Search for "chiral diamines" in Full Text gives 12 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62
Graphical Abstract
Figure 1: Representative examples of bioactive natural products and FDA-approved drugs containing a pyridine ...
Scheme 1: Classical and traditional methods for the synthesis of functionalized pyridines.
Scheme 2: Rare earth metal (Ln)-catalyzed pyridine C–H alkylation.
Scheme 3: Pd-catalyzed C–H alkylation of pyridine N-oxide.
Scheme 4: CuI-catalyzed C–H alkylation of N-iminopyridinium ylides with tosylhydrazones (A) and a plausible r...
Scheme 5: Zirconium complex-catalyzed pyridine C–H alkylation.
Scheme 6: Rare earth metal-catalyzed pyridine C–H alkylation with nonpolar unsaturated substrates.
Scheme 7: Heterobimetallic Rh–Al complex-catalyzed ortho-C–H monoalkylation of pyridines.
Scheme 8: Mono(phosphinoamido)-rare earth complex-catalyzed pyridine C–H alkylation.
Scheme 9: Rhodium-catalyzed pyridine C–H alkylation with acrylates and acrylamides.
Scheme 10: Ni–Al bimetallic system-catalyzed pyridine C–H alkylation.
Scheme 11: Iridium-catalyzed pyridine C–H alkylation.
Scheme 12: para-C(sp2)–H Alkylation of pyridines with alkenes.
Scheme 13: Enantioselective pyridine C–H alkylation.
Scheme 14: Pd-catalyzed C2-olefination of pyridines.
Scheme 15: Ru-catalyzed C-6 (C-2)-propenylation of 2-arylated pyridines.
Scheme 16: C–H addition of allenes to pyridines catalyzed by half-sandwich Sc metal complex.
Scheme 17: Pd-catalyzed stereodivergent synthesis of alkenylated pyridines.
Scheme 18: Pd-catalyzed ligand-promoted selective C3-olefination of pyridines.
Scheme 19: Mono-N-protected amino acids in Pd-catalyzed C3-alkenylation of pyridines.
Scheme 20: Amide-directed and rhodium-catalyzed C3-alkenylation of pyridines.
Scheme 21: Bimetallic Ni–Al-catalyzed para-selective alkenylation of pyridine.
Scheme 22: Arylboronic ester-assisted pyridine direct C–H arylation.
Scheme 23: Pd-catalyzed C–H arylation/benzylation with toluene.
Scheme 24: Pd-catalyzed pyridine C–H arylation with potassium aryl- and heteroaryltrifluoroborates.
Scheme 25: Transient activator strategy in pyridine C–H biarylation.
Scheme 26: Ligand-promoted C3-arylation of pyridine.
Scheme 27: Pd-catalyzed arylation of nicotinic and isonicotinic acids.
Scheme 28: Iron-catalyzed and imine-directed C–H arylation of pyridines.
Scheme 29: Pd–(bipy-6-OH) cooperative system-mediated direct pyridine C3-arylation.
Scheme 30: Pd-catalyzed pyridine N-oxide C–H arylation with heteroarylcarboxylic acids.
Scheme 31: Pd-catalyzed C–H cross-coupling of pyridine N-oxides with five-membered heterocycles.
Scheme 32: Cu-catalyzed dehydrative biaryl coupling of azine(pyridine) N-oxides and oxazoles.
Scheme 33: Rh(III)-catalyzed cross dehydrogenative C3-heteroarylation of pyridines.
Scheme 34: Pd-catalyzed C3-selective arylation of pyridines.
Scheme 35: Rhodium-catalyzed oxidative C–H annulation of pyridines to quinolines.
Scheme 36: Rhodium-catalyzed and NHC-directed C–H annulation of pyridine.
Scheme 37: Ni/NHC-catalyzed regio- and enantioselective C–H cyclization of pyridines.
Scheme 38: Rare earth metal-catalyzed intramolecular C–H cyclization of pyridine to azaindolines.
Scheme 39: Rh-catalyzed alkenylation of bipyridine with terminal silylacetylenes.
Scheme 40: Rollover cyclometallation in Rh-catalyzed pyridine C–H functionalization.
Scheme 41: Rollover pathway in Rh-catalyzed C–H functionalization of N,N,N-tridentate chelating compounds.
Scheme 42: Pd-catalyzed rollover pathway in bipyridine-6-carboxamides C–H arylation.
Scheme 43: Rh-catalyzed C3-acylmethylation of bipyridine-6-carboxamides with sulfoxonium ylides.
Scheme 44: Rh-catalyzed C–H functionalization of bipyridines with alkynes.
Scheme 45: Rh-catalyzed C–H acylmethylation and annulation of bipyridine with sulfoxonium ylides.
Scheme 46: Iridium-catalyzed C4-borylation of pyridines.
Scheme 47: C3-Borylation of pyridines.
Scheme 48: Pd-catalyzed regioselective synthesis of silylated dihydropyridines.
Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51
Graphical Abstract
Figure 1: Design of PKS-inspired multifunctional amino-thiourea macrocycle catalysts.
Scheme 1: Synthesis of tetraamino-bisthiourea chiral macrocycles M1–M12. The synthesis of M1, M5, M7, and M8 ...
Scheme 2: Substrate scope of isatin imines. Reaction conditions: 6 (0.2 mmol), 7a (0.3 mmol), and 5 mol % M3 ...
Scheme 3: Substrate scope of MAHTs. Reaction conditions: 6a (0.2 mmol), 7 (0.3 mmol), and 5 mol % M3 in 2 mL ...
Figure 2: Proposed catalytic mechanism.
Beilstein J. Org. Chem. 2019, 15, 1289–1297, doi:10.3762/bjoc.15.127
Graphical Abstract
Figure 1: Рharmacologically active sulfones.
Figure 2: Structures of the ligands L1–L8.
Figure 3: Evolution of the conversion of 5 and diastereomeric composition of the products of reaction of 5a w...
Figure 4: Time profile of epimerization and retro-Michael reaction of (2R,3S)-8a in chloroform-d solution.
Figure 5: ORTEP diagram of (2R,3S)-8d.
Scheme 1: The proposed mechanism of asymmetric addition of β-ketosulfones to nitroalkenes.
Scheme 2: Transition state models for asymmetric addition of β-ketosulfones to nitroalkenes.
Beilstein J. Org. Chem. 2018, 14, 634–641, doi:10.3762/bjoc.14.50
Graphical Abstract
Scheme 1: Synthesis of macrocyclic derivative 4.
Figure 1: Possible route to sucrose cryptands 6.
Figure 2: Possible route to dienes of type 9.
Scheme 2: Unsuccessful attempts to amines 12a and 13b.
Scheme 3: Syntheses of "elongated" amines 17 and 18.
Scheme 4: Synthesis of macrocycle 25.
Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178
Graphical Abstract
Scheme 1: a) Schematic representations of unsubstituted urea, thiourea and guanidine. b) Wöhler's synthesis o...
Figure 1: Antidiabetic (1–3) and antimalarial (4) drugs derived from ureas and guanidines currently available...
Scheme 2: The structures of some representative (thio)urea and guanidine organocatalysts 5–8 and anion sensor...
Scheme 3: Solid-state reactivity of isothiocyanates reported by Kaupp [30].
Scheme 4: a) Mechanochemical synthesis of aromatic and aliphatic di- and trisubstituted thioureas by click-co...
Figure 2: The supramolecular level of organization of thioureas in the solid-state.
Figure 3: The supramolecular level of organization of thioureas in the solid-state.
Scheme 5: Thiourea-based organocatalysts and anion sensors obtained by click-mechanochemical synthesis.
Scheme 6: Mechanochemical desymmetrization of ortho-phenylenediamine.
Scheme 7: Mechanochemical desymmetrization of para-phenylenediamine.
Scheme 8: a) Selected examples of a mechanochemical synthesis of aromatic isothiocyanates from anilines. b) O...
Scheme 9: In solution, aromatic N-thiocarbamoyl benzotriazoles 27 are unstable and decompose to isothiocyanat...
Scheme 10: Mechanosynthesis of a) bis-thiocarbamoyl benzotriazole 29 and b) benzimidazole thione 31. c) Synthe...
Figure 4: In situ Raman spectroscopy monitoring the synthesis of thiourea 28d in the solid-state. N-Thiocarba...
Scheme 11: a) The proposed synthesis of monosubstituted thioureas 32. b) Conversion of N-thiocarbamoyl benzotr...
Scheme 12: A few examples of mechanochemical amination of thiocarbamoyl benzotriazoles by in situ generated am...
Scheme 13: Mechanochemical synthesis of a) anion binding urea 33 by amine-isocyanate coupling and b) dialkylur...
Scheme 14: a) Solvent-free milling synthesis of the bis-urea anion sensor 35. b) Non-selective desymmetrizatio...
Scheme 15: a) HOMO−1 contours of mono-thiourea 19b and mono-urea 36. b) Mechanochemical synthesis of hybrid ur...
Scheme 16: Synthesis of ureido derivatives 38 and 39 from KOCN and hydrochloride salts of a) L-phenylalanine m...
Scheme 17: a) K2CO3-assisted synthesis of sulfonyl (thio)ureas. b) CuCl-catalyzed solid-state synthesis of sul...
Scheme 18: Two-step mechanochemical synthesis of the antidiabetic drug glibenclamide (2).
Scheme 19: Derivatization of saccharin by mechanochemical CuCl-catalyzed addition of isocyanates.
Scheme 20: a) Unsuccessful coupling of p-toluenesulfonamide and DCC in solution and by neat/LAG ball milling. ...
Scheme 21: a) Expansion of the saccharin ring by mechanochemical insertion of carbodiimides. b) Insertion of D...
Scheme 22: Synthesis of highly basic biguanides by ball milling.
Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70
Graphical Abstract
Figure 1: Selected piperazine-containing small-molecule pharmaceuticals.
Figure 2: Strategies for the synthesis of carbon-substituted piperazines.
Figure 3: The first α-lithiation of N-Boc-protected piperazines by van Maarseveen et al. in 2005 [37].
Figure 4: α-Lithiation of N-Boc-N’-tert-butyl piperazines by Coldham et al. in 2010 [38].
Figure 5: Diamine-free α-lithiation of N-Boc-piperazines by O’Brien, Campos, et al. in 2010 [40].
Figure 6: The first enantioselective α-lithiation of N-Boc-piperazines by McDermott et al. in 2008 [41].
Figure 7: Dynamic thermodynamic resolution of lithiated of N-Boc-piperazines by Coldham et al. in 2010 [38].
Figure 8: Enantioselective α-lithiation of N-Boc-N’-alkylpiperazines by O’Brien et al. in 2013 and 2016 [42,43].
Figure 9: Asymmetric α-functionalization of N-Boc-piperazines with Ph2CO by O’Brien et al. in 2016 [43].
Figure 10: A “chiral auxiliary” strategy toward enantiopure α-functionalized piperazines by O’Brien et al. 201...
Figure 11: Installation of methyl group at the α-position of piperazines by O’Brien et al. 2016 [43].
Figure 12: α-Lithiation trapping of C-substituted N-Boc-piperazines by O’Brien et al. 2016 [43].
Figure 13: Rh-catalyzed reactions of N-(2-pyridinyl)piperazines by Murai et al. in 1997 [52].
Figure 14: Ta-catalyzed hydroaminoalkylation of piperazines by Schafer et al. in 2013 [55].
Figure 15: Photoredox catalysis for α-C–H functionalization of piperazines by MacMillan et al. in 2011 and 201...
Figure 16: Copper-catalyzed aerobic C–H oxidation of piperazines by Touré, Sames, et al. in 2013 [67].
Figure 17: Free radical approach by Undheim et al. in 1994 [68].
Figure 18: Anodic oxidation approach by Nyberg et al. in 1976 [70].
Beilstein J. Org. Chem. 2015, 11, 1509–1513, doi:10.3762/bjoc.11.164
Graphical Abstract
Figure 1: The structure of mianserin 1 and epinastine 2.
Scheme 1: Enantioselective synthesis of (S)-(+)-mianserin.
Figure 2: Catalysts used in ATH.
Figure 3: The ORTEP diagram for X-ray analysis of compound (S)-7.
Scheme 2: Enantioselective synthesis of (S)-(+)-epinastine.
Beilstein J. Org. Chem. 2013, 9, 313–322, doi:10.3762/bjoc.9.36
Graphical Abstract
Scheme 1: Intermolecular carbolithiation.
Scheme 2: Carbolithiation of cinnamyl and dienyl derivatives.
Scheme 3: Carbolithiation of cinnamyl alcohol.
Scheme 4: Carbolithiation of styrene derivatives.
Scheme 5: Carbolithiation of α-aryl O-alkenyl carbamates.
Scheme 6: Carbolithiation-rearrangement of N-alkenyl-N-arylureas.
Scheme 7: Carbolithiation of N,N-dimethylaminofulvene.
Scheme 8: Carbolithiation of enynes.
Scheme 9: Intramolecular carbolithiation.
Scheme 10: Carbolithiation of 5-alkenylcarbamates.
Scheme 11: Carbolithiation of cinnamylpiperidines.
Scheme 12: Carbolithiation of alkenylpyrrolidines.
Scheme 13: Enantioselective carbolithiation of N-allyl-2-bromoanilines.
Scheme 14: Effect of the ligand in the carbolithiation reaction.
Scheme 15: Effect of the alkene substitution in the carbolithiation reaction.
Scheme 16: Effect of the ring substitution in the carbolithiation reaction.
Scheme 17: Enantioselective carbolithiation of allyl aryl ethers.
Scheme 18: Formation of six-membered rings: pyrroloisoquinolines.
Scheme 19: Formation of six-membered rings: tetrahydroquinolines.
Beilstein J. Org. Chem. 2013, 9, 155–165, doi:10.3762/bjoc.9.18
Graphical Abstract
Scheme 1: Activation of amine-bonded Michael acceptors by protonation versus Lewis acid interaction.
Scheme 2: Synthesis of 4-hydroxycoumarin derivatives by Michael addition [19-27].
Scheme 3: Precatalysts 5–8 and synthesis from chiral 1,2-diamines and 2-sulfobenzoic anhydrides.
Figure 1: X-ray crystallographic structure of 5. The conformation of the 2-sulfobenzoic moiety is fixed by hy...
Figure 2: Michael acceptors employed as substrates in the nucleophilic addition of 4-hydroxycoumarin (1).
Scheme 4: Computationally analyzed pathways A (C-protonation), and B (N-protonation), arising from the additi...
Scheme 5: Computed energy profile for reaction path A (C-protonation) and B (N-protonation) corresponding to ...
Figure 3: Enantio-determining transition states arising from the addition of 4-hydroxycoumarin to cyclohexeno...
Figure 4: The competing enantio-determining transition structures TS-14a and TS-14g. The reason for the desta...
Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148
Graphical Abstract
Figure 1: Modular synthesis of bis(diarylphosphino)-, bis(dialkylphosphino)- and dialkyl(diaryl)phosphinobiph...
Figure 2: ARYNE coupling.
Scheme 1: Functionalization of 2,2',6-tribromobiphenyl (1a) by regioselective bromine–lithium exchange.
Scheme 2: Functionalization of 2,2'-dibromobiphenyls (1b–e) by regioselective bromine–lithium exchange.
Figure 3: General access to biaryl mono- and diphosphine ligands; (Cy = cyclohexyl).
Scheme 3: Synthesis of monophosphines 3; (Cy = cyclohexyl).
Figure 4: Molecular structure of compound 3a (crystallized from ethyl acetate/hexane) [74].
Scheme 4: Preparation of mixed dialkyl(diaryl)phosphinobiphenyls 5 via successive bromine–lithium exchange.
Scheme 5: Stepwise bromine–lithium exchange on 1c.
Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32
Graphical Abstract
Figure 1: Biologically important amines and quaternary ammonium salts: histamine (1), dopamine (2) and acetyl...
Figure 2: Crown ether 18-crown-6.
Figure 3: Conformations of 18-crown-6 (4) in solvents of different polarity.
Figure 4: Binding topologies of the ammonium ion depending on the crown ring size.
Figure 5: A “pseudorotaxane” structure consisting of 24-crown-8 and a secondary ammonium ion (5); R = Ph.
Figure 6: Typical examples of azacrown ethers, cryptands and related aza macrocycles.
Figure 7: Binding of ammonium to azacrown ethers and cryptands [111-113].
Figure 8: A 19-crown-6-ether with decalino blocking groups (11) and a thiazole-dibenzo-18-crown-6-ether (12).
Figure 9: 1,3-Bis(6-oxopyridazin-1-yl)propane derivatives 13 and 14 by Campayo et al.
Figure 10: Fluorescent azacrown-PET-sensors based on coumarin.
Figure 11: Two different pyridino-cryptands (17 and 18) compared to a pyridino-crown (19); chiral ammonium ion...
Figure 12: Pyridino-18-crown-6 ligand (21), a similar acridino-18-crown-6 ligand (22) and a structurally relat...
Figure 13: Ciral pyridine-azacrown ether receptors 24.
Figure 14: Chiral 15-crown-5 receptors 26 and an analogue 18-crown-6 ligand 27 derived from amino alcohols.
Figure 15: C2-symmetric chiral 18-crown-6 amino alcohol derivatives 28 and related macrocycles.
Figure 16: Macrocycles with diamide-diester groups (30).
Figure 17: C2-symmetric chiral aza-18-crown-6 ethers (31) with phenethylamine residues.
Figure 18: Chiral C-pivot p-methoxy-phenoxy-lariat ethers.
Figure 19: Chiral lariat crown ether 34.
Figure 20: Sucrose-based chiral crown ether receptors 36.
Figure 21: Permethylated fructooligosaccharide 37 showing induced-fit chiral recognition.
Figure 22: Biphenanthryl-18-crown-6 derivative 38.
Figure 23: Chiral lariat crown ethers derived from binol by Fuji et al.
Figure 24: Chiral phenolic crown ether 41 with “aryl chiral barriers” and guest amines.
Figure 25: Chiral bis-crown receptor 43 with a meso-ternaphthalene backbone.
Figure 26: Chromogenic pH-dependent bis-crown chemosensor 44 for diamines.
Figure 27: Triamine guests for binding to receptor 44.
Figure 28: Chiral bis-crown phenolphthalein chemosensors 46.
Figure 29: Crown ether amino acid 47.
Figure 30: Luminescent receptor 48 for bis-alkylammonium guests.
Figure 31: Luminescent CEAA (49a), a bis-CEAA receptor for amino acids (49b) and the structure of lysine bindi...
Figure 32: Luminescent CEAA tripeptide for binding small peptides.
Figure 33: Bis crown ether 51a self assembles co-operatively with C60-ammonium ion 51b.
Figure 34: Triptycene-based macrotricyclic dibenzo-[24]-crown-8 ether host 52 and guests.
Figure 35: Copper imido diacetic acid azacrown receptor 53a and the suggested His-Lys binding motif; a copper ...
Figure 36: Urea (54) and thiourea (55) benzo crown receptor for transport and extraction of amino acids.
Figure 37: Crown pyryliums ion receptors 56 for amino acids.
Figure 38: Ditopic sulfonamide bridged crown ether receptor 57.
Figure 39: Luminescent peptide receptor 58.
Figure 40: Luminescent receptor 59 for the detection of D-glucosamine hydrochloride in water/ethanol and lumin...
Figure 41: Guanidinium azacrown receptor 61 for simple amino acids and ditopic receptor 62 with crown ether an...
Figure 42: Chiral bicyclic guanidinium azacrown receptor 63 and similar receptor 64 for the enantioselective t...
Figure 43: Receptors for zwitterionic species based on luminescent CEAAs.
Figure 44: 1,10-Azacrown ethers with sugar podand arms and the anticancer agent busulfan.
Figure 45: Benzo-18-crown-6 modified β-cyclodextrin 69 and β-cyclodextrin functionalized with diaza-18-crown-6...
Figure 46: Receptors for colorimetric detection of primary and secondary ammonium ions.
Figure 47: Porphyrine-crown-receptors 72.
Figure 48: Porphyrin-crown ether conjugate 73 and fullerene-ammonium ion guest 74.
Figure 49: Calix[4]arene (75a), homooxocalix[4]arene (75b) and resorcin[4]arene (75c) compared (R = H, alkyl c...
Figure 50: Calix[4]arene and ammonium ion guest (R = H, alkyl, OAcyl etc.), possible binding sites; A: co-ordi...
Figure 51: Typical guests for studies with calixarenes and related molecules.
Figure 52: Lower rim modified p-tert-butylcalix[5]arenes 82.
Figure 53: The first example of a water soluble calixarene.
Figure 54: Sulfonated water soluble calix[n]arenes that bind ammonium ions.
Figure 55: Displacement assay for acetylcholine (3) with a sulfonato-calix[6]arene (84b).
Figure 56: Amino acid inclusion in p-sulfonatocalix[4]arene (84a).
Figure 57: Calixarene receptor family 86 with upper and lower rim functionalization.
Figure 58: Calix[6]arenes 87 with one carboxylic acid functionality.
Figure 59: Sulfonated calix[n]arenes with mono-substitution at the lower rim systematically studied on their r...
Figure 60: Cyclotetrachromotropylene host (91) and its binding to lysine (81c).
Figure 61: Calixarenes 92 and 93 with phosphonic acids groups.
Figure 62: Calix[4]arene tetraphosphonic acid (94a) and a double bridged analogue (94b).
Figure 63: Calix[4]arene tetraphosphonic acid ester (92c) for surface recognition experiments.
Figure 64: Calixarene receptors 95 with α-aminophosphonate groups.
Figure 65: A bridged homocalix[3]arene 95 and a distally bridged homocalix[4]crown 96.
Figure 66: Homocalix[3]arene ammonium ion receptor 97a and the Reichardt’s dye (97b) for colorimetric assays.
Figure 67: Chromogenic diazo-bridged calix[4]arene 98.
Figure 68: Calixarene receptor 99 by Huang et al.
Figure 69: Calixarenes 100 reported by Parisi et al.
Figure 70: Guest molecules for inclusion in calixarenes 100: DAP × 2 HCl (101a), APA (101b) and Lys-OMe × 2 HC...
Figure 71: Different N-linked peptido-calixarenes open and with glycol chain bridges.
Figure 72: (S)-1,1′-Bi-2-naphthol calixarene derivative 104 published by Kubo et al.
Figure 73: A chiral ammonium-ion receptor 105 based on the calix[4]arene skeleton.
Figure 74: R-/S-phenylalaninol functionalized calix[6]arenes 106a and 106b.
Figure 75: Capped homocalix[3]arene ammonium ion receptor 107.
Figure 76: Two C3 symmetric capped calix[6]arenes 108 and 109.
Figure 77: Phosphorous-containing rigidified calix[6]arene 110.
Figure 78: Calix[6]azacryptand 111.
Figure 79: Further substituted calix[6]azacryptands 112.
Figure 80: Resorcin[4]arene (75c) and the cavitands (113).
Figure 81: Tetrasulfonatomethylcalix[4]resorcinarene (114).
Figure 82: Resorcin[4]arenes (115a/b) and pyrogallo[4]arenes (115c, 116).
Figure 83: Displacement assay for acetylcholine (3) with tetracyanoresorcin[4]arene (117).
Figure 84: Tetramethoxy resorcinarene mono-crown-5 (118).
Figure 85: Components of a resorcinarene based displacement assay for ammonium ions.
Figure 86: Chiral basket resorcin[4]arenas 121.
Figure 87: Resorcinarenes with deeper cavitand structure (122).
Figure 88: Resorcinarene with partially open deeper cavitand structure (123).
Figure 89: Water-stabilized deep cavitands with partially structure (124, 125).
Figure 90: Charged cavitands 126 for tetralkylammonium ions.
Figure 91: Ditopic calix[4]arene receptor 127 capped with glycol chains.
Figure 92: A calix[5]arene dimer for diammonium salt recognition.
Figure 93: Calixarene parts 92c and 129 for the formation molecular capsules.
Figure 94: Encapsulation of a quaternary ammonium cation by two resorcin[4]arene molecules (NMe4+@[75c]2 × Cl−...
Figure 95: Encapsulation of a quaternary ammonium cation by six resorcin[4]arene molecules (NMe3D+@[130]6 × Cl−...
Figure 96: Structure and schematic of cucurbit[6]uril (CB[6], 131a).
Figure 97: Cyclohexanocucurbit[6]uril (CB′[6], 132) and the guest molecule spermine (133).
Figure 98: α,α,δ,δ-Tetramethylcucurbit[6]uril (134).
Figure 99: Structure of the cucurbituril-phthalhydrazide analogue 135.
Figure 100: Organic cavities for the displacement assay for amine differentiation.
Figure 101: Displacement assay methodology for diammonium- and related guests involving cucurbiturils and some ...
Figure 102: Nor-seco-Cucurbituril (±)-bis-ns-CB[6] (140) and guest molecules.
Figure 103: The cucurbit[6]uril based complexes 141 for chiral discrimination.
Figure 104: Cucurbit[7]uril (131c) and its ferrocene guests (142) opposed.
Figure 105: Cucurbit[7]uril (131c) guest inclusion and representative guests.
Figure 106: Cucurbit[7]uril (131c) binding to succinylcholine (145) and different bis-ammonium and bis-phosphon...
Figure 107: Paraquat-cucurbit[8]uril complex 149.
Figure 108: Gluconuril-based ammonium receptors 150.
Figure 109: Examples of clefts (151a), tweezers (151b, 151c, 151d) and clips (151e).
Figure 110: Kemp’s triacid (152a), on example of Rebek’s receptors (152b) and guests.
Figure 111: Amino acid receptor (154) by Rebek et al.
Figure 112: Hexagonal lattice designed hosts by Bell et al.
Figure 113: Bell’s amidinium receptor (156) and the amidinium ion (157).
Figure 114: Aromatic phosphonic acids.
Figure 115: Xylene phosphonates 159 and 160a/b for recognition of amines and amino alcohols.
Figure 116: Bisphosphonate recognition motif 161 for a colorimetric assay with alizarin complexone (163) for ca...
Figure 117: Bisphosphonate/phosphate clip 164 and bisphosphonate cleft 165.
Figure 118: N-Methylpyrazine 166a, N-methylnicotinamide iodide (166b) and NAD+ (166c).
Figure 119: Bisphosphate cavitands.
Figure 120: Bisphosphonate 167 of Schrader and Finocchiaro.
Figure 121: Tweezer 168 for noradrenaline (80b).
Figure 122: Different tripods and heparin (170).
Figure 123: Squaramide based receptors 172.
Figure 124: Cage like NH4+ receptor 173 of Kim et al.
Figure 125: Ammonium receptors 174 of Chin et al.
Figure 126: 2-Oxazolin-based ammonium receptors 175a–d and 176 by Ahn et al.
Figure 127: Racemic guest molecules 177.
Figure 128: Tripods based on a imidazole containing macrocycle (178) and the guest molecules employed in the st...
Figure 129: Ammonium ion receptor 180.
Figure 130: Tetraoxa[3.3.3.3]paracyclophanes 181 and a cyclophanic tetraester (182).
Figure 131: Peptidic bridged paraquat-cyclophane.
Figure 132: Shape-selective noradrenaline host.
Figure 133: Receptor 185 for binding of noradrenaline on surface layers from Schrader et al.
Figure 134: Tetraphosphonate receptor for binding of noradrenaline.
Figure 135: Tetraphosphonate 187 of Schrader and Finocchiaro.
Figure 136: Zinc-Porphyrin ammonium-ion receptors 188 and 189 of Mizutani et al.
Figure 137: Zinc porphyrin receptor 190.
Figure 138: Zinc porphyrin receptors 191 capable of amino acid binding.
Figure 139: Zinc-porphyrins with amino acid side chains for stereoinduction.
Figure 140: Bis-zinc-bis-porphyrin based on Tröger’s base 193.
Figure 141: BINAP-zinc-prophyrin derivative 194 and it’s guests.
Figure 142: Bisaryl-linked-zinc-porphyrin receptors.
Figure 143: Bis-zinc-porphyrin 199 for diamine recognition and guests.
Figure 144: Bis-zinc-porphyrin crown ether 201.
Figure 145: Bis-zinc-porphyrin 202 for stereodiscrimination (L = large substituent; S = small substituent).
Figure 146: Bis-zinc-porphyrin[3]rotaxane and its copper complex and guests.
Figure 147: Dien-bipyridyl ligand 206 for co-ordination of two metal atoms.
Figure 148: The ligand and corresponding tetradentate co-complex 207 serving as enantioselective receptor for a...
Figure 149: Bis(oxazoline)–copper(II) complex 208 for the recognition of amino acids in aqueous solution.
Figure 150: Zinc-salen-complexes 209 for the recognition tertiary amines.
Figure 151: Bis(oxazoline)–copper(II) 211 for the recognition of amino acids in aqueous solution.
Figure 152: Zn(II)-complex of a C2 terpyridine crown ether.
Figure 153: Displacement assay and receptor for aspartate over glutamate.
Figure 154: Chiral complex 214 for a colorimetric displacement assay for amino acids.
Figure 155: Metal complex receptor 215 with tripeptide side arms.
Figure 156: A sandwich complex 216 and its displaceable dye 217.
Figure 157: Lanthanide complexes 218–220 for amino acid recognition.
Figure 158: Nonactin (221), valinomycin (222) and vancomycin (223).
Figure 159: Monesin (224a) and a chiral analogue for enantiodiscrimination of ammonium guests (224b).
Figure 160: Chiral podands (226) compared to pentaglyme-dimethylether (225) and 18-crown-6 (4).
Figure 161: Lasalocid A (228).
Figure 162: Lasalocid derivatives (230) of Sessler et al.
Figure 163: The Coporphyrin I tetraanion (231).
Figure 164: Linear and cyclic peptides for ammonium ion recognition.
Figure 165: Cyclic and bicyclic depsipeptides for ammonium ion recognition.
Figure 166: α-Cyclodextrin (136a) and novocaine (236).
Figure 167: Helical diol receptor 237 by Reetz and Sostmann.
Figure 168: Ammonium binding spherand by Cram et al. (238a) and the cyclic[6]metaphenylacetylene 238b in compar...
Figure 169: Receptor for peptide backbone and ammonium binding (239).
Figure 170: Anion sensor principle with 3-hydroxy-2-naphthanilide of Jiang et al.
Figure 171: 7-bromo-3-hydroxy-N-(2-hydroxyphenyl)naphthalene 2-carboxamide (241) and its amine binding.
Figure 172: Naturally occurring catechins with affinity to quaternary ammonium ions.
Figure 173: Spiropyran (244) and merocyanine form (244a) of the amino acid receptors of Fuji et al.
Figure 174: Coumarin aldehyde (245) and its iminium species with amino acid bound (245a) by Glass et al.
Figure 175: Coumarin aldehyde appended with boronic acid.
Figure 176: Quinolone aldehyde dimers by Glass et al.
Figure 177: Chromogenic ammonium ion receptors with trifluoroacetophenone recognition motifs.
Figure 178: Chromogenic ammonium ion receptor with trifluoroacetophenone recognition motif bound on different m...
Beilstein J. Org. Chem. 2008, 4, No. 28, doi:10.3762/bjoc.4.28
Graphical Abstract
Scheme 1: Diels-Alder reaction of anthrones 1 and maleimides 2 catalyzed by chiral Brønsted bases 4–8.
Scheme 2: Protonation states and tautomerism of C2-symmetric bisamidine 8a [6].
Scheme 3: Synthesis of C2-symmetric bisamidines 8b–c and ent-8d.
Figure 1: Kinetic measurements of 1a with 2a catalyzed by 5 mol% of 8a·H+·TFPB- (black line) and 1 mol% 8a (f...
Figure 2: Molecular structure of 3m (C: black; N: blue; O: red; Cl: green; hydrogen atoms are omitted for the...
Scheme 4: Proposed mechanism of the Diels-Alder reaction.