- Manganese-Catalyzed Asymmetric Hydrogenation of Quinolines Enabled by π–π Interaction**
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The non-noble metal-catalyzed asymmetric hydrogenation of N-heteroaromatics, quinolines, is reported. A new chiral pincer manganese catalyst showed outstanding catalytic activity in the asymmetric hydrogenation of quinolines, affording high yields and enantioselectivities (up to 97 % ee). A turnover number of 3840 was reached at a low catalyst loading (S/C=4000), which is competitive with the activity of most effective noble metal catalysts for this reaction. The precise regulation of the enantioselectivity were ensured by a π–π interaction.
- Liu, Chenguang,Wang, Mingyang,Liu, Shihan,Wang, Yujie,Peng, Yong,Lan, Yu,Liu, Qiang
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p. 5108 - 5113
(2021/01/21)
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- Synergistic Chemo/Biocatalytic Synthesis of Alkaloidal Tetrahydroquinolines
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The power of complementary chemocatalytic and biocatalytic transformations is demonstrated in the asymmetric synthesis of 2-substituted tetrahydroquinolines. A series of racemic tetrahydroquinolines were synthesized through a convergent one-pot Rh(I)-catalyzed addition/condensation sequence of alkyl vinyl ketones and aminophenylboronic acids. The resulting tetrahydroquinolines were thereafter shown to be substrates for the flavin-dependent enzyme cyclohexylamine oxidase, and preparative-scale deracemizations have been demonstrated on these high-value targets.
- Cosgrove, Sebastian C.,Hussain, Shahed,Turner, Nicholas J.,Marsden, Stephen P.
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p. 5570 - 5573
(2018/05/25)
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- Solvent-Regulated Asymmetric Hydrogenation of Quinoline Derivatives in Oligo(Ethylene Glycol)s through Host–Guest Interactions
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The asymmetric hydrogenation of quinolines in oligo(ethylene glycol)s (OEGs) and poly(ethylene glycol)s (PEGs) with chiral cationic ruthenium diamine complexes has been investigated. Interestingly, in liquid PEGs or long-chain OEGs, the Ru catalysts lost their reactivity. Upon the addition of a little MeOH, the hydrogenation of quinoline was switched “ON”. Evidence from mass spectrometry and control experiments revealed that encapsulation of the quinolinium salt by PEG or long-chain OEG molecules through supramolecular interactions is possibly the main reason for such a switchable hydrogenation reaction. Moreover, the asymmetric hydrogenation of 2-substituted quinoline derivatives was achieved in triethylene glycol (3-OEG), thereby affording 1,2,3,4-tetrahydroquinolines with excellent reactivities and enantioselectivities (up to 99 % ee). Furthermore, the Ru catalyst could be readily recycled for both pure 3-OEG and biphasic 3-OEG/n-hexane systems without a clear loss of reactivity and enantioselectivity.
- Wang, Tianli,Chen, Ya,Ouyang, Guanghui,He, Yan-Mei,Li, Zhiyan,Fan, Qing-Hua
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p. 2773 - 2777
(2016/10/11)
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- Highly enantioselective synthesis of chiral tetrahydroquinolines and tetrahydroisoquinolines by ruthenium-catalyzed asymmetric hydrogenation in ionic liquid
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Asymmetric hydrogenation reactions of quinolines and 3,4- dihydroisoquinolines using the chiral cationic ruthenium complex Ru(TsDPEN) [TsDPEN=N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine] as catalyst in neat imidazolium ionic liquids have been investigated. The catalytic performance was influenced by the anion of the ionic liquids for both substrate classes. A range of 2-alkyl-substituted 1,2,3,4-tetrahydroquinolines and 1-alkyl-substituted 1,2,3,4-tetrahydroisoquinolines was obtained in high yields with up to >99% ee. Interestingly, the hydrogenation of quinoline derivatives bearing a carbonyl group was selective for the C-N (quinoline) over the C-O (ketone) bonds, while such a unique chemoselectivity was not observed in methanol. Furthermore, the ruthenium catalysts could be easily recycled at least 5 times in the asymmetric hydrogenation of 3,4-dihydroisoquinoline by solvent extraction. To further facilitate the recovery of catalyst and reduce the use of organic solvent, a thin film of ionic liquid containing Ru(TsDPEN) was supported on silica gels. This supported ionic liquid-phase catalyst was effective in the asymmetric hydrogenation of quinoline, and could be recycled at least 6 times by simple filtration. Copyright
- Ding, Zi-Yuan,Wang, Tianli,He, Yan-Mei,Chen, Fei,Zhou, Hai-Feng,Fan, Qing-Hua,Guo, Qingxiang,Chan, Albert S. C.
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supporting information
p. 3727 - 3735
(2014/01/06)
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- Highly enantioselective hydrogenation of quinolines using phosphine-free chiral cationic Ruthenium catalysts: Scope, mechanism, and origin of enantioselectivity
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Asymmetric hydrogenation of quinolines catalyzed by chiral cationic η6-arene-N-tosylethylenediamine-Ru(II) complexes have been investigated. A wide range of quinoline derivatives, including 2-alkylquinolines, 2-arylquinolines, and 2-functionalized and 2,3-disubstituted quinoline derivatives, were efficiently hydrogenated to give 1,2,3,4-tetrahydroquinolines with up to >99% ee and full conversions. This catalytic protocol is applicable to the gram-scale synthesis of some biologically active tetrahydroquinolines, such as (-)-angustureine, and 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline, a key intermediate for the preparation of the antibacterial agent (S)-flumequine. The catalytic pathway of this reaction has been investigated in detail using a combination of stoichiometric reaction, intermediate characterization, and isotope labeling patterns. The evidence obtained from these experiments revealed that quinoline is reduced via an ionic and cascade reaction pathway, including 1,4-hydride addition, isomerization, and 1,2-hydride addition, and hydrogen addition undergoes a stepwise H+/H- transfer process outside the coordination sphere rather than a concerted mechanism. In addition, DFT calculations indicate that the enantioselectivity originates from the CH/π attraction between the η6-arene ligand in the Ru-complex and the fused phenyl ring of dihydroquinoline via a 10-membered ring transition state with the participation of TfO- anion.
- Wang, Tianli,Zhuo, Lian-Gang,Li, Zhiwei,Chen, Fei,Ding, Ziyuan,He, Yanmei,Fan, Qing-Hua,Xiang, Junfeng,Yu, Zhi-Xiang,Chan, Albert S. C.
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supporting information; experimental part
p. 9878 - 9891
(2011/08/10)
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- Bronsted acid differentiated metal catalysis by kinetic discrimination
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A Bronsted acid differentiated metal catalyzed hydrogenation has been developed. A combinatorial variation of chiral triflylamides with achiral metal complexes results in a highly active catalyst for the asymmetric reduction.
- Rueping, Magnus,Koenigs, Rene M.
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supporting information; experimental part
p. 304 - 306
(2011/03/17)
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- Asymmetrie hydrogenation with water/silane as the hydrogen source
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"Chamical Equation presentd" Water as a hydride source : A new pathway to form metal-hydride bonds has been developed through the reaction of easily available metal-silyl compounds with water. This method has been successfully applied to asymmetric hydrogenation of heteroaromatic compounds with up to 93 % ee under mild autoclave-free conditions (see scheme).
- Wang, Da-Wei,Wang, Duo-Sheng,Chen, Qing-An,Zhou, Yong-Gui
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supporting information; experimental part
p. 1133 - 1136
(2010/06/12)
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- Asymmetric hydrogenation of quinolines activated by Br?nsted acids
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Enantioselective hydrogenation of quinolines and quinoxalines catalyzed by iridium/diphosphine complex with catalytic amount of Br?nsted acid as activator was developed. In the presence of piperidine·TfOH as the activator, full conversions and up to 92% ee were obtained.
- Wang, Duo-Sheng,Zhou, Yong-Gui
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supporting information; experimental part
p. 3014 - 3017
(2010/07/10)
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- Inhibiting deactivation of iridium catalysts with bulky substituents on coordination atoms
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Introducing bulky groups on the coordination phosphorus atoms can effectively block the formation of inactive dimer species and improve the activity of the iridium catalysts. Results of ESI-MS analysis gave strong evidence. This strategy was successfully
- Wang, Duo-Sheng,Zhou, Juan,Wang, Da-Wei,Guo, Yin-Long,Zhou, Yong-Gui
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supporting information; experimental part
p. 525 - 528
(2010/09/20)
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- Thieme chemistry journal awardees - Where are they now? Asymmetric br?nsted acid catalyzed transfer hydrogenations
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Asymmetric hydrogenations are of great importance in the synthesis of optically active amines. This account highlights the development of the first metal-free transfer hydrogenation that is both highly enantioselective and inspired by natures dehydrogen?ase. Further focus is given to the extension of this bioinspired process to provide a variety of valuable, biologically active products and natural products under mild reaction conditions. Georg Thieme Verlag Stuttgart - New York.
- Rueping, Magnus,Sugiono, Erli,Schoepke, Fenja R.
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scheme or table
p. 852 - 865
(2010/07/06)
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- Highly enantioselective hydrogenation of quinolines under solvent-free or highly concentrated conditions
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The phosphine-free chiral cationic Ru(OTf)(TsDPEN)(η6- cymene) complex was found to be an efficient catalyst for the enantioselective hydrogenation of quinolines under more environmentally friendly solvent-free or highly concentrated conditions
- Wang, Zhi-Jian,Zhou, Hai-Feng,Wang, Tian-Li,He, Yan-Mei,Fan, Qing-Hua
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supporting information; experimental part
p. 767 - 769
(2010/04/23)
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- The development of double axially chiral phosphoric acids and their catalytic transfer hydrogenation of quinolines
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(Chemical Equation Presented) Building a better scaffold: Low loadings (0.2-1 mol%) of new double axially chiral phosphoric acid catalysts 1 based on bisbinol scaffold were used for asymmetric transfer hydrogenation. 2-Aryl- and 2-alkyl-substituted quinolines gave tetrahydroquinolines in excellent yields and with up to 98% ee and 2,3-disubstituted tetrahydroquinolines were prepared in high diastereo- and enantioselectivities (up to > 20:1 and 92% ee).
- Guo, Qun-Sheng,Du, Da-Ming,Xu, Jiaxi
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p. 759 - 762
(2008/12/20)
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- Synthesis of tunable bisphosphine ligands and their application in asymmetric hydrogenation of quinolines
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(Chemical Equation Presented) A series of tunable axial chiral bisphosphine ligands have been synthesized from (S)-MeO-Biphep. The Ir complex of the MeO-PEG-supported ligand (S)-4k has been successfully applied in asymmetric hydrogenation of quinolines with up to 92% ee. The catalyst system is air-stable and recyclable.
- Wang, Xiao-Bing,Zhou, Yong-Gui
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p. 5640 - 5642
(2008/12/21)
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- Enantioselective hydrogenation of quinolines catalyzed by Ir(BINAP)-cored dendrimers: Dramatic enhancement of catalytic activity
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Figure presented The asymmetric hydrogenation of quinolines catalyzed by chiral dendritic catalysts derived from BINAP gave the corresponding products with high enantioselectivities (up to 93%), excellent catalytic activities (TOF up to 3450 h-1), and productivities (TON up to 43 000). In addition, the third-generation catalyst could be recovered by precipitation and filtration and reused at least six times with similar enantioselectivity.
- Wang, Zhi-Jian,Deng, Guo-Jun,Li, Yong,He, Yan-Mei,Tang, Wei-Jun,Fan, Qing-Hua
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p. 1243 - 1246
(2007/10/03)
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- Iridium-catalyzed asymmetric transfer hydrogenation of quinolines with Hantzsch esters
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The iridium-catalyzed enantioselective transfer hydrogenation of quinolines with Hantzsch esters was developed with up to 88% ee using [Ir(COD)Cl]2/(S)-SegPhos/I2 as a catalyst.
- Wang, Da-Wei,Zeng, Wei,Zhou, Yong-Gui
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p. 1103 - 1107
(2008/02/08)
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- A highly enantioselective Bronsted acid catalyzed cascade reaction: Organocatalytic transfer hydrogenation of quinolines and their application in the synthesis of alkaloids
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(Chemical Equation Presented) A categorical success: A Bronsted acid catalyzed cascade transfer hydrogenation provides direct access to 2-aryl- and 2-alkyl-substituted tetrahydroquinolines with excellent enantioselectivities under mild conditions and usin
- Rueping, Magnus,Antonchick, Andrey P.,Theissmann, Thomas
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p. 3683 - 3686
(2008/02/12)
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- Asymmetric hydrogenation of quinolines catalyzed by iridium with chiral ferrocenyloxazoline derived N,P ligands
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Chiral ferrocenyloxazoline derived N,P ligands are used in the iridium-catalyzed asymmetric hydrogenation of quinolines, and up to 92% ee was obtained. The role of the planar chirality is also studied.
- Lu, Sheng-Mei,Han, Xiu-Wen,Zhou, Yong-Gui
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p. 909 - 912
(2007/10/03)
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- Highly enantioselective iridium-catalyzed hydrogenation of heteroaromatic compounds, quinolines
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The highly enantioselective hydrogenation of quinoline derivatives is developed using [Ir(COD)Cl]2/(R)-MeO-Biphep/I2 system, and this methodology has been applied to the asymmetric synthesis of three naturally occurring alkaloids angustureine, galipinine, and cuspareine. This method provided an efficient access to a variety of optically active tetrahydroquinolines with up to 96% ee. Copyright
- Wang, Wen-Bo,Lu, Sheng-Mei,Yang, Peng-Yu,Han, Xiu-Wen,Zhou, Yong-Gui
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p. 10536 - 10537
(2007/10/03)
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