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Artículos de revistas sobre el tema "N-N axially chiral molecules"

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Autor: Grafiati
Publicado: 6 de septiembre de 2023

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1

Fukasawa, Sota, Tatsuya Toyoda, Ryohei Kasahara, Chisato Nakamura, Yuuki Kikuchi, Akiko Hori, Gary J. Richards y Osamu Kitagawa. "Catalytic Enantioselective Synthesis of N-C Axially Chiral N-(2,6-Disubstituted-phenyl)sulfonamides through Chiral Pd-Catalyzed N-Allylation". Molecules 27, n.º 22 (13 de noviembre de 2022): 7819. http://dx.doi.org/10.3390/molecules27227819.

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Recently, catalytic enantioselective syntheses of N-C axially chiral compounds have been reported by many groups. Most N-C axially chiral compounds prepared through a catalytic asymmetric reaction possess carboxamide or nitrogen-containing aromatic heterocycle skeletons. On the other hand, although N-C axially chiral sulfonamide derivatives are known, their catalytic enantioselective synthesis is relatively underexplored. We found that the reaction (Tsuji–Trost allylation) of allyl acetate with secondary sulfonamides bearing a 2-arylethynyl-6-methylphenyl group on the nitrogen atom proceeds with good enantioselectivity (up to 92% ee) in the presence of (S,S)-Trost ligand-(allyl-PdCl)2 catalyst, affording rotationally stable N-C axially chiral N-allylated sulfonamides. Furthermore, the absolute stereochemistry of the major enantiomer was determined by X-ray single crystal structural analysis and the origin of the enantioselectivity was considered.
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2

Zhang, Xiaoke, Ya-Zhou Liu, Huawu Shao y Xiaofeng Ma. "Advances in Atroposelectively De Novo Synthesis of Axially Chiral Heterobiaryl Scaffolds". Molecules 27, n.º 23 (3 de diciembre de 2022): 8517. http://dx.doi.org/10.3390/molecules27238517.

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Axially chiral heterobiaryl frameworks are privileged structures in many natural products, pharmaceutically active molecules, and chiral ligands. Therefore, a variety of approaches for constructing these skeletons have been developed. Among them, de novo synthesis, due to its highly convergent and superior atom economy, serves as a promising strategy to access these challenging scaffolds including C-N, C-C, and N-N chiral axes. So far, several elegant reviews on the synthesis of axially chiral heterobiaryl skeletons have been disclosed, however, atroposelective construction of the heterobiaryl subunits by de novo synthesis was rarely covered. Herein, we summarized the recent advances in the catalytic asymmetric synthesis of the axially chiral heterobiaryl scaffold via de novo synthetic strategies. The related mechanism, scope, and applications were also included.
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3

Shi, Lei, Jiawei Zhu, Biqiong Hong y Zhenhua Gu. "A Chiral Relay Race: Stereoselective Synthesis of Axially Chiral Biaryl Diketones through Ring-Opening of Optical Dihydrophenan-threne-9,10-diols". Molecules 28, n.º 16 (8 de agosto de 2023): 5956. http://dx.doi.org/10.3390/molecules28165956.

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We report herein a point-to-axial chirality transfer reaction of optical dihydrophenanthrene-9,10-diols for the synthesis of axially chiral diketones. Two sets of conditions, namely a basic tBuOK/air atmosphere and an acidic NaClO/n-Bu4NHSO4, were developed to oxidatively cleave the C-C bond, resulting in the formation of axially chiral biaryl diketones. Finally, brief synthetic applications of the obtained chiral aryl diketones were demonstrated.
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4

Corti, Vasco y Giulio Bertuzzi. "Organocatalytic Asymmetric Methodologies towards the Synthesis of Atropisomeric N-Heterocycles". Synthesis 52, n.º 17 (15 de junio de 2020): 2450–68. http://dx.doi.org/10.1055/s-0040-1707814.

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A perspective on the literature dealing with the organocatalytic asymmetric preparation of axially chiral N-heterocycles is provided. A particular focus is devoted to rationalize the synthetic strategies employed in each case. Moreover, specific classes of organocatalysts are shown to stand out as privileged motives for the stereoselective preparation of such synthetically challenging molecular architectures. Finally, an overview of the main trends in the field is given.1 Introduction2 Five-Membered Rings2.1 Arylation2.2 Dynamic Kinetic Resolution2.3 Ring Construction2.4 Central-to-Axial Chirality Conversion and Chirality Transfer2.5 Desymmetrization3 Six-Membered Rings3.1 Desymmetrization3.2 (Dynamic) Kinetic Resolution3.3 Ring Construction3.4 Central-to-Axial Chirality Conversion4 Conclusion
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5

Peerlings, H. W. I. y E. W. Meijer. "Synthesis and Characterization of Axially Chiral Molecules Containing Dendritic Substituents". European Journal of Organic Chemistry 1998, n.º 4 (abril de 1998): 573–77. http://dx.doi.org/10.1002/(sici)1099-0690(199804)1998:4<573::aid-ejoc573>3.0.co;2-n.

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6

Zeindlhofer, Veronika, Phillip Hudson, Ádám Márk Pálvölgyi, Matthias Welsch, Mazin Almarashi, H. Lee Woodcock, Bernard Brooks, Katharina Bica-Schröder y Christian Schröder. "Enantiomerization of Axially Chiral Biphenyls: Polarizable MD Simulations in Water and Butylmethylether". International Journal of Molecular Sciences 21, n.º 17 (28 de agosto de 2020): 6222. http://dx.doi.org/10.3390/ijms21176222.

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In this study, we investigate the influence of chiral and achiral cations on the enantiomerization of biphenylic anions in n-butylmethylether and water. In addition to the impact of the cations and solvent molecules on the free energy profile of rotation, we also explore if chirality transfer between a chiral cation and the biphenylic anion is possible, i.e., if pairing with a chiral cation can energetically favour one conformer of the anion via diastereomeric complex formation. The quantum-mechanical calculations are accompanied by polarizable MD simulations using umbrella sampling to study the impact of solvents of different polarity in more detail. We also discuss how accurate polarizable force fields for biphenylic anions can be constructed from quantum-mechanical reference data.
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7

Wang, Jiaming, Changgui Zhao y Jian Wang. "Recent Progress toward the Construction of Axially Chiral Molecules Catalyzed by an N-heterocyclic Carbene". ACS Catalysis 11, n.º 20 (28 de septiembre de 2021): 12520–31. http://dx.doi.org/10.1021/acscatal.1c03459.

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8

Suzuki, Yuya, Masato Kageyama, Ryuichi Morisawa, Yasuo Dobashi, Hiroshi Hasegawa, Satoshi Yokojima y Osamu Kitagawa. "The synthesis of optically active N–C axially chiral tetrahydroquinoline and its response to an acid-accelerated molecular rotor". Chemical Communications 51, n.º 56 (2015): 11229–32. http://dx.doi.org/10.1039/c5cc03659c.

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9

Matsui, Ryosuke, Erina Niijima, Tomomi Imai, Hiroyuki Kobayashi, Akiko Hori, Azusa Sato, Yuko Nakamura y Osamu Kitagawa. "Intermolecular Halogen Bond Detected in Racemic and Optically Pure N-C Axially Chiral 3-(2-Halophenyl)quinazoline-4-thione Derivatives". Molecules 27, n.º 7 (6 de abril de 2022): 2369. http://dx.doi.org/10.3390/molecules27072369.

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The halogen bond has been widely used as an important supramolecular tool in various research areas. However, there are relatively few studies on halogen bonding related to molecular chirality. 3-(2-Halophenyl)quinazoline-4-thione derivatives have stable atropisomeric structures due to the rotational restriction around an N-C single bond. In X-ray single crystal structures of the racemic and optically pure N-C axially chiral quinazoline-4-thiones, we found that different types of intermolecular halogen bonds (C=S⋯X) are formed. That is, in the racemic crystals, the intermolecular halogen bond between the ortho-halogen atom and sulfur atom was found to be oriented in a periplanar conformation toward the thiocarbonyl plane, leading to a syndiotactic zig-zag array. On the other hand, the halogen bond in the enantiomerically pure crystals was oriented orthogonally toward the thiocarbonyl plane, resulting in the formation of a homochiral dimer. These results indicate that the corresponding racemic and optically pure forms in chiral molecules are expected to display different halogen bonding properties, respectively, and should be separately studied as different chemical entities.
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10

Krishnamurthy, M. S. y Noor Shahina Begum. "Crystal structure of ethyl 2-cyano-3-[(1-ethoxyethylidene)amino]-5-(3-methoxyphenyl)-7-methyl-5H-1,3-thiazolo[3,2-a]pyrimidine-6-carboxylate". Acta Crystallographica Section E Crystallographic Communications 71, n.º 4 (25 de marzo de 2015): o256—o257. http://dx.doi.org/10.1107/s2056989015005241.

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In the title compound, C22H24N4O4S, the central pyrimidine ring adopts a sofa conformation with the ring-junction N atom displaced by 0.2358 (6) Å from the mean plane of the remaining ring atoms. The 3-methoxyphenyl ring, at the chiral C atom opposite the other N atom, is positioned axially and is inclined to the thiazolopyrimidine ring with a dihedral angle of 83.88 (7)°. The thiazole ring is essentially planar (r.m.s. deviation = 0.0034 Å). In the crystal, pairs of weak C—H...O hydrogen bonds link molecules related by twofold rotation axes to formR22(8) rings, which in turn are linked by weak C—H...N interactions, forming ribbons along [-110]. In addition, π–π stacking interactions [centroid—centroid distance = 3.5744 (15) Å] connect the ribbons, forming slabs lying parallel to (001).
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11

Torii, Masahiro, Kohsuke Kato, Daisuke Uraguchi y Takashi Ooi. "Chiral ammonium betaine-catalyzed asymmetric Mannich-type reaction of oxindoles". Beilstein Journal of Organic Chemistry 12 (28 de septiembre de 2016): 2099–103. http://dx.doi.org/10.3762/bjoc.12.199.

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A highly diastereo- and enantioselective Mannich-type reaction of 3-aryloxindoles with N-Boc aldimines was achieved under the catalysis of axially chiral ammonium betaines. This catalytic method provides a new tool for the construction of consecutive quaternary and tertiary stereogenic carbon centers on biologically intriguing molecular frameworks with high fidelity.
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12

Tribedi, Soumi y Raghavan B. Sunoj. "Molecular insights into chirality transfer from double axially chiral phosphoric acid in a synergistic enantioselective intramolecular amination". Chemical Science 13, n.º 5 (2022): 1323–34. http://dx.doi.org/10.1039/d1sc05749a.

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The origin of enantiocontrol in an intramolecular amination involving Pd(PPh3)4 and a double axially chiral phosphoric acid (DAPCy) dual catalytic system is traced to a more effective series of noncovalent interactions in the lower energy C–N bond formation transition state.
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13

Zhang, Ming-Xing, Xin Chen, Kun-Lin Huang, Yi Zhu y Shan-Shan Yang. "Distinct chiral units from an axially prochiral ligand in a photoluminescent zinc(II)–organic complex". Acta Crystallographica Section C Crystal Structure Communications 68, n.º 4 (3 de marzo de 2012): m90—m93. http://dx.doi.org/10.1107/s0108270112006051.

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The asymmetric unit of the title compound, poly[(dimethylamine-κN)[μ3-(E)-2,6-dimethyl-4-styrylpyridine-3,5-dicarboxylato-κ3O3:O3′:O5]zinc(II)], [Zn(C17H13NO4)(C2H7N)]n, consists of one crystallographically independent distorted tetrahedral ZnIIcation, one (E)-2,6-dimethyl-4-styrylpyridine-3,5-dicarboxylate (mspda2−) ligand and one coordinated dimethylamine molecule. TwoS- andR-type chiral units are generated from the axially prochiral mspda2−ligand through C—H...O hydrogen bonds. TheR-type chiral units assemble a left-handed (M) Zn–mspda helical chain, while the right-handed (P) Zn–mspda helical chain is constructed from neighbouringS-type chiral units. TheP- andM-type helical chains are interlinked by carboxylate O atoms to form a one-dimensional ladder. Interchain N—H...O hydrogen bonds extend these one-dimensional ladders into a two-dimensional supramolecular architecture. The title compound exhibits luminescence at λmax= 432 nm upon excitation at 365 nm.
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14

Noor, Shabana, Shintaro Suda, Tomoyuki Haraguchi, Fehmeeda Khatoon y Takashiro Akitsu. "Chiral crystallization of a zinc(II) complex". Acta Crystallographica Section E Crystallographic Communications 77, n.º 5 (23 de abril de 2021): 542–46. http://dx.doi.org/10.1107/s2056989021003650.

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The compound, {6,6′-dimethoxy-2,2′-[(4-azaheptane-1,7-diyl)bis(nitrilomethanylidyne)]diphenolato}zinc(II) methanol monosolvate, [Zn(C22H27N3O4)]·CH3OH, at 298 K crystallizes in the orthorhombic space group Pna21. The Zn atom is coordinated by a pentadentate Schiff base ligand in a distorted trigonal–bipyramidal N3O2 geometry. The equatorial plane is formed by the two phenolic O and one amine N atom. The axial positions are occupied by two amine N atoms. The distorted bipyramidal geometry is also supported by the trigonality index (τ), which is found to be 0.85 for the molecule. In the crystal, methanol solvent molecule is connected to the complex molecule by an O—H...O hydrogen bond and the complex molecules are connected by weak supramolecular interactions, so achiral molecules generate a chiral crystal. The Hirshfeld surface analysis suggests that H...H contacts account for the largest percentage of all interactions.
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15

Zhang, Ji-Wei, Shao-Hua Xiang, Shaoyu Li y Bin Tan. "Copper-Catalyzed Synthesis of Axially Chiral Biaryls with Diaryliodonium Salts as Arylation Reagents". Molecules 26, n.º 11 (27 de mayo de 2021): 3223. http://dx.doi.org/10.3390/molecules26113223.

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NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols.
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16

Dong, Ziyang, Chengming Jiang y Changgui Zhao. "A Review on Generation and Reactivity of the N-Heterocyclic Carbene-Bound Alkynyl Acyl Azolium Intermediates". Molecules 27, n.º 22 (17 de noviembre de 2022): 7990. http://dx.doi.org/10.3390/molecules27227990.

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N-heterocyclic carbene (NHC) has been widely used as an organocatalyst for both umpolung and non-umpolung chemistry. Previous works mainly focus on species including Breslow intermediate, azolium enolate intermediate, homoenolate intermediate, alkenyl acyl azolium intermediate, etc. Notably, the NHC-bound alkynyl acyl azolium has emerged as an effective intermediate to access functionalized cyclic molecular skeleton until very recently. In this review, we summarized the generation and reactivity of the NHC-bound alkynyl acyl azolium intermediates, which covers the efforts and advances in the synthesis of achiral and axially chiral cyclic scaffolds via the NHC-bound alkynyl acyl azolium intermediates. In particular, the mechanism related to this intermediate is discussed in detail.
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17

Yang, Xiaoqun, Tingting Li, Jinli Chen, Yixian Huang, Tingwei Shen, Shiguang Li, Zhichao Jin y Shi-Chao Ren. "Carbene-Catalyzed Atroposelective Annulation for Quick Access to Axially Chiral Thiazine Derivatives". Molecules 28, n.º 10 (12 de mayo de 2023): 4052. http://dx.doi.org/10.3390/molecules28104052.

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An N-heterocyclic carbene (NHC)-catalyzed atroposelective annulation reaction is disclosed for quick and efficient access to thiazine derivatives. A series of axially chiral thiazine derivatives bearing various substituents and substitution patterns were produced in moderate to high yields with moderate to excellent optical purities. Preliminary studies revealed that some of our products exhibit promising antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) that causes rice bacterial blight.
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18

Harada, Masashi, Sachise Karakawa, Hiroshi Miyano y Kazutaka Shimbo. "Simultaneous Analysis of d,l-Amino Acids in Human Urine Using a Chirality-Switchable Biaryl Axial Tag and Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry". Symmetry 12, n.º 6 (2 de junio de 2020): 913. http://dx.doi.org/10.3390/sym12060913.

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Although d,l-amino acids are symmetrical molecules, l-isomers are generally dominant in living organisms. However, it has been found that some d-amino acids also have biological functions. A new method for simultaneously analyzing d,l-amino acids in biological samples is required to allow unknown functions of d-amino acids to be investigated. d-Amino acids in urine are currently receiving increasing amounts of attention, particularly for screening for chronic kidney diseases. However, simultaneously analyzing d,l-amino acids in human urine is challenging because of interfering unknown compounds in urine. In this study, the axially chiral derivatizing agent (R)-4-nitrophenyl-N-[2-(diethylamino)-6,6-dimethyl-[1,1-biphenyl]-2-yl] carbamate hydrochloride was used to allow enantiomers of amino acids in human urine to be simultaneously determined by liquid chromatography electrospray ionization tandem mass spectrometry. The optimized method gave good linearities, precision results, and recoveries for 18 proteinogenic amino acids and their enantiomers and glycine. The chiral-switching method using (S)-4-nitrophenyl-N-[2-(diethylamino)-6, 6-dimethyl-[1,1-biphenyl]-2-yl]carbamate hydrochloride confirmed the expected concentrations of 32 of the 37 analytes. The method was successfully used to determine the concentrations of d-serine, d-alanine, d-asparagine, d-allothreonine, d-lysine, and the d-isomers of 10 other amino acids in five human volunteer urine samples.
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19

Toze, Flavien A. A., Vladimir P. Zaytsev, Lala V. Chervyakova, Elisaveta A. Kvyatkovskaya, Pavel V. Dorovatovskii y Victor N. Khrustalev. "Crystal structure of 3-benzyl-2-[(E)-2-(furan-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one and 3-benzyl-2-[(E)-2-(thiophen-2-yl)ethenyl]-2,3-dihydroquinazolin-4(1H)-one from synchrotron X-ray diffraction". Acta Crystallographica Section E Crystallographic Communications 74, n.º 1 (1 de enero de 2018): 10–14. http://dx.doi.org/10.1107/s2056989017017479.

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The chiral title compounds, C21H18N2O2, (I), and C21H18N2OS, (II) – products of the three-component reaction between benzylamine, isatoic anhydride and furyl- or thienyl-acrolein – are isostructural and form isomorphous racemic crystals. The tetrahydropyrimidine ring in (I) and (II) adopts a sofa conformation. The amino N atom has a trigonal–pyramidal geometry [sum of the bond angles is 347.0° for both (I) and (II)], whereas the amido N atom is flat [sum of the bond angles is 359.3° for both (I) and (II)]. The furyl- and thienylethenyl substituents in (I) and (II) are planar and the conformation about the bridging C=C bond isE. These bulky fragments occupy the axial position at the quaternary C atom of the tetrahydropyrimidine ring, apparently, due to steric reasons. In the crystals, molecules of (I) and (II) form hydrogen-bonded helicoidal chains propagating along [010] by strong intermolecular N—H...O hydrogen bonds.
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20

Sato, Yasuhiro, Yuichi Kawata, Shungo Yasui, Yoshihito Kayaki y Takao Ikariya. "New Bifunctional Bis(azairidacycle) with Axial Chirality via Double Cyclometalation of 2,2′-Bis(aminomethyl)-1,1′-binaphthyl". Molecules 26, n.º 4 (22 de febrero de 2021): 1165. http://dx.doi.org/10.3390/molecules26041165.

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As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C–N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5–C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C–H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.
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21

Soloshonok, Vadim A., José Luis Aceña, Hisanori Ueki y Jianlin Han. "Design and synthesis of quasi-diastereomeric molecules with unchanging central, regenerating axial and switchable helical chirality via cleavage and formation of Ni(II)–O and Ni(II)–N coordination bonds". Beilstein Journal of Organic Chemistry 8 (13 de noviembre de 2012): 1920–28. http://dx.doi.org/10.3762/bjoc.8.223.

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We describe herein the design and synthesis of asymmetric, pentadentate ligands, which are able to coordinate to Ni(II) cations leading to quasi-diastereomeric complexes displaying two new elements of chirality: stereogenic axis and helix along with configurational stabilization of the stereogenic center on the nitrogen. Due to the stereocongested structural characteristics of the corresponding Ni(II) complexes, the formation of quasi-diastereomeric products is highly stereoselective providing formation of only two, (R a*,M h*,R c*) and (R a*,P h*,R c*), out of the four possible stereochemical combinations. The reversible quasi-diastereomeric transformation between the products (R a*,M h*,R c*) and (R a*,P h*,R c*) occurs by intramolecular trans-coordination of Ni–NH and Ni–O bonds providing a basis for a chiral switch model.
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22

Roshchin, Alexander I. y Remir G. Kostyanovsky. "Configurationally stable axially chiral N,N’-dialkyl-2,2’-biphenylene-N,N’-ureas". Mendeleev Communications 13, n.º 6 (enero de 2003): 275–76. http://dx.doi.org/10.1070/mc2003v013n06abeh001749.

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23

Kikuchi, Yuki, Chisato Nakamura, Mizuki Matsuoka, Rina Asami y Osamu Kitagawa. "Catalytic Enantioselective Synthesis of N–C Axially Chiral Sulfonamides through Chiral Palladium-Catalyzed N-Allylation". Journal of Organic Chemistry 84, n.º 12 (22 de mayo de 2019): 8112–20. http://dx.doi.org/10.1021/acs.joc.9b00989.

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24

Brunner, H., G. Olschewski y B. Nuber. "Enantioselective Catalyses; 126: Axially Chiral N,N-Ligands with Binaphthyl/Bipyridyl Structure". Synthesis 1999, n.º 03 (marzo de 1999): 429–34. http://dx.doi.org/10.1055/s-1999-3424.

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25

Kawabata, Takeo, Changsheng Jiang, Kazuhiro Hayashi, Kazunori Tsubaki, Tomoyuki Yoshimura, Swapan Majumdar, Takahiro Sasamori y Norihiro Tokitoh. "Axially Chiral Binaphthyl Surrogates with an Inner N−H−N Hydrogen Bond". Journal of the American Chemical Society 131, n.º 1 (14 de enero de 2009): 54–55. http://dx.doi.org/10.1021/ja808213r.

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26

Vekemans, Jozef A. J. M., Jeroen A. F. Boogers y Henk M. Buck. "Conformational interlocking in axially chiral methyl N-(2',4'-dimethylnicotinoyl)-N-methylphenylalaninates". Journal of Organic Chemistry 56, n.º 1 (enero de 1991): 10–16. http://dx.doi.org/10.1021/jo00001a005.

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27

Koide, Hiroshige, Motokazu Uemura y Motokazu Uemura. "Synthesis of axially chiral N,N-diethyl 2,6-disubstituted benzamides utilizing planar chiral (arene)chromium complexes". Chemical Communications, n.º 22 (1998): 2483–84. http://dx.doi.org/10.1039/a806064i.

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28

Kotora, Martin. "Synthesis of axially chiral bipyridine N,N'-dioxides and enantioselective allylation of aldehydes". Pure and Applied Chemistry 82, n.º 9 (7 de junio de 2010): 1813–26. http://dx.doi.org/10.1351/pac-con-09-10-01.

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N-oxides possessing the pyridine framework are strong Lewis bases that can activate the C–Si bond of allylhalosilanes to such an extent that they catalyze reactions with aldehydes. N-oxides embedded in chiral scaffolds are usually capable of highly selective chirality transfer to the derived products. Our goal was to develop a general synthetic method allowing the preparation of structurally varied N,N'-dioxides suitable for enantioselective organocatalysis. The underlying synthetic strategy was based on [2 + 2 + 2]-cyclotrimerization of suitably substituted diynes with nitriles catalyzed by Co-complexes to generate the desired bipyridines, their further oxidation and resolution of which furnished the corresponding chiral N,N'-dioxides. The prepared compounds were used in catalytic allylation of aromatic aldehydes to homoallyl alcohols with high enantioselectivity (up to 96 % ee). Enantioselectivity, enantiodiscrimination, and the reaction mechanism are controlled by the choice of solvent.
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29

Pan, Ming, Ying-Bo Shao, Qun Zhao y Xin Li. "Asymmetric Synthesis of N–N Axially Chiral Compounds by Phase-Transfer-Catalyzed Alkylations". Organic Letters 24, n.º 1 (20 de diciembre de 2021): 374–78. http://dx.doi.org/10.1021/acs.orglett.1c04028.

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30

Frey, Johanna, Sabine Choppin, Françoise Colobert y Joanna Wencel-Delord. "Towards Atropoenantiopure N–C Axially Chiral Compounds via Stereoselective C–N Bond Formation". CHIMIA International Journal for Chemistry 74, n.º 11 (25 de noviembre de 2020): 883–89. http://dx.doi.org/10.2533/chimia.2020.883.

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N–C axial chirality, although disregarded for decades, is an interesting type of chirality with appealing applications in medicinal chemistry and agrochemistry. However, atroposelective synthesis of optically pure compounds is extremely challenging and only a limited number of synthetic routes have been designed. In particular, asymmetric N-arylation reactions allowing atroposelective N–C bond forming events remain scarce, although great advances have been achieved recently. In this minireview we summarize the synthetic approaches towards synthesis of N–C axially chiral compounds via stereocontrolled N–C bond forming events. Both organo-catalyzed and metal-catalyzed transformations are described, thus illustrating the diversity and specificity of both strategies.
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31

Wu, Shijie, Yongfei Xing, Jie Wang, Xingchen Guo, Huajie Zhu y Wan Li. "Axially chiral N,N′‐ dioxides ethers for catalysis in enantioselective allylation of aldehydes". Chirality 31, n.º 11 (28 de agosto de 2019): 947–57. http://dx.doi.org/10.1002/chir.23122.

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32

Ye, Chen‐Xi, Shuming Chen, Feng Han, Xiulan Xie, Sergei Ivlev, K. N. Houk y Eric Meggers. "Atroposelective Synthesis of Axially Chiral N‐Arylpyrroles by Chiral‐at‐Rhodium Catalysis". Angewandte Chemie 132, n.º 32 (3 de junio de 2020): 13654–58. http://dx.doi.org/10.1002/ange.202004799.

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33

Ye, Chen‐Xi, Shuming Chen, Feng Han, Xiulan Xie, Sergei Ivlev, K. N. Houk y Eric Meggers. "Atroposelective Synthesis of Axially Chiral N‐Arylpyrroles by Chiral‐at‐Rhodium Catalysis". Angewandte Chemie International Edition 59, n.º 32 (3 de junio de 2020): 13552–56. http://dx.doi.org/10.1002/anie.202004799.

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34

Nakazaki, Atsuo, Keitaro Miyagawa, Noriaki Miyata y Toshio Nishikawa. "ChemInform Abstract: Synthesis of a C-N Axially Chiral N-Arylisatin Through Asymmetric Intramolecular N-Arylation." ChemInform 46, n.º 48 (12 de noviembre de 2015): no. http://dx.doi.org/10.1002/chin.201548124.

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35

García-González, Ángel, Leland Belda, Alejandro Manchado, Carlos T. Nieto y Narciso Martín Garrido. "(R)-N-Benzyl-N-(1-phenylethyl)cyclohexanamine". Molbank 2023, n.º 1 (20 de enero de 2023): M1561. http://dx.doi.org/10.3390/m1561.

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The preparation and characterization of a new chiral tertiary dibenzylamine are described. These molecules are well known in the literature for their high neuropharmacological potential. The general synthetic pathway is based on asymmetric Aza–Michael addition of chiral (R)-N-benzyl-N-(α-methylbenzyl)amide to methyl cyclohex-1-en-carboxilate obtaining the β-amino ester, followed by carboxylic acid hydrolysis and subsequent Barton descarboxylation. Interestingly, it is a general synthetic procedure of a wide range of chiral amines by careful choice of insaturated esters and alkylation of the chiral enolate in the initial reaction. The new tertiary dibenzylamine molecule is fully characterized by NMR Spectroscopy (1H and 13C), as well by High-Resolution Mass Spectrometry and Infrared Spectroscopy.
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36

Chen, Jin-fang, Jin-yi Shi, Cong-cong Yin, Xin Cui, Guang-xun Li, Zhuo Tang y Jin-zhong Zhao. "Synthesis of axially chiral N-aryl benzimidazoles via chiral phosphoric acid catalyzed enantioselective oxidative aromatization". New Journal of Chemistry 46, n.º 14 (2022): 6398–402. http://dx.doi.org/10.1039/d1nj06092a.

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N-aryl benzimidazoline produced in situ was used as a H2 donor, which was converted to C–N axially chiral N-aryl benzimidazole by CPA-catalyzed enantioselective transfer hydrogenation of the in situ produced imine.
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37

Kinoshita, Shunsuke y Ken Kamikawa. "Stereoselective synthesis of N-arylindoles and related compounds with axially chiral N–C bonds". Tetrahedron 72, n.º 34 (agosto de 2016): 5202–7. http://dx.doi.org/10.1016/j.tet.2015.11.053.

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38

FUJII, M. y A. HONDA. "ChemInform Abstract: Preparation of an Axially Chiral Heteroaromatic Compound 1,1′- Biisoquinoline-N,N′-dioxide." ChemInform 23, n.º 31 (21 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199231195.

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39

Kamikawa, K., M. Uemura, S. Kinoshita y H. Matsuzaka. "Formation of Axially Chiral N-Aryl Indoles and Stereoselective Functionalization". Synfacts 2006, n.º 5 (mayo de 2006): 0466. http://dx.doi.org/10.1055/s-2006-934353.

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40

Shimizu, Ken D., Heather O. Freyer y Richard D. Adams. "Synthesis, resolution and structure of axially chiral atropisomeric N-arylimides". Tetrahedron Letters 41, n.º 29 (julio de 2000): 5431–34. http://dx.doi.org/10.1016/s0040-4039(00)00835-2.

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41

Rokade, Balaji V. y Patrick J. Guiry. "Axially Chiral P,N-Ligands: Some Recent Twists and Turns". ACS Catalysis 8, n.º 1 (26 de diciembre de 2017): 624–43. http://dx.doi.org/10.1021/acscatal.7b03759.

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42

Lin, Wei, Qun Zhao, Yao Li, Ming Pan, Chen Yang, Guo-Hui Yang y Xin Li. "Asymmetric synthesis of N–N axially chiral compounds via organocatalytic atroposelective N-acylation". Chemical Science 13, n.º 1 (2022): 141–48. http://dx.doi.org/10.1039/d1sc05360d.

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A highly efficient atroposelective N-acylation reaction of quinazolinone type benzamides with cinnamic anhydrides for the direct catalytic synthesis of optically active atropisomeric quinazolinone derivatives was developed.
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43

Koide, Hiroshige y Motokazu Uemura. "Axially chiral benzamides: Diastereoselective nucleophilic additions to planar chiral (N, N-diethyl-2-acyl-6-methylbenzamide)chromium complexes". Tetrahedron Letters 40, n.º 17 (abril de 1999): 3443–46. http://dx.doi.org/10.1016/s0040-4039(99)00462-1.

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44

Zhou, Qian-Yi y Xin Li. "Atroposelective construction of axially chiral enamides via N-allylic alkylation". Chemical Communications 58, n.º 30 (2022): 4727–30. http://dx.doi.org/10.1039/d2cc01000c.

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45

Ren, Qiao, Tingting Cao, Chunnian He, Meihua Yang, Haitao Liu y Lei Wang. "Highly Atroposelective Rhodium(II)-Catalyzed N–H Bond Insertion: Access to Axially Chiral N-Arylindolocarbazoles". ACS Catalysis 11, n.º 10 (6 de mayo de 2021): 6135–40. http://dx.doi.org/10.1021/acscatal.1c01232.

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46

Brunner, H., G. Olschewski y B. Nuber. "ChemInform Abstract: Enantioselective Catalyses. Part 126. Axially Chiral N,N-Ligands with Binaphthyl/Bipyridyl Structure." ChemInform 30, n.º 27 (15 de junio de 2010): no. http://dx.doi.org/10.1002/chin.199927158.

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47

Kotora, Martin. "ChemInform Abstract: Synthesis of Axially Chiral Bipyridine N,N′-Dioxides and Enantioselective Allylation of Aldehydes". ChemInform 42, n.º 9 (3 de febrero de 2011): no. http://dx.doi.org/10.1002/chin.201109268.

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48

Yang, Guo-Hui, Hanliang Zheng, Xin Li y Jin-Pei Cheng. "Asymmetric Synthesis of Axially Chiral Phosphamides via Atroposelective N-Allylic Alkylation". ACS Catalysis 10, n.º 3 (17 de enero de 2020): 2324–33. http://dx.doi.org/10.1021/acscatal.9b05443.

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49

Brown, Richard J., Gary Annis, Albert Casalnuovo, Dominic Chan, Rafael Shapiro y William J. Marshall. "Synthesis and properties of axially-chiral N-(2,6-disubstituted)phenyl triazolones". Tetrahedron 60, n.º 20 (mayo de 2004): 4361–75. http://dx.doi.org/10.1016/j.tet.2004.03.056.

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50

Li, Dawei, Sijing Wang, Shulin Ge, Shunxi Dong y Xiaoming Feng. "Asymmetric Synthesis of Axially Chiral Anilides via Organocatalytic Atroposelective N-Acylation". Organic Letters 22, n.º 14 (30 de junio de 2020): 5331–36. http://dx.doi.org/10.1021/acs.orglett.0c01581.

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