and have a wide application prospect; with high selectivity, reaction atomic economy.
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Paragraph 0040-0044
(2020/03/12)
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- N-Methylation of Amines with Methanol in Aqueous Solution Catalyzed by a Water-Soluble Metal-Ligand Bifunctional Dinuclear Iridium Catalyst
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The N-methylation of amines with methanol in aqueous solution was proposed and accomplished by using a water-soluble metal-ligand bifunctional dinuclear iridium catalyst. In the presence of [(Cp*IrCl)2(thbpym)][Cl]2 (1 mol %), a range of desirable products were obtained in high yields under environmentally benign conditions. Notably, this research exhibited the potential of transition metal-catalyzed activation of methanol as a C1 source for the construction of the C-N bond in aqueous solution.
- Han, Xingyou,Li, Feng,Liu, Peng,Meng, Chong,Tung, Nguyen Thanh
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p. 5815 - 5824
(2020/05/26)
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- Transition-Metal-Free One-Step Synthesis of Ynamides
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A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and (Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.
- Zeng, Xianzhu,Tu, Yongliang,Zhang, Zhenming,You, Changming,Wu, Jiao,Ye, Zhiying,Zhao, Junfeng
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p. 4458 - 4466
(2019/03/26)
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- TRIAZOLOPYRIDINE INHIBITORS OF MYELOPEROXIDASE
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The present invention provides compounds of Formula (I): wherein A, Y and R1 are each as defined in the specification, and compositions comprising any of such novel compounds. These compounds are myeloperoxidase (MPO) inhibitors and/or eosinophil peroxidase (EPX) inhibitors, which may be used as medicaments.
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Paragraph 00322
(2017/03/21)
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- N-Methylation of Amines with Methanol Catalyzed by a Cp?Ir Complex Bearing a Functional 2,2′-Bibenzimidazole Ligand
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A new type of Cp?Ir complex bearing a functional 2,2′-bibenzimidazole ligand was designed, synthesized, and found to be a highly effective and general catalyst for the N-methylation of a variety of amines with methanol in the presence of a weak base (0.3 equiv of Cs2CO3).
- Liang, Ran,Li, Shun,Wang, Rongzhou,Lu, Lei,Li, Feng
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supporting information
p. 5790 - 5793
(2017/11/10)
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- UV Light Induced Direct Synthesis of Phenanthrene Derivatives from a Linear 3-Aryl-N-(arylsulfonyl) Propiolamides
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A novel photochemical approach for the synthesis of phenanthrene derivatives from linear 3-aryl-N-(arylsulfonyl) propiolamides via a tandem radical Smiles rearrangement/C-S bonding/Mallory reaction is disclosed. The control experiment results and isolation of the key intermediates give further insight into the reaction mechanism. Gram scale reaction using a flow reactor demonstrated the synthetic potential applications of our protocol.
- Chen, Ming,Yang, Chao,Wang, Yanpei,Li, Dazhi,Xia, Wujiong
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supporting information
p. 2280 - 2283
(2016/06/01)
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- Synthesis of benzofused five-ring sultams via Rh-catalyzed C-H olefination directed by an N -Ac-substituted sulfonamide group
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A Rh-catalyzed N-Ac-sulfonamide group directed C-H olefination-cyclization to afford benzofused five-ring sultam is described with high yield and a wide range of substrate scope. The N-acetyl group is a key for this transformation implying that N-H acidit
- Li, Xueyuan,Dong, Yi,Qu, Fengyu,Liu, Gang
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p. 790 - 798
(2015/03/05)
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- General and efficient method for direct N-monomethylation of aromatic primary amines with methanol
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The direct N-monomethylation of aromatic primary amines, including arylamines, arylsulfonamides and amino-azoles, using methanol as a methylating agent has been accomplished in the presence of a [CpIrCl2]2/NaOH system. From both synthetic and environmental points of view, the reaction is highly attractive because of low catalyst loading, broad substrate scope and excellent selectivities.
- Li, Feng,Xie, Jianjiang,Shan, Haixia,Sun, Chunlou,Chen, Lin
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p. 8645 - 8652
(2015/03/05)
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- In vivo imaging
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A positron emission tomography (PET)-ready library of candidate pharmaceutical agents is provided which can be prepared by a multistep process wherein the final or penultimate step is a reaction using a PET-ready reagent or a plurality of PET-ready reagents. Methods of preparing and using the libraries are also provided.
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- The reversed Kenner linker: A new safety-catch linker for the preparation of N-alkyl sulfonamides
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matrix presented A new strategy for the solid-phase synthesis of sulfonamides is described. The Kenner safety-catch strategy has been modified such that the carboxylic acid component remains attached to the solid support while the sulfonamide portion is released into solution. An initial demonstration of the scope of this strategy is presented, along with an analysis of the cleavage characteristics and extension to more elaborate products via Suzuki reaction and thiazolidinone synthesis.
- Maclean, Derek,Hale, Ron,Chen, Mingying
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p. 2977 - 2980
(2007/10/03)
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