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Search for "atropoisomers" in Full Text gives 4 result(s) in Beilstein Journal of Organic Chemistry.
Recent advances in organocatalytic atroposelective reactions
- Henrich Szabados and
- Radovan Šebesta
Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6
- acids feature as the most prolific catalytic structure. The last part of the article discusses hydrogen-bond-donating catalysts and other catalyst motifs such as phase-transfer catalysts. Keywords: asymmetric organocatalysis; atropoisomers; atroposelective synthesis; axial chirality; stereogenic axis
- -axial chirality conversion and formation of axially chiral products 21a–e (Scheme 7). This critical aromatization was later studied in more detail, and the team was able to achieve enantiodivergent aromatization, which led to different atropoisomers based on the oxidation reagent used [26]. The use of
- NBS and AgOTf led to the formation of the (Sa)-atropoisomers, whereas NIS afforded the (Ra)-atropoisomers. Non-biaryl atropoisomers are characterized by at least one non-aryl substituent on the stereogenic axis. Among them, compounds featuring a conformationally stable C(sp2)–C(sp3) stereogenic axis
Graphical Abstract
Scheme 1: Formation of axially chiral styrenes 3 via iminium activation.
Scheme 2: Synthesis of axially chiral 2-arylquinolines 6.
Scheme 3: Atroposelective intramolecular (4 + 2) annulation leading to aryl-substituted indolines.
Scheme 4: Atroposelective formation of biaryl via twofold aldol condensation.
Scheme 5: Strategy towards diastereodivergent formation of axially chiral oligonaphthylenes.
Scheme 6: Atroposelective formation of chiral biaryls based on a Michael/Henry domino reaction.
Scheme 7: Organocatalytic Michael/aldol cascade followed by oxidative aromatization.
Scheme 8: Atroposelective formation of C(sp2)–C(sp3) axially chiral compounds.
Scheme 9: NHC-catalyzed synthesis of axially chiral styrenes 26.
Scheme 10: NHC-catalyzed synthesis of biaxial chiral pyranones.
Scheme 11: Formation of bridged biaryls with eight-membered lactones.
Scheme 12: The NHC-catalyzed (3 + 2) annulation of urazoles 37 and ynals 36.
Scheme 13: NHC-catalyzed synthesis of axially chiral 4‑aryl α‑carbolines 41.
Scheme 14: NHC-catalyzed construction of N–N-axially chiral pyrroles and indoles.
Scheme 15: NHC-catalyzed oxidative Michael–aldol cascade.
Scheme 16: NHC-catalyzed (4 + 2) annulation for the synthesis of benzothiophene-fused biaryls.
Scheme 17: NHC-catalyzed desymmetrization of N-aryl maleimides.
Scheme 18: NHC-catalyzed deracemization of biaryl hydroxy aldehydes 55a–k into axially chiral benzonitriles 56a...
Scheme 19: NHC-catalyzed desymmetrization of 2-aryloxyisophthalaldehydes.
Scheme 20: NHC-catalyzed DKR of 2-arylbenzaldehydes 62.
Scheme 21: Atroposelective biaryl amination.
Scheme 22: CPA-catalyzed atroposelective amination of 2-anilinonaphthalenes.
Scheme 23: Atroposelective DKR of naphthylindoles.
Scheme 24: CPA-catalyzed kinetic resolution of binaphthylamines.
Scheme 25: Atroposelective amination of aromatic amines with diazodicarboxylates.
Scheme 26: Atroposelective Friedländer heteroannulation.
Scheme 27: CPA-catalyzed formation of axially chiral 4-arylquinolines.
Scheme 28: CPA-catalyzed Friedländer reaction of arylketones with cyclohexanones.
Scheme 29: CPA-catalyzed atroposelective Povarov reaction.
Scheme 30: Atroposelective CPA-catalyzed Povarov reaction.
Scheme 31: Paal–Knorr formation of axially chiral N-pyrrolylindoles and N-pyrrolylpyrroles.
Scheme 32: Atroposelective Paal–Knorr reaction leading to N-pyrrolylpyrroles.
Scheme 33: Atroposelective Pictet–Spengler reaction of N-arylindoles with aldehydes.
Scheme 34: Atroposelective Pictet–Spengler reaction leading to tetrahydroisoquinolin-8-ylanilines.
Scheme 35: Atroposelective formation of arylindoles.
Scheme 36: CPA-catalyzed arylation of naphthoquinones with indolizines.
Scheme 37: Atroposelective reaction of o-naphthoquinones.
Scheme 38: CPA-catalyzed formation of axially chiral arylquinones.
Scheme 39: CPA-catalyzed axially chiral N-arylquinones.
Scheme 40: Atroposelective additions of bisindoles to isatin-based 3-indolylmethanols.
Scheme 41: CPA-catalyzed synthesis of axially chiral arylindolylindolinones.
Scheme 42: CPA-catalyzed reaction between bisindoles and ninhydrin-derived 3-indoylmethanols.
Scheme 43: Atroposelective reaction of bisindoles and isatin-derived imines.
Scheme 44: CPA-catalyzed formation of axially chiral bisindoles.
Scheme 45: Atroposelective reaction of 2-naphthols with alkynylhydroxyisoindolinones.
Scheme 46: CPA-catalyzed reaction of indolylnaphthols with propargylic alcohols.
Scheme 47: Atroposelective formation of indolylpyrroloindoles.
Scheme 48: Atroposelective reaction of indolylnaphthalenes with alkynylnaphthols.
Scheme 49: CPA-catalyzed addition of naphthols to alkynyl-2-naphthols and 2-naphthylamines.
Scheme 50: CPA-catalyzed formation of axially chiral aryl-alkene-indoles.
Scheme 51: CPA-catalyzed formation of axially chiral styrenes.
Scheme 52: Atroposelective formation of alkenylindoles.
Scheme 53: Atroposelective formation of axially chiral arylquinolines.
Scheme 54: Atroposelective (3 + 2) cycloaddition of alkynylindoles with azonaphthalenes.
Scheme 55: CPA-catalyzed formation of axially chiral 3-(1H-benzo[d]imidazol-2-yl)quinolines.
Scheme 56: Atroposelective cyclization of 3-(arylethynyl)-1H-indoles.
Scheme 57: Atroposelective three-component heteroannulation.
Scheme 58: CPA-catalyzed formation of arylbenzimidazols.
Scheme 59: CPA-catalyzed reaction of N-naphthylglycine esters with nitrosobenzenes.
Scheme 60: CPA-catalyzed formation of axially chiral N-arylbenzimidazoles.
Scheme 61: CPA-catalyzed formation of axially chiral arylbenzoindoles.
Scheme 62: CPA-catalyzed formation of pyrrolylnaphthalenes.
Scheme 63: CPA-catalyzed addition of naphthols and indoles to nitronaphthalenes.
Scheme 64: Atroposelective reaction of heterobiaryl aldehydes and aminobenzamides.
Scheme 65: Atroposelective cyclization forming N-arylquinolones.
Scheme 66: Atroposelective formation of 9H-carbazol-9-ylnaphthalenes and 1H-indol-1-ylnaphthalene.
Scheme 67: CPA-catalyzed formation of pyrazolylnaphthalenes.
Scheme 68: Atroposelective addition of diazodicarboxamides to azaborinephenols.
Scheme 69: Catalytic formation of axially chiral arylpyrroles.
Scheme 70: Atroposelective coupling of 1-azonaphthalenes with 2-naphthols.
Scheme 71: CPA-catalyzed formation of axially chiral oxindole-based styrenes.
Scheme 72: Atroposelective electrophilic bromination of aminonaphthoquinones.
Scheme 73: Atroposelective bromination of dienes.
Scheme 74: CPA-catalyzed formation of axially chiral 5-arylpyrimidines.
Scheme 75: Atroposelective hydrolysis of biaryloxazepines.
Scheme 76: Atroposelective opening of dinaphthosiloles.
Scheme 77: Atroposelective reduction of naphthylenals.
Scheme 78: Atroposelective allylic substitution with 2-naphthols.
Scheme 79: Atroposelective allylic alkylation with phosphinamides.
Scheme 80: Atroposelective allylic substitution with aminopyrroles.
Scheme 81: Atroposelective allylic substitution with aromatic sulfinamides.
Scheme 82: Atroposelective sulfonylation of naphthylynones.
Scheme 83: Squaramide-catalyzed reaction of alkynyl-2-naphthols with 5H-oxazolones.
Scheme 84: Formation of axially chiral styrenes via sulfonylative opening of cyclopropanols.
Scheme 85: Atroposelective organo-photocatalyzed sulfonylation of alkynyl-2-naphthols.
Scheme 86: Thiourea-catalyzed atroposelective cyclization of alkynylnaphthols.
Scheme 87: Squaramide-catalyzed formation of axially chiral naphthylisothiazoles.
Scheme 88: Atroposelective iodo-cyclization catalyzed by squaramide C69.
Scheme 89: Squaramide-catalyzed formation of axially chiral oligoarenes.
Scheme 90: Atroposelective ring-opening of cyclic N-sulfonylamides.
Scheme 91: Thiourea-catalyzed kinetic resolution of naphthylpyrroles.
Scheme 92: Atroposelective ring-opening of arylindole lactams.
Scheme 93: Atroposelective reaction of 1-naphthyl-2-tetralones and diarylphosphine oxides.
Scheme 94: Atroposelective reaction of iminoquinones with indoles.
Scheme 95: Kinetic resolution of binaphthylalcohols.
Scheme 96: DKR of hydroxynaphthylamides.
Scheme 97: Atroposelective N-alkylation with phase-transfer catalyst C75.
Scheme 98: Atroposelective allylic substitution via kinetic resolution of biarylsulfonamides.
Scheme 99: Atroposelective bromo-functionalization of alkynylarenes.
Scheme 100: Sulfenylation-induced atroposelective cyclization.
Scheme 101: Atroposelective O-sulfonylation of isochromenone-indoles.
Scheme 102: NHC-catalyzed atroposelective N-acylation of anilines.
Scheme 103: Peptide-catalyzed atroposelective ring-opening of lactones.
Scheme 104: Peptide-catalyzed coupling of 2-naphthols with quinones.
Scheme 105: Atroposelective nucleophilic aromatic substitution of fluoroarenes.
Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence
- Vânia F. Pais,
- Tristan Neumann,
- Ignacio Vayá,
- M. Consuelo Jiménez,
- Abel Ros and
- Uwe Pischel
Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254
- hinders the free rotation around axis A (Scheme 3) of the compounds 16–19; therefore, complex mixtures of the syn/anti atropoisomers (0.45:0.55; syn:anti) were observed in NMR spectroscopy. To facilitate the C–C bond rotation around axis B (Scheme 3) and simplify the NMR spectra, the measurements were
Graphical Abstract
Figure 1: Structures of the dyes 16–19.
Scheme 1: Synthesis of the precursors 2, 3, and 5.
Scheme 2: Synthesis of the precursor triflates 8–11.
Scheme 3: Synthesis of 12–15 and the organoboron dyes 16–19.
Figure 2: UV–vis absorption (solid line) and fluorescence (dashed line) spectra of a) 16, b) 17, c) 18, and d...
Scheme 4: Jablonski diagram representing the photophysical processes in the dyes 16–19.
Figure 3: Transient absorption spectrum (600 ns delay) of dye 17 in nitrogen-purged acetonitrile on excitatio...
Figure 4: Fluorescence titrations of the dyes (ca. 4–11 μM) with Bu4NF in acetonitrile. a) 16 (up to 156 equi...
Calix[6]arene-based atropoisomeric pseudo[2]rotaxanes
- Carmine Gaeta,
- Carmen Talotta and
- Placido Neri
Beilstein J. Org. Chem. 2018, 14, 2112–2124, doi:10.3762/bjoc.14.186
- axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are, respectively, the kinetic and the thermodynamic ones. Keywords: atropoisomers; calixarene; conformation; pseudorotaxane; social isomerism; Introduction Mechanomolecules [1][2][3][4], such as rotaxanes and catenanes show
- of the axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are the kinetic and thermodynamic pseudorotaxane, respectively. We do believe that novel and intriguing calixarene-based mechanomolecules, with expanded properties or functions, could be obtained by an appropriate
- pseudorotaxane atropoisomers calculated at B3LYP/6-31G(d,p) level of theory and using Grimme’s dispersion corrections (IOp(3/124 = 3)). The two pseudorotaxane atropoisomers obtained by threading hexahexyloxycalix[6]arene 1 with monostoppered alkylbenzylammonium axle 6+. The two pseudorotaxane atropoisomers
Graphical Abstract
Figure 1: Cartoon representation of the chiral rotaxane of the Goldup group [15,16] (I and I*) and of the chiral pse...
Figure 2: Cartoon representation of the rotaxane sequence isomers reported by Leigh [17] (III and IV) and of the ...
Figure 3: The possible 8 discrete conformations of a calix[6]arene macrocycle [26].
Figure 4: Diastereoisomeric pseudorotaxanes obtained by threading a directional calixarene wheel with directi...
Scheme 1: Synthesis of threads 2+ and 3+. Reagents and conditions: a) hexamethyldisilazane, LiClO4, 30 min, 6...
Figure 5:
Possible mechanism for the formation of the two atropoisomeric pseudo[2]rotaxanes 2+![[Graphic 2]](/bjoc/content/inline/1860-5397-14-186-i3.svg?max-width=637&scale=1.18182)
1cone and 2+11,...
Figure 6: 1H NMR spectra (600 MHz, CDCl3, 298 K) of, from bottom to top: hexahexyloxycalix[6]arene 1; a 1:1 m...
Figure 7:
DFT-optimized structures of the: (left) 2+1cone and (right) 2+11,2,3-alt pseudorotaxane atropoisome...
Figure 8: The two pseudorotaxane atropoisomers obtained by threading hexahexyloxycalix[6]arene 1 with monosto...
Figure 9: The two pseudorotaxane atropoisomers obtained by threading penta-O-methyl-p-tert-butylcalix[5]arene ...
Figure 10: 1H NMR spectra (600 MHz, CDCl3, 298 K) of, from bottom to top: hexahexyloxycalix[6]arene 1; a 1:1 m...
Ring strain and total syntheses of modified macrocycles of the isoplagiochin type
- Andreas Speicher,
- Timo Backes,
- Kerstin Hesidens and
- Jürgen Kolz
Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71
- . The existence of atropoisomers [3] prompted us to perform detailed studies on the chirality of 1 and 2 including HPLC-CD experiments. Assuming the existence of three formal stereogenic elements A–C (Figure 1), a total of up to 23 = 8 conformers (four diastereomers with their enantiomers) in principle
Graphical Abstract
Figure 1: Structures of isoplagiochins C (1) and D (2) (with aryl fragments a–d and possible conformational b...
Figure 2: Possible stereoisomers of 1 as conformers C1–C4 relative to the configurationally stable biaryl axi...
Scheme 1: Stereochemical correlation for 1 and 2. (*: configurationally stable, (*): configurationally semi-s...
Figure 3: Temperature dependent 1H NMR and assignment of methoxy signals in the tetramethyl ether 3.
Scheme 2: Strategy of synthesis for the macrocycles 5–7.
Scheme 3: Preparation of the terminal alkyne 13 as a–b part (TBATB = tetrabutylammonium tribromide).
Scheme 4: Sonogashira-type coupling to the tolane 16.
Scheme 5: Synthesis of the d building blocks 21 and 26. aThe original procedure in diluted ammonia [31] was repla...
Scheme 6: Synthesis of the tolane precursors 27 and 28 for cyclization.
Scheme 7: Synthesis of the modified macrocycles 5–7 from the dialdehyde precursors 28–30.
Scheme 8: Synthesis of the known macrocycle 3 via McMurry reaction.
