- Synthesis of new monodentate spiro phosphoramidite ligand and its application in Rh-catalyzed asymmetric hydrogenation reactions
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(Chemical Equation Presented) A new spirocyclic diol, 9,9′- spirobixanthene-1,1′-diol, was synthesized in two steps from readily available starting material m-phenoxyanisole. Resolution of the racemic diol was achieved by cocrystallization with N-benzylcinchondimium chloride and N-benzylquininium chloride in acetonitrile. The corresponding spiro monodentate phosphoramidite ligand has been prepared for Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid derivatives and itaconic acid with excellent enantioselectivities (up to >99% ee).
- Wu, Shulin,Zhang, Weicheng,Zhang, Zhaoguo,Zhang, Xumu
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- Syntheses and Catalytic Hydrogenation Performance of Cationic Bis(phosphine) Cobalt(I) Diene and Arene Compounds
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Chloride abstraction from [(R,R)-(iPrDuPhos)Co(μ-Cl)]2 with NaBArF4 (BArF4=B[(3,5-(CF3)2)C6H3]4) in the presence of dienes, such as 1,
- Zhong, Hongyu,Friedfeld, Max R.,Chirik, Paul J.
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- Versatile synthesis of P-chiral (ephedrine) AMPP ligands via their borane complexes. Structural consequences in Rh-catalyzed hydrogenation of methyl α-acetamidocinnamate
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An efficient and versatile synthesis of aminophosphine phosphinite (AMPP) ligands derived from ephedrine, with possible stereogenic P(III)- center(s) is described, using the borane complex methodology. The reaction of oxazaphospholidine borane with an org
- Moulin, Dominique,Darcel, Christophe,Juge, Sylvain
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- Chiral diphosphites derived from D-glucose: new highly modular ligands for the asymmetric catalytic hydrogenation.
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A series of novel diphosphite ligands derived from readily available D-(+)-glucose have been synthesized. These ligands were screened in the Rh-catalyzed hydrogenation of a series of alpha,beta-unsaturated carboxylic acid derivatives. Both excellent enantioselectivities (ee up to >99%) and activities were achieved. The advantage of these ligands is that their modular nature allows an easy systematic variation in the configuration of the stereocenters (C-3, C-5) at the ligand backbone and in the biaryl substituents, so the optimum configuration for maximum enantioselectivity in asymmetric hydrogenation can be determined. Results show that enantiomeric excesses depend strongly on the absolute configuration of C-3 and slightly on the stereocenter carbon C-5, while the sense of the enantiodiscrimination is predominantly controlled by the configuration of the biaryls at the phosphite moieties. Moreover, the presence of bulky substituents at the ortho-positions of the biaryl diphosphite moieties has a positive effect on enantioselectivity.
- Dieguez, Montserrat,Ruiz, Aurora,Claver, Carmen
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- Instant ligand libraries. Parallel synthesis of monodentate phosphoramidites and in situ screening in asymmetric hydrogenation
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Matrix presented. Chiral phosphoramidites have been identified as excellent ligands for various metal-catalyzed enantioselective transformations. Taking advantage of their easy preparation and modular nature, we designed a fully automated protocol for the
- Lefort, Laurent,Boogers, Jeroen A. F.,De Vries, Andre H. M.,De Vries, Johannes G.
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- A very simple, highly stereoselective and modular synthesis of ferrocene-based P-chiral phosphine ligands
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A very simple, highly stereoselective and modular synthesis of ferrocene-based P-chiral phosphine ligands has been developed. On the basis of this new methodology, several new families of ferrocene-based phosphine ligands have been prepared coupling chirality at phosphorus with other, more standard stereogenic features. The introduction of P-chirality into ferrocene-based phosphine ligands enhances the enantioselective discrimination produced by the corresponding Rh catalyst when a matching among the planar chirality, carbon chirality, and the chirality of phosphorus is achieved. Copyright
- Chen, Weiping,Mbafor, William,Roberts, Stanley M.,Whittall, John
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- Mechanistically Guided One Pot Synthesis of Phosphine-Phosphite and Its Implication in Asymmetric Hydrogenation
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Although hybrid bidentate ligands are known to yield highly enantioselective products in asymmetric hydrogenation (AH), synthesis of these ligands is an arduous process. Herein, a one pot, atom-economic synthesis of a hybrid phosphine-phosphite (L1) is reported. After understanding the reactivity difference between an O-nucleophile versus C-nucleophile, one pot synthesis of Senphos (L1) was achieved (72 %). When L1 was treated with [Rh], 31P NMR revealed bidentate coordination to Rh. Senphos, in the presence of rhodium, catalyzes the AH of Methyl-2-acetamido-3-phenylacrylate and discloses an unprecedented turn over frequency of 2289, along with excellent enantio-selectivity (92 %). The generality is demonstrated by hydrogenating an array of alkenes. The AH operates under mild conditions of 1–2 bar H2 pressure, at room temperature. The practical relevance of L1 is demonstrated by scaling-up the reaction to 1 g and by synthesizing DOPA, a drug widely employed for the treatment of Parkinson's disease. Computational insights indicate that the R isomer is preferred by 3.8 kcal/mol over the S isomer.
- Sen, Anirban,Kumar, Rohit,Pandey, Swechchha,Vipin Raj,Kumar, Pawan,Vanka, Kumar,Chikkali, Samir H.
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supporting information
(2022/01/11)
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- Chiral ferrocene-indole diphosphine ligand as well as preparation method and application thereof
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The invention relates to a chiral ferrocene-indole diphosphine ligand as well as a preparation method and application thereof. The specific preparation method comprises the following steps: dissolving an indole compound and a chiral ferrocene phosphine ac
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Paragraph 0065-0066
(2021/05/22)
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- Chiral ferrocene phosphine-indole aminophosphine ligand as well as preparation method and application thereof
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The invention discloses a chiral ferrocene phosphine-indole aminophosphine ligand as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a chiral ferrocene phosphine-indole intermediate in
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Paragraph 0044-0045
(2021/05/22)
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- 2,3-BISPHOSPHINOPYRAZINE DERIVATIVE, METHOD FOR PRODUCING SAME, TRANSITION METAL COMPLEX, ASYMMETRIC CATALYST, AND METHOD FOR PRODUCING ORGANIC BORON COMPOUND
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Provided is a 2,3-bisphosphinopyrazine derivative represented by the following general formula (1), wherein R1, R2, R3, and R4 represent an optionally substituted straight-chain or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted cycloalkyl group, an optionally substituted adamantyl group, or an optionally substituted phenyl group, R5 represents an optionally substituted alkyl group having 1 to 10 carbon atoms or an optionally substituted phenyl group, each R5 may be the same group or a different group, R6 represents a monovalent substituent, n denotes an integer of 0 to
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Paragraph 0262-0264
(2021/02/19)
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- Prolinol as a Chiral Auxiliary in Organophosphorus Chemistry
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Several strategies for the development of the synthesis of P-chiral organophosphorus compounds with (L)-prolinol as a source of chirality have been examined. A reaction of L-prolinol with a set of different alkyl/arylphosphonous acid diamides led in most of the cases to the quantitative formation of the appropriate bicyclic oxazaphospholidines with complete diastereo and enantioselectivity. The latter were reacted with BH3 complex and the formed borane analogues were submitted to structural modifications leading to tertiary phosphine-boranes. Additionally, the effectiveness of oxazaphospholidines as ligands in transition metal asymmetric catalysis has been tested in hydrogenation of dehydroaminoacid esters and imine.
- Kozio?, Anna E.,W?odarczyk, Adam
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p. 1931 - 1941
(2021/04/06)
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- Asymmetric Reduction of Aromatic α-Dehydroamino Acid Esters with Water as Hydrogen Source
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The asymmetric reduction of aromatic α-dehydroamino acid esters with water as the hydrogen source was developed by a Rh/Cu co-catalytic system. The reaction tolerates various functional groups, providing a valuable synthetic tool to access chiral α-amino acid esters readily. Moreover, the present methodology also was applied in the cost-effective and easy to handle preparation of chiral deuterated α-amino esters by using D2O.
- Dai, Yuze,Chen, Jingchao,Wang, Zheting,Wang, Ting,Wang, Lin,Yang, Yong,Qiao, Xingfang,Fan, Baomin
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supporting information
p. 7141 - 7147
(2021/05/29)
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- Ferrocene boron-containing chiral diphosphine ligand as well as preparation method and application thereof
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The invention relates to a ferrocene boron-containing chiral diphosphine ligand and a preparation method and application thereof. The ferrocene boron-containing chiral diphosphine ligand is a compound shown in the formula (I), and the ligand can be comple
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Paragraph 0099-0101
(2021/07/17)
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- Chiral polycyclic tropane compound as well as preparation method and application thereof
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The invention provides a chiral polycyclic tropane compound as well as a preparation method and application thereof. The invention specifically relates to a tropane compound shown as a formula I, or a salt thereof, or a stereoisomer thereof, or a crystal form thereof, and a preparation method and application thereof. The preparation method disclosed by the invention is simple in process, mild in reaction condition and high in yield, and the obtained product has excellent enantioselectivity and diastereoselectivity. Experiments prove that the tropane compound can effectively inhibit various tumor cells, especially lung cancer cells, melanoma cells, breast cancer cells, in-situ pancreatic cancer cells and pancreatic cancer cells, so that the compound has a wide prospect in preparation of drugs for preventing and/or treating tumors.
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- Chiral phosphine-phosphoramidite ester ligand as well as preparation method and application thereof
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The invention provides a method for preparing a phosphine-phosphoramidite ester ligand from a chiral beta-aminophosphine intermediate and an application of the phosphine-phosphoramidite ester ligand in an asymmetric reaction. Chiral N-(2-(phosphoryl)-1-phenethyl) amide is prepared from the chiral beta-aminophosphine intermediate through an asymmetric hydrogenation reaction of (Z)-(alpha-aryl-beta-phosphoryl) alkenyl amide, and then hydrolysis reduction. The preparation method comprises the following steps: dissolving newly-prepared chlorinated phosphite in toluene, adding a solution formed by dissolving the chiral phosphine-amine compound and triethylamine in toluene into an ice-water bath according to a molar ratio of the chiral phosphine-amine compound to the chlorinated phosphite to the triethylamine of 1: (1-2): (3-5), heating the reaction solution to 18-25 DEG C, stirring and reacting for 10-30 hours, filtering, and carrying out column chromatography to remove the solvent, and recrystallizing to obtain the required phosphine-phosphoramidite ligand. According to the present invention, the asymmetric hydrogenation reaction of the catalyst formed by the ligand and the metal precursor on the double bonds such as C = C, C = N, C = O and the like can achieve the enantioselectivity of 99%; the catalyst is high in activity, and TON reaches up to 10000.
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Paragraph 0054-0057; 0081-0086
(2021/05/22)
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- Scorpio-Ligand: Synthesis of Biphenyl-Dihydroazepine Phosphoramidite Ligands for Asymmetric Hydrogenation
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A novel dihydroazepine-bridged BIPHEP phosphoramidite ligand with an amino acid moiety in the backbone was synthesized and evaluated in the Rh-catalyzed asymmetric hydrogenation. The scorpion tail-like amino acid backbone is capable of hydrogen bond forma
- Auras, Stefanie,Trapp, Oliver
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- Asymmetric Full Saturation of Vinylarenes with Cooperative Homogeneous and Heterogeneous Rhodium Catalysis
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Homogeneous and heterogeneous catalyzed reactions can seldom operate synergistically under the same conditions. Here we communicate the use of a single rhodium precursor that acts in both the homogeneous and heterogeneous phases for the asymmetric full saturation of vinylarenes that, to date, constitute an unmet bottleneck in the field. A simple asymmetric hydrogenation of a styrenic olefin, enabled by a ligand accelerated effect, accounted for the facial selectivity in the consecutive arene hydrogenation. Tuning the ratio between the phosphine ligand and the rhodium precursor controlled the formation of homogeneous and heterogeneous catalytic species that operate without interference from each other. The system is flexible in terms of both the chiral ligand and the nature of the external olefin. We anticipate that our findings will promote the development of asymmetric arene hydrogenations.
- Andersson, Pher G.,Massaro, Luca,Peters, Bram B. C.,Wu, Haibo,Yang, Jianping,Zheng, Jia
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supporting information
p. 20377 - 20383
(2021/12/03)
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- Transition Metal-Free N-Arylation of Amino Acid Esters with Diaryliodonium Salts
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A transition metal-free approach for the N-arylation of amino acid derivatives has been developed. Key to this method is the use of unsymmetric diaryliodonium salts with anisyl ligands, which proved important to obtain high chemoselectivity and yields. The scope includes the transfer of both electron deficient, electron rich and sterically hindered aryl groups with a variety of different functional groups. Furthermore, a cyclic diaryliodonium salt was successfully employed in the arylation. The N-arylated products were obtained with retained enantiomeric excess.
- Kervefors, Gabriella,Kersting, Leonard,Olofsson, Berit
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supporting information
p. 5790 - 5795
(2021/03/08)
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- Development of a triazinedione-based dehydrative condensing reagent containing 4-(dimethylamino)pyridine as an acyl transfer catalyst
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A new triazinedione-based reagent, (N,N′-dialkyl)triazinedione-4-(dimethylamino)pyridine (ATD-DMAP) was developed for the operationally simple dehydrative condensation of carboxylic acids. This reagent comprises an ATD core and DMAP as the leaving group, which is liberated into the reaction system to accelerate acyl transfer reactions. Upon adding ATD-DMAP to a mixture of carboxylic acids and alcohols in the presence of an amine base, the corresponding esters were formed rapidly at room temperature. Moreover, dehydrative condensation between carboxylic acids and amines using ATD-DMAP proceeded in high yield.
- Liu, Jie,Fujita, Hikaru,Kitamura, Masanori,Shimada, Daichi,Kunishima, Munetaka
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supporting information
p. 4712 - 4719
(2021/06/11)
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- Diaza-Crown Ether-Bridged Chiral Diphosphoramidite Ligands: Synthesis and Applications in Asymmetric Catalysis
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A small library of diaza-crown ether-bridged chiral diphosphoramidite ligands was prepared. In the rhodium-catalyzed asymmetric hydrogenation and hydroformylation reactions, these ligands exhibited distinct properties in catalytic activity and/or enantioselectivity. Hydrogenated products with opposite absolute configurations could be obtained in high yields with excellent ee values by utilizing (S,S)-L1 and (S,S)-L3, respectively. Meanwhile, the addition of alkali metal cations caused variations in catalytic outcomes, showing the supramolecular tunability of these Rh/diphosphoramidite catalytic systems.
- Luo, Yier,Ouyang, Guanghui,Tang, Yuping,He, Yan-Mei,Fan, Qing-Hua
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p. 8176 - 8184
(2020/07/15)
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- BISPHOSPHINOHEXAFLUOROCYCLOPENTENE DERIVATIVE, MANUFACTURING METHOD THEREOF, TRANSITION METAL COMPLEX, AND ORGANIC COMPOUND MANUFACTURING METHOD BASED ON THE SAME
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PROBLEM TO BE SOLVED: To provide an asymmetric catalyst allowing synthesis of an organic compound having appealing properties absent in existing organic compounds. SOLUTION: The invention provides an asymmetric catalyst comprising a transition metal compl
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Paragraph 0181-0183
(2020/08/29)
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- Metal coordination compound, intermediate, preparation method and applications thereof
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The invention discloses a metal coordination compound, an intermediate, a preparation method and applications thereof. According to the invention, the metal coordination compound represented by a formula I can be used as a catalyst for an asymmetric catalytic hydrogenation reaction to efficiently and catalytically synthesize a series of chiral beta-aryl amides with high optical purity (ee value ofmore than 99%) particularly to asymmetrically and catalytically hydrogenate a tetra-substituted alkenyl amide compound to synthesize a chiral amide with high optical purity (ee value of more than 60%), wherein the ligand bearing capacity (s/c) can reach 100000.
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Paragraph 0371-0377
(2020/05/01)
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- Asymmetric Synthesis and Application of Chiral Spirosilabiindanes
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Reported here is the development of a class of chiral spirosilabiindane scaffolds by Rh-catalyzed asymmetric double hydrosilation, for the first time. Enantiopure SPSiOL (spirosilabiindane diol), a new type of chiral building block for the preparation of various chiral ligands and catalysts, was readily prepared on greater than 10 gram scale using this protocol. The potential of this new spirosilabiindane scaffold in asymmetric catalysis was preliminarily demonstrated by development of the corresponding monodentate phosphoramidite ligands (SPSiPhos), which were used in both a Rh-catalyzed hydrogenation and a Pd-catalyzed intramolecular carboamination.
- Chang, Xin,Chen, Hong-Chao,Li, Chuan-Ying,Ma, Pei-Long,Wang, Peng
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supporting information
p. 8937 - 8940
(2020/04/30)
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- Topology-Based Functionalization of Robust Chiral Zr-Based Metal-Organic Frameworks for Catalytic Enantioselective Hydrogenation
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The design and development of robust and porous supported catalysts with high activity and selectivity is extremely significant but very challenging for eco-friendly synthesis of fine chemicals and pharmaceuticals. We report here the design and synthesis of highly stable chiral Zr(IV)-based MOFs with different topologies to support Ir complexes and demonstrate their network structures-dependent asymmetric catalytic performance. Guided by the modulated synthesis and isoreticular expansion strategy, five chiral Zr-MOFs with a flu or ith topology are constructed from enantiopure 1,1′-biphenol-derived tetracarboxylate linkers and Zr6, Zr9, or Zr12 clusters. The obtained MOFs all show high chemical stability in boiling water, strongly acidic, and weakly basic aqueous solutions. The two flu MOFs featuring the dihydroxyl groups of biphenol in open and large cages, after sequential postsynthetic modification with P(NMe2)3 and [Ir(COD)Cl]2, can be highly efficient and recyclable heterogeneous catalysts for hydrogenation of α-dehydroamino acid esters with up to 98% ee, whereas the three ith MOFs featuring the dihydroxyl groups in small cages cannot be installed with P(NMe2)3 to support the Ir complex. Incorporation of Ir-phosphorus catalysts into Zr-MOFs leads to great enhancement of their chemical stability, durability, and even stereoselectivity. This work therefore not only advances Zr-MOFs as stable supports for labile metal catalysts for heterogeneous asymmetric catalysis but also provides a new insight into how highly active chiral centers can result due to the framework topology.
- Jiang, Hong,Zhang, Wenqiang,Kang, Xing,Cao, Ziping,Chen, Xu,Liu, Yan,Cui, Yong
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supporting information
p. 9642 - 9652
(2020/07/02)
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- P-chirogenic diphosphazanes with axially chiral substituents and their use in rh-catalyzed asymmetric hydrogenation
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A convenient synthesis of enantiopure P-chirogenic diphosphazanes incorporating bulky bisphenol and 1,1′-bi-2-naphtholderived substituents via the functionalization of a readily accessible enantiopure lithium phosphinoamide with chlorophosphoridites was developed. Since the product requires no subsequent deprotection, the protocol provides an easy, convenient synthesis of P-chirogenic ligands on the gram scale. The ligands were applied in the Rh-catalyzed asymmetric hydrogenation of benchmark substrates furnishing enantiomeric excess values up to 96%.
- Moritz, Jan-Ole,Chakrabortty, Soumyadeep,Bernd H. Mu.ller,Spannenberg, Anke,Kamer, Paul C. J.
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p. 14537 - 14544
(2020/12/29)
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- Rapid Synthesis of Chiral 1,2-Bisphosphine Derivatives through Copper(I)-Catalyzed Asymmetric Conjugate Hydrophosphination
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1,2-Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)-catalyzed asymmetric hydrophosphination of α,β-unsaturated phosphine sulfides was developed wi
- Xiao, Jun-Zhao,Yin, Liang,Yue, Wen-Jun,Zhang, Shuai
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supporting information
p. 7057 - 7062
(2020/03/23)
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- P-Stereogenic N-Phosphine-Phosphite Ligands for the Rh-Catalyzed Hydrogenation of Olefins
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We have identified a successful family of simple P-stereogenic N-phosphine-phosphite ligands for the Rh-catalyzed asymmetric hydrogenation of olefins. These catalysts show excellent enantiocontrol for α-dehydroamino acid derivatives and α-enamides (ee's u
- Biosca, Maria,De La Cruz-Sánchez, Pol,Diéguez, Montserrat,Pàmies, Oscar
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p. 4730 - 4739
(2020/05/08)
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- P-Chirogenic Triazole-Based Phosphine: Synthesis, Coordination Chemistry, and Asymmetric Catalysis
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Herein we report the synthesis of a new P-chirogenic triazole-based phosphine according to the ephedrine methodology. Upon reaction with late transition-metal derivatives, RhI and PdII, phosphine-triazole forms complexes with bidenta
- Bayardon, Jér?me,Rousselle, Benjamin,Rousselin, Yoann,Bonnin, Quentin,Malacea-Kabbara, Raluca
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p. 4723 - 4729
(2020/07/24)
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- Phenysilane and Silicon Tetraacetate: Versatile Promotors for Amide Synthesis
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Phenylsilane was reevaluated as a useful coupling reagent for amide synthesis. At room temperature, a wide range of amides and peptides were obtained in good to excellent yields (up to 99 %). For the first time, Weinreb amides synthesis mediated by a hydrosilane were also documented. Comparative experiments with various acetoxysilanes suggested the involvement of a phenyl-triacyloxysilane. From this mechanistic study, silicon tetraacetate was shown as an efficient amine acylating agent.
- Morisset, Eléonore,Chardon, Aurélien,Rouden, Jacques,Blanchet, Jér?me
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supporting information
p. 388 - 392
(2020/01/24)
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- Nickel-Catalyzed Asymmetric Hydrogenation of 2-Amidoacrylates
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Earth-abundant nickel, coordinated with a suitable chiral bisphosphine ligand, was found to be an efficient catalyst for the asymmetric hydrogenation of 2-amidoacrylates, affording the chiral α-amino acid esters in quantitative yields and excellent enantioselectivity (up to 96 % ee). The active catalyst component was studied by NMR and HRMS, which helped us to realize high catalytic efficiency on a gram scale with a low catalyst loading (S/C=2000). The hydrogenated products could be simply converted into chiral α-amino acids, β-amino alcohols, and their bioactive derivatives. Furthermore, the catalytic mechanism was investigated using deuterium-labeling experiments and computational calculations.
- Chen, Jianzhong,Gridnev, Ilya D.,Hu, Yawen,Li, Bowen,Zhang, Wanbin,Zhang, Zhenfeng
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p. 5371 - 5375
(2020/02/15)
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- Phosphite-thioether/selenoether Ligands from Carbohydrates: An Easily Accessible Ligand Library for the Asymmetric Hydrogenation of Functionalized and Unfunctionalized Olefins
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A large family of phosphite-thioether/selenoether ligands has been easily prepared from accessible L-(+)-tartaric acid and D-(+)-mannitol and applied in the M-catalyzed (M=Ir, Rh) asymmetric hydrogenation of a broad number of substrates (46 in total). Its highly modular architecture has been crucial to maximize the catalytic performance. Improving most of the reported approaches, this ligand family presents a broad substrate scope. By selecting the ligand parameters high enantioselectivities (ee's up to 99 %) have therefore been achieved in a broad range of both, functionalized and unfunctionalized substrates. Interestingly, both enantiomers of the hydrogenation products can be usually achieved by changing the ligand parameters.
- Margalef, Jèssica,Borràs, Carlota,Alegre, Sabina,Alberico, Elisabetta,Pàmies, Oscar,Diéguez, Montserrat
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p. 2142 - 2168
(2019/04/13)
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- Asymmetric Synthesis of Functionalized Phenylalanine Derivatives via Rh-Catalyzed Conjugate Addition and Enantioselective Protonation Cascade
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The asymmetric conjugate addition of arylboronic acids to N-phthalimidodehydroalanine 1i catalyzed by Rh(I)/L1a enables the facile preparation of chiral functionalized phenylalanines. The reaction proceeds by a conjugate addition and enantioselective protonation cascade, affording a rhodium enolate that undergoes re-face protonation. The reaction tolerates various arylboronic acids and can be used in the gram-scale synthesis of (S)-phenylalanine hydrochloride, demonstrating the reaction scope and the synthetic feasibility of the process.
- Jian, Jia-Hong,Zeng, Hao-Wei,Kuo, Ting-Shen,Wu, Ping-Yu,Wu, Hsyueh-Liang
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supporting information
p. 9468 - 9472
(2019/11/28)
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- Selective Photoredox Trifluoromethylation of Tryptophan-Containing Peptides
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For application in drug discovery and biomedicine, it is crucial to develop new biocompatible methods to modify polypeptides. Herein, a visible-light-induced photoredox trifluoromethylation of tryptophan-containing peptides is reported. Under a mild, biocompatible, and straightforward condition, this strategy could incorporate the trifluoromethyl group into tryptophan residue with excellent chemo- and site-selectivity. The use of lower photocatalyst loading in 2 mol-% and cheap CF3SO2Na salt represents a great catalytic activity and economic CF3 source. This direct trifluoromethylation strategy allows the ready study of fluorinated peptides exploiting 19F-NMR. Additionally, the development of this protocol enables the study of biochemical systems and potentially modulates the function of biomolecules. Careful mechanistic studies (Stern-Volmer fluorescence quenching, EPR, and radical inhibition/trapping experiments) indicate that the reaction would proceed with a radical–radical cross-coupling procedure.
- Ding, Bo,Weng, Yue,Liu, Yunqing,Song, Chunlan,Yin, Le,Yuan, Jiafan,Ren, Yanrui,Lei, Aiwen,Chiang, Chien-Wei
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p. 7596 - 7605
(2019/12/15)
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- A Bulky Three-Hindered Quadrant Bisphosphine Ligand: Synthesis and Application in Rhodium-Catalyzed Asymmetric Hydrogenation of Functionalized Alkenes
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A bulky three-hindered quadrant bisphosphine ligand, di-1-adamantylphosphino(tert-butylmethylphosphino)methane, named BulkyP*, has been synthesized via a convergent short pathway with chromatography-free procedures. The ligand is a crystalline solid and can be readily handled in air. Its rhodium(I) complex exhibits very high enantioselectivities and catalytic activities in the asymmetric hydrogenation of functionalized alkenes.
- Sawatsugawa, Yuuki,Tamura, Ken,Sano, Natsuhiro,Imamoto, Tsuneo
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supporting information
p. 8874 - 8878
(2019/11/03)
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- Inducing Enantioselectivity in a Dynamic Catalyst by Supramolecular Interlocking
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The design of a new class of fluxional biphenyl bisphosphinite (BIBIPHOS) ligands decorated with amino acid-based diamide interaction sites is reported that undergo spontaneous desymmetrization. Hydrogenation of prochiral alkenes using Rh-BIBIPHOS results
- Scholtes, Jan Felix,Trapp, Oliver
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supporting information
p. 6306 - 6310
(2019/04/03)
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- Enantioselectivity Induced by Stereoselective Interlocking: A Novel Core Motif for Tropos Ligands
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Well-defined supramolecular interactions are a powerful tool to control the stereochemistry of a catalytic reaction. In this paper, we report a novel core motif for fluxional 2,2′-biphenyl ligands carrying (S)-amino acid-derived interaction sites in 5,5′-
- Scholtes, Jan Felix,Trapp, Oliver
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p. 11707 - 11714
(2019/08/16)
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- EBINOL axial chiral compound as well as synthesis method and application thereof
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The invention belongs to the field of axial chiral compounds, and discloses an EBINOL axial chiral compound. The EBINOL axial chiral compound has the following general formula(the formula is shown inthe description), wherein R and R are respectively
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Paragraph 0238; 0246-0249
(2019/08/02)
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- Chiral bisphosphine ligands based on quinoline oligoamide foldamers: application in asymmetric hydrogenation
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A series of chiral bisphosphine ligands were designed and synthesized based on single-handed quinoline oligoamide foldamers. The bisphosphine ligands can coordinate with Rh(cod)2BF4 in a 1 : 1 stoichiometry and the resulted chiral Rh(i) catalysts were applied in the asymmetric hydrogenation of α-dehydroamino acid esters, in which excellent conversions and promising levels of enantioselectivity were achieved.
- Zheng, Lu,Zheng, Dan,Wang, Yanru,Yu, Chengyuan,Zhang, Kun,Jiang, Hua
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supporting information
p. 9573 - 9577
(2019/11/20)
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- “Backdoor Induction” of Chirality: Trans-1,2-cyclohexanediamine as Key Building Block for Asymmetric Hydrogenation Catalysts
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This paper describes the synthesis and characterization of 21 chiral monodentate ligands L, assembled of three building blocks utilizing amide bonds: a metal binding triphenylphosphine, a chiral cyclic diamine and an additional substituent for fine-tuning the steric and/or electronic properties. Cis square-planar metal complexes of RhI and PtII with ML2 stoichiometry have been prepared and characterized by spectroscopic methods (NMR, IR, UV-Vis, CD) and DFT calculations. A key feature of the metal complexes is a prochiral metal coordination sphere and “backdoor induction” of chirality from a distant chiral source via an outer-coordination sphere, well-defined by aromatic stacking and hydrogen-bonding. The rhodium complexes were used as catalysts in asymmetric hydrogenation of α,β-dehydroamino acids with excellent yield and selectivity (up to 97 % ee), strongly supporting the “backdoor induction” hypothesis.
- Glasovac, Zoran,Kirin, Sre?ko I.,Kokan, Zoran,Opa?ak, Sa?a,Peri?, Berislav
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supporting information
p. 2115 - 2128
(2019/01/04)
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- Organophosphorus compound based on [2, 2] paracycloalkane skeleton and intermediate thereof, and preparation method and application thereof
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The invention discloses an organophosphorus compound based on [2, 2] paracycloalkane skeleton and intermediates thereof, a preparation method and an application thereof. The organophosphorus compoundincluding phosphinate ligands, phosphite ligands, phosph
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Paragraph 0044; 0096-0098
(2019/05/08)
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- Electrochemical Hydrogenation with Gaseous Ammonia
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As a carbon-free and sustainable fuel, ammonia serves as high-energy-density hydrogen-storage material. It is important to develop new reactions able to utilize ammonia as a hydrogen source directly. Herein, we report an electrochemical hydrogenation of alkenes, alkynes, and ketones using ammonia as the hydrogen source and carbon electrodes. A variety of heterocycles and functional groups, including for example sulfide, benzyl, benzyl carbamate, and allyl carbamate were well tolerated. Fast stepwise electron transfer and proton transfer processes were proposed to account for the transformation.
- Li, Jin,He, Lingfeng,Liu, Xu,Cheng, Xu,Li, Guigen
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supporting information
p. 1759 - 1763
(2019/01/16)
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- 1,3-Dibromo-5,5-dimethylhydantoin as a Precatalyst for Activation of Carbonyl Functionality
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Activation of carbonyl moiety is one of the most rudimentary approaches in organic synthesis and is crucial for a plethora of industrial-scale condensation reactions. In esterification and aldol condensation, which represent two of the most important reactions, the susceptibility of the carbonyl group to nucleophile attack allows the construction of a variety of useful organic compounds. In this context, there is a constant need for development of and improvement in the methods for addition-elimination reactions via activation of carbonyl functionality. In this paper, an advanced methodology for the direct esterification of carboxylic acids and alcohols, and for aldol condensation of aldehydes using widely available, inexpensive, and metal-free 1,3-dibromo-5,5-dimethylhydantoin under neat reaction conditions is reported. The method is air- and moisture-tolerant, allowing simple synthetic and isolation procedures for both reactions presented in this paper. The reaction pathway for esterification is proposed and a scale-up of certain industrially important derivatives is performed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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supporting information
(2019/08/01)
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- Chiral Cyclohexyl-Fused Spirobiindanes: Practical Synthesis, Ligand Development, and Asymmetric Catalysis
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1,1′-Spirobiindane has been one type of privileged skeleton for chiral ligand design, and 1,1′-spirobiindane-based chiral ligands have demonstrated outstanding performance in various asymmetric catalysis. However, the access to enantiopure spirobiindane is quite tedious, which obstructs its practical application. In the present article, a facile enantioselective synthesis of cyclohexyl-fused chiral spirobiindanes has been accomplished, in high yields and excellent stereoselectivities (up to >99% ee), via a sequence of Ir-catalyzed asymmetric hydrogenation of α,α′-bis(arylidene)ketones and TiCl4 promoted asymmetric spiroannulation of the hydrogenated chiral ketones. The protocol can be performed in one pot and is readily scalable, and has been utilized in a 25 g scale asymmetric synthesis of cyclohexyl-fused spirobiindanediol (1S,2S,2′S)-5, in >99% ee and 67% overall yield for four steps without chromatographic purification. Facile derivations of (1S,2S,2′S)-5 provided straightforward access to chiral monodentate phosphoramidites 6a-c and a tridentate phosphorus-amidopyridine 11, which were evaluated as chiral ligands in several benchmark enantioselective reactions (hydrogenation, hydroacylation, and [2 + 2] reaction) catalyzed by transition metal (Rh, Au, or Ir). Preliminary results from comparative studies showcased the excellent catalytic performances of these ligands, with a competency essentially equal to the corresponding well-established privileged ligands bearing a regular spirobiindane backbone. X-ray crystallography revealed a close resemblance between the structures of the precatalysts 20 and 21 and their analogues, which ultimately help to rationalize the almost identical stereochemical outcomes of reactions catalyzed by metal complexes of spirobiindane-derived ligands with or without a fused cyclohexyl ring on the backbone. This work is expected to stimulate further applications of this type of readily accessible skeletons in development of chiral ligands and functional molecules.
- Zheng, Zhiyao,Cao, Yuxi,Chong, Qinglei,Han, Zhaobin,Ding, Jiaming,Luo, Chenguang,Wang, Zheng,Zhu, Dongsheng,Zhou, Qi-Lin,Ding, Kuiling
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supporting information
p. 10374 - 10381
(2018/08/03)
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- BABIPhos Family of Biaryl Dihydrobenzooxaphosphole Ligands for Asymmetric Hydrogenation
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Novel bidentate phosphine ligands BABIPhos featuring a biaryl bis-dihydrobenzooxaphosphole core are presented. Their synthesis was achieved via Pd-catalyzed reductive homocoupling of dihydrobenzooxaphosphole aryl triflates. An efficient route toward various analogues was also established, giving access to phosphines with different electronic and steric properties. The newly obtained ligands demonstrated high efficiency and selectivity in Rh-catalyzed asymmetric hydrogenation of di- and trisubstituted enamides. This new class of ligands is complementary to previously described bidentate benzooxaphosphole ligands BIBOP.
- Li, Guisheng,Zatolochnaya, Olga V.,Wang, Xiao-Jun,Rodríguez, Sonia,Qu, Bo,Desrosiers, Jean-Nicolas,Mangunuru, Hari P. R.,Biswas, Soumik,Rivalti, Daniel,Karyakarte, Shuklendu D.,Sieber, Joshua D.,Grinberg, Nelu,Wu, Ling,Lee, Heewon,Haddad, Nizar,Fandrick, Daniel R.,Yee, Nathan K.,Song, Jinhua J.,Senanayake, Chris H.
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supporting information
p. 1725 - 1729
(2018/04/14)
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- Structural Investigations on Enantiopure P–OP Ligands: A High-Performing P–OP Ligand for Rhodium-Catalysed Hydrogenations
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A second generation of phosphine–phosphite (P–OP) ligands, incorporating a more sterically bulky phosphite group than previous P–OP ligand designs, gave very efficient catalysts for the Rh-catalysed asymmetric hydrogenation of a diverse array of substrate
- Fernández-Pérez, Héctor,Balakrishna, Bugga,Vidal-Ferran, Anton
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p. 1525 - 1532
(2018/04/20)
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- Cobalt-catalyzed asymmetric hydrogenation of enamides enabled by single-electron reduction
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Identifying catalyst activation modes that exploit one-electron chemistry and overcome associated deactivation pathways will be transformative for developing first-row transition metal catalysts with performance equal or, ideally, superior to precious metals. Here we describe a zinc-activation method compatible with high-throughput reaction discovery that identified scores of cobalt-phosphine combinations for the asymmetric hydrogenation of functionalized alkenes. An optimized catalyst prepared from (R,R)-Ph-BPE (Ph-BPE, 1,2-bis[(2R,5R)-2,5-diphenylphospholano]ethane) and cobalt chloride [CoCl2·6H2O] exhibited high activity and enantioselectivity in protic media and enabled the asymmetric synthesis of the epilepsy medication levetiracetam at 200-gram scale with 0.08 mole % catalyst loading. Stoichiometric studies established that the cobalt (II) catalyst precursor (R,R)-Ph-BPECoCl2 underwent ligand displacement by methanol, and zinc promoted facile one-electron reduction to cobalt (I), which more stably bound the phosphine.
- Friedfeld, Max R.,Zhong, Hongyu,Ruck, Rebecca T.,Shevlin, Michael,Chirik, Paul J.
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p. 888 - 893
(2018/05/29)
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- Synthesis of a new bulky phosphite ligand and its application in the enantioselective hydrogenation
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A new bulky phosphite ligand was synthesized and tested in the asymmetric Rh-catalyzed hydrogenation of a series of substrates, including dimethyl itaconate (up to 95% ee), α- and β-dehydroamino acid derivatives (up to 88% and 76% ee, respectively). In th
- Sokolovskaya, Marina V.,Lyubimov, Sergey E.,Mikhel, Igor S.,Birin, Kirill P.,Davankov, Vadim A.
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supporting information
p. 230 - 233
(2018/03/13)
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- Two Stereoinduction Events in One C?H Activation Step: A Route towards Terphenyl Ligands with Two Atropisomeric Axes
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Herein we disclose the synthesis of original chiral scaffolds—ortho-orientated terphenyls presenting two atropisomeric Ar–Ar axes. These unusual structures were built up by using the C?H activation approach, and remarkably, both chiral axes were controlled with excellent stereoselectivity in a single transformation. During the reaction, not only does atroposelective functionalization of a biaryl precursor occur to establish one stereogenic axis, but an unprecedented atropo-stereoselective C?H arylation also takes place to generate the second stereogenic element. These enantiomerically pure ortho-terphenyls show an original tridimensional structure and thus constitute a unique foundation for building up a library of enantiomerically pure bidentate ligands, such as the new ligands S/N-Biax and diphosphine BiaxPhos.
- Dherbassy, Quentin,Djukic, Jean-Pierre,Wencel-Delord, Joanna,Colobert, Fran?oise
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supporting information
p. 4668 - 4672
(2018/03/21)
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- Modular 1,1′-Ferrocenediyl-cored P-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
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A novel ferrocene-based P-stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β-unsubstituted or -substituted itaconates and α-methylene-γ-oxo-carboxylates. (Figure presented.).
- Poklukar, Ga?per,Stephan, Michel,Mohar, Barbara
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supporting information
p. 2566 - 2570
(2018/05/16)
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- Oxidative functionalization of aliphatic and aromatic amino acid derivatives with H2O2 catalyzed by a nonheme imine based iron complex
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The oxidation of a series of N-acetyl amino acid methyl esters with H2O2 catalyzed by a very simple iminopyridine iron(ii) complex 1 easily obtainable in situ by self-assembly of 2-picolylaldehyde, 2-picolylamine, and Fe(OTf)2 was investigated. Oxidation of protected aliphatic amino acids occurs at the α-C-H bond exclusively (N-AcAlaOMe) or in competition with the side-chain functionalization (N-AcValOMe and N-AcLeuOMe). N-AcProOMe is smoothly and cleanly oxidized with high regioselectivity affording exclusively C-5 oxidation products. Remarkably, complex 1 is also able to catalyze the oxidation of the aromatic N-AcPheOMe. A marked preference for the aromatic ring hydroxylation over Cα-H and benzylic C-H oxidation was observed, leading to the clean formation of tyrosine and its phenolic isomers.
- Ticconi, Barbara,Colcerasa, Arianna,Di Stefano, Stefano,Lanzalunga, Osvaldo,Lapi, Andrea,Mazzonna, Marco,Olivo, Giorgio
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p. 19144 - 19151
(2018/05/31)
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- An Atropos Chiral Biphenyl Bisphosphine Ligand Bearing Only 2,2′-Substituents and Its Application in Rh-Catalyzed Asymmetric Hydrogenation
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An atropos chiral biphenyl bisphosphine ligand bearing only 2,2′-substituents was rationally designed and easily synthesized utilizing a bulky chiral t-butylmethylphosphino block. Computational results showed a large difference in the free energies betwee
- Jia, Jia,Ling, Zheng,Zhang, Zhenfeng,Tamura, Ken,Gridnev, Ilya D.,Imamoto, Tsuneo,Zhang, Wanbin
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p. 738 - 743
(2017/12/26)
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- Method for selective removal of t-butyloxycarboryl from nitrogen
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The invention discloses a method for selective removal of t-butyloxycarboryl from nitrogen. According to the synthesis method, directed at a reaction substrate having t-butyloxycarboryl and another acyl protecting group on a molecular nitrogen atom, in the presence of a selectfluor reagent, reaction is carried out in a solution for selective removal of t-butyloxycarboryl and retention of another acyl protecting group. The synthesis method provided by the invention is novel and efficient, is not reported in literature, and can be widely used in total synthesis and drug intermediate synthesis.
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Paragraph 0024-0025; 0026-0028; 0035-0037
(2018/03/26)
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- Esterification of aryl/alkyl acids catalysed by n-bromosuccinimide under mild reaction conditions
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N-halosuccinimides (NXSs) are well-known to be convenient, easily manipulable and low-priced halogenation reagents in organic synthesis. In the present work, N-bromosuccinimide (NBS) has been promoted as the most efficient and selective catalyst among the NXSs in the reaction of direct esterification of aryl and alkyl carboxylic acids. Comprehensive esterification of substituted benzoic acids, mono-, di- and tri-carboxy alkyl derivatives has been performed under neat reaction conditions. The method is metal-free, air- and moisture-tolerant, allowing for a simple synthetic and isolation procedure as well as the large-scale synthesis of aromatic and alkyl esters with yields up to 100%. Protocol for the recycling of the catalyst has been proposed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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- A versatile biosynthetic approach to amide bond formation
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The development of versatile and sustainable catalytic strategies for amide bond formation is a major objective for the pharmaceutical sector and the wider chemical industry. Herein, we report a biocatalytic approach to amide synthesis which exploits the diversity of Nature's amide bond forming enzymes, N-acyltransferases (NATs) and CoA ligases (CLs). By selecting combinations of NATs and CLs with desired substrate profiles, non-natural biocatalytic pathways can be built in a predictable fashion to allow access to structurally diverse secondary and tertiary amides in high yield using stoichiometric ratios of carboxylic acid and amine coupling partners. Transformations can be performed in vitro using isolated enzymes, or in vivo where reactions rely solely on cofactors generated by the cell. The utility of these whole cell systems is showcased through the preparative scale synthesis of a key intermediate of Losmapimod (GW856553X), a selective p38-mitogen activated protein kinase inhibitor.
- Philpott, Helena K.,Thomas, Pamela J.,Tew, David,Fuerst, Doug E.,Lovelock, Sarah L.
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supporting information
p. 3426 - 3431
(2018/08/07)
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- METHOD FOR SYNTHESISING AMIDES
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The present invention relates to a method for synthesising amides that is of general applicability. The method may be performed in vitro or in vivo. Cell lines for use in the in vivo methods also form aspects of the invention. The method for synthesising a non-natural amide comprises: a. reaction of a carboxylic acid with a naturally occurring CoA ligase or a variant thereof; and b. reaction of the product of step a with an amine in the presence of a naturally occurring acyltransferase or a variant thereof; with the proviso that where the CoA ligase and acyltransferase are both naturally occurring, they are not derived from the same source species and do not act sequentially in a metabolic pathway; and with the proviso that the non-natural product is not N-(E)-p-coumaroyl-3-hydroxyanthranilic acid or N-(E)-p-caffeoyl-3-hydroxyanthranilic acid. Further, a method for producing an active pharmaceutical ingredient by the aforementioned method and host cells for carrying out said methods are envisaged.
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Page/Page column 41-42
(2018/03/06)
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