- Nickel-catalyzed enantioselective hydrogenation of β-(acylamino)acrylates: Synthesis of chiral β-amino acid derivatives
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The nickel-catalyzed asymmetric hydrogenation of β-(acylamino)acrylates has been developed, affording chiral β-amino acid derivatives with excellent yields (95-99% yield) and enantioselectivities (97-99% ee). With the Ni-Binapine system, high enantioselectivities (98-99% ee) have also been obtained in the hydrogenation of Z/E isomeric mixtures of β-alkyl and β-aryl β-(acylamino)acrylates. The synthesis of chiral β-amino acid derivatives on a gram scale has also been achieved with 0.2 mol % catalyst loading.
- Li, Xiuxiu,You, Cai,Li, Shuailong,Lv, Hui,Zhang, Xumu
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supporting information
p. 5130 - 5133
(2017/11/06)
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- Carica papaya lipase catalysed resolution of β-amino esters for the highly enantioselective synthesis of (S)-dapoxetine
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An efficient synthesis of the (S)-3-amino-3-phenylpropanoic acid enantiomer has been achieved by Carica papaya lipase (CPL) catalysed enantioselective alcoholysis of the corresponding racemic N-protected 2,2,2-trifluoroethyl esters in an organic solvent. A high enantioselectivity (E > 200) was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. Based on the resolution of a series of amino acids, it was found that the structure of the substrate has a profound effect on the CPL-catalysed resolution. The enantioselectivity and reaction rate were significantly enhanced by switching the conventional methyl ester to an activated trifluoroethyl ester. When considering steric effects, the substituted phenyl and amino groups should not both be large for the CPL-catalysed resolution. The mechanism of the CPL-catalysed enantioselective alcoholoysis of the amino acids is discussed to delineate the substrate requirements for CPL-catalysed resolution. Finally, the reaction was scaled up, and the products were separated and obtained in good yields (≥ 80 %). The (S)-3-amino-3- phenylpropanoic acid obtained was used as a key chiral intermediate in the synthesis of (S)-dapoxetine with very high enantiomeric excess (> 99 %). A carica papaya lipase catalysed resolution of N-protected β-phenylalanine esters has been developed. High enantioselectivity was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. After 50 % conversion, the products were separated and used as key chiral intermediates for the synthesis of (S)-dapoxetine with > 99 % ee. Copyright
- You, Pengyong,Qiu, Jian,Su, Erzheng,Wei, Dongzhi
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p. 557 - 565
(2013/03/13)
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- Highly efficient iridium-catalyzed asymmetric hydrogenation of unprotected β-enamine esters
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A highly efficient and enantioselective hydrogenation of unprotected β-enamine esters catalyzed by Ir-(S,S)-f-Binaphane complex has been developed. This methodology provides straightforward access to free β-amino acids in high yields with excellent enantioselectivities up to 97% ee and high reactivities (TON > 5000).
- Hou, Guohua,Zhang, Xumu,Li, Wei,Ma, Miaofeng,Zhang, Xiaowei
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supporting information; experimental part
p. 12844 - 12846
(2010/11/05)
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- Readily available chiral phosphine-aminophosphine ligands derived from 1-phenylethylamine for Rh-catalyzed enantioselective hydrogenations
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A series of new chiral phosphine-aminophosphine ligands have been prepared via a two- or three-step transformation from commercially available and inexpensive (S)-1-phenylethylamine, and successfully used in the rhodium-catalyzed asymmetric hydrogenation
- Zhou, Xiao-Mao,Huang, Jia-Di,Luo, Li-Bin,Zhang, Cheng-Lu,Zheng, Zhuo,Hu, Xiang-Ping
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experimental part
p. 420 - 424
(2010/07/02)
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- Chiral 1-phenylethylamine-derived phosphine-phosphoramidite ligands for highly enantioselective Rh-catalyzed hydrogenation of β-(acylamino) acrylates: Significant effect of substituents on 3,3′-positions of binaphthyl moiety
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A series of new chiral phosphine-phosphoramidite ligands with a 3,3′-substituted binaphthyl moiety were prepared from 1-phenylethylamine, and successfully applied in the Rh-catalyzed asymmetric hydrogenation of β-(acylamino)acrylates. The research disclosed that the substituents on the 3,3′-positions of binaphthyl moiety significantly influenced the enantioselectivity.
- Zhou, Xiao-Mao,Huang, Jia-Di,Luo, Li-Bin,Zhang, Chen-Lu,Hu, Xiang-Ping,Zheng, Zhuo
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supporting information; experimental part
p. 2320 - 2322
(2010/07/07)
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- Practical P-chiral phosphane ligand for Rh-catalyzed asymmetric hydrogenation
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A highly electron-donating and conformationally rigid P-chiral bis(trialkylphospholane) ligand 2 (DuanPhos) has been prepared in both enantiomeric forms through a concise synthesis. Rh-2 complex has exhibited remarkably high enantio-selectivities (up to >99% ee) and reactivities (up to 10,000 TON) for the hydrogenation of a wide variety of functionalized prochiral alkenes (5 different types), which provides a very practical catalytic system for the preparation of various synthetically useful chiral compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Liu, Duan,Zhang, Xumu
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p. 646 - 649
(2007/10/03)
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- Practical Rh(I)-catalyzed asymmetric hydrogenation of β-(acylamino) acrylates using a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand: Crucial influence of an N-H proton in the ligand
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(Chemical Equation Presented) Excellent enantioselectivities and high turnovers (S/C = 5000) were achieved in the Rh(I)-catalyzed asymmetric hydrogenation of both β-aryl-and β-alkyl-β-(acylamino)acrylates with a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand, and the presence of an N-H proton in the ligand was demonstrated to have a crucial role in the enantioselectivity.
- Hu, Xiang-Ping,Zheng, Zhuo
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p. 419 - 422
(2007/10/03)
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- Rhodium-catalyzed asymmetric hydrogenation of functionalized olefins using monodentate spiro phosphoramidite ligands
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Novel chiral monodentate phosphorus ligands, SIPHOS, were conveniently synthesized from 1,1′-spirobiindane-7,7′-diol. The Rh complexes of SIPHOS can catalyze the hydrogenation of α-dehydroamino esters in mild conditions, providing α-amino acid derivatives
- Fu, Yu,Guo, Xun-Xiang,Zhu, Shou-Fei,Hu, Ai-Guo,Xie, Jian-Hua,Zhou, Qi-Lin
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p. 4648 - 4655
(2007/10/03)
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- Synthesis of monodentate chiral spiro phosphonites and the electronic effect of ligand in asymmetric hydrogenation
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New monodentate chiral phosphonites were synthesized from enantiomerically pure 1,1′-spirobiindane-7,7′-diol. The phosphonites 2 were efficient ligands for the Rh-catalyzed asymmetric hydrogenation of α- and β-dehydroamino acid derivatives, providing the
- Fu, Yu,Hou, Guo-Hua,Xie, Jian-Hua,Xing, Liang,Wang, Li-Xin,Zhou, Qi-Lin
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p. 8157 - 8160
(2007/10/03)
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- Preparation and asymmetric hydrogenation of β-aryl-substituted β-acylaminoacrylates
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The Rh-catalyzed asymmetric hydrogenation of β-aryl-substituted (E)-β-acylaminoacrylates, which were isolated for the first time, with, for example [Rh{(R,R)- (Et-FerroTANE)}(nbd)]+ as catalyst (see picture) proceeds under very mild conditions
- You, Jingsong,Drexler, Hans-Joachim,Zhang, Songlin,Fischer, Christine,Heller, Detlef
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p. 913 - 916
(2007/10/03)
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- A bisphosphepine ligand with stereogenic phosphorus centers for the practical synthesis of β-aryl-β-amino acids by asymmetric hydrogenation
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Excellent enantioselectivities and reactivities were observed in the hydrogenation of a variety of methyl (Z)-β-aryl-β-(acetyl-amino)acrylates in the presence of a rhodium catalyst with the chiral ligand binapine (see scheme). This bisbinaphthophosphepine
- Tang, Wenjun,Wang, Weimin,Chi, Yongxiang,Zhang, Xumu
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p. 3509 - 3511
(2007/10/03)
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- Highly efficient synthesis of chiral β-amino acid derivatives via asymmetric hydrogenation
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(Formula Presented) The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral β-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenatio
- Tang, Wenjun,Zhang, Xumu
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p. 4159 - 4161
(2007/10/03)
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- Highly effective chiral ortho-substituted BINAPO ligands (o-BINAPO): Applications in Ru-catalyzed asymmetric hydrogenations of β-aryl-substituted β-(acylamino)acrylates and β-keto esters
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A novel family of chiral ortho-substituted BINAPO ligands (o-BINAPO) were synthesized from BINOL, and their Ru complexes were highly efficient catalysts for asymmetric hydrogenation of β-aryl-substituted β-(acylamino)acrylates and β-aryl-substituted β-keto esters. The Ru-bisphosphinite catalysts can tolerate an E/Z mixture of β-aryl-substituted β-(acylamino)acrylates. These highly enantioselective hydrogenations provide a useful way to prepare β-aryl-substituted β-amino acids and β-hydroxyl acids. Copyright
- Zhou, Yong-Gui,Tang, Wenjun,Wang, Wen-Bo,Li, Wenge,Zhang, Xumu
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p. 4952 - 4953
(2007/10/03)
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