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Search for "cyclophane" in Full Text gives 33 result(s) in Beilstein Journal of Organic Chemistry.
Use of mixed Li/K metal TMP amide (LiNK chemistry) for the synthesis of [2.2]metacyclophanes
- Marco Blangetti,
- Patricia Fleming and
- Donal F. O'Shea
Beilstein J. Org. Chem. 2011, 7, 1249–1254, doi:10.3762/bjoc.7.145
- [2.2]cyclophane structures and have extensively studied their unusual physical and chemical properties induced by the close spatial proximity of their aryl rings [8]. Undoubtedly the most studied of the series (ortho, meta and para) are the [2.2]paracyclophanes, which have seen a recent resurgence of
- synthesis required identical conditions to the first to provide the di-benzylic metalated derivatives 7 (Table 2). We anticipated that an intramolecular ring closing by oxidative coupling would provide the desired cyclophane product in addition to open chain oligomers or larger ring systems. Substrates 6a–e
- were treated with two equivalents of BuLi/KOt-Bu/TMP(H) to generate the corresponding dianions 7a–e, which upon oxidative coupling gave the corresponding metacyclophanes 8a–e. This provided unsubstituted cyclophane 8a in 40% yield and 5,13-disubstituted derivatives 8b–d, containing CH3, OCH3 and N(CH3
Graphical Abstract
Scheme 1: Selective benzylic metalation with LiNK conditions. DG = directing group.
Scheme 2: Iterative LiNK/oxidative coupling synthesis of [2.2]metacyclophanes.
Figure 1: Xylene substrates.
Figure 2: Metalation selectivity for 4e (arrows indicate potential metalation sites). 2H NMR spectrum in CH2Cl...
Figure 3: Di-metalation selectivity for 6f. 2H NMR spectrum in CH2Cl2. *CD2Cl2.
Figure 4: X-Ray structure of 8c with thermal ellipsoids drawn at 50% probability level.
Intraannular photoreactions in pseudo-geminally substituted [2.2]paracyclophanes
- Henning Hopf,
- Vitaly Raev and
- Peter G. Jones
Beilstein J. Org. Chem. 2011, 7, 658–667, doi:10.3762/bjoc.7.78
- this case the cyclophane moiety is the “order-generating” part of the molecule and the originally flexible, unsaturated chain remain attached to each other by stable C–C-bonds; altogether the process amounts to a stiffening (rigidization) of the molecules 3. In the case of the bis amide 5 (Scheme 2
Graphical Abstract
Scheme 1: [2.2]Paracyclophanes as scaffolds for intraannular photodimerization reactions in solution.
Scheme 2: Stereospecific intramolecular [2+2]photoadditions using [2.2]paracyclophane spacers.
Scheme 3: Different conformations of pseudo-geminal divinyl[2.2]paracyclophane.
Scheme 4: Preparation of tetraene 11.
Scheme 5: Photolysis of tetraene 11.
Figure 1: The molecule of compound 13 in the crystal. Ellipsoids correspond to 30% probability levels.
Scheme 6: Photolysis of trans,trans-dienal 10.
Figure 2: The molecule of compound 15 in the crystal. Ellipsoids correspond to 30% probability levels.
Scheme 7: Cis–trans-isomerizations of the double bonds of the pseudo-geminal cyclophanes 11 and 19.
Scheme 8: Preparation of the vinylcyclopropanes 22–24.
Figure 3: The two independent molecules of compound Z,Z-22 in the crystal. Ellipsoids correspond to 50% proba...
Figure 4: The molecule of compound 23 in the crystal. Ellipsoids correspond to 50% probability levels.
Figure 5: The molecule of compound 24 in the crystal. Ellipsoids correspond to 30% probability levels.
Molecular recognition of organic ammonium ions in solution using synthetic receptors
- Andreas Späth and
- Burkhard König
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...
Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides
- Ana Maria Castilla,
- M. Morgan Conn and
- Pablo Ballester
Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5
- stereoselectivity exhibited by the cyclic receptors, together with the lack of selectivity for the size of the amino acid side chain, encourages us to propose that the geometry of the 1:1 complex is, most likely, exo-cyclic. In other words, the dipeptide is not threaded through the cyclophane skeleton of the
Graphical Abstract
Figure 1: Schematic representation of the design of a host–guest complex based on antiparallel β-sheet geomet...
Figure 2: Molecular structures of the two designed receptors 1 and 2 having different relative orientations o...
Figure 3: CAChe minimized structures for the “endo” complexes formed between receptors 1 (a) and 2 (b) and th...
Scheme 1: Synthesis of tetraprotected bis(alanyl)benzophenones 3 from L-phenylalanine 7.
Scheme 2: Deprotection reactions of bis(alanyl)benzophenone units 3.
Scheme 3: Synthesis of the linear tetrapeptides 15 and 17 as mixtures of diastereoisomers.
Figure 4: a) Molecular structures of the two major diastereoisomers of the cyclic receptors obtained from the...
Figure 5: Reverse-phase HPLC chromatograms of the purified fraction obtained from macrocyclization reactions ...
Figure 6: Variable-temperature 1H NMR experiments of 1 in chloroform-d solution. The proton signals that appe...
Figure 7: Small fraction of the columnar arrangement observed in solid-state packing of receptor 1. Two adjac...
Figure 8: Molecular structures of the guests used in the binding experiments.
Figure 9: Selected region of the variable-concentration 1H NMR spectra acquired using chloroform-d solutions ...
Figure 10: a) Selected region of a series 1H NMR spectra acquired during titration of receptor 2 with n-C6H13-...
Figure 11: CAChe minimized structures for two possible binding geometries, a) exo and b) endo complexes formed...
[3.3]Dithia-bridged cyclophanes featuring a thienothiophene ring: synthesis, structures and conformational analysis
- Sabir H. Mashraqui,
- Yogesh Sanghvikar,
- Shailesh Ghadhigaonkar,
- Sukeerthi Kumar,
- Auke Meetsma and
- Elise Trân Huu Dâu
Beilstein J. Org. Chem. 2009, 5, No. 74, doi:10.3762/bjoc.5.74
- ], nonlinear optics [22] and axially chiral systems [23]. We have also recently incorporated a thienothiophene ring within the cyclophane framework via its 3,4-positions, leading to the synthesis of meta type 1,3-dithia-bridged thienothiophenophanes 1–2 [24]. Cyclophanes 1–2 (Figure 1) have been found to
- conditions and under N2 atmosphere. The crude solid obtained on work-up was purified by column chromatography on SiO2 affording the desired meta dithia[3.3]cyclophane 7, m.p. 247–250 °C as a colorless solid in 57% yield. Likewise, the para dithia-bridged thienothiophenophanes 9 and 11 were prepared by
- conformational analysis of thienothiophenophanes 7, 9 and 11 The 1H NMR (300 MHz) spectrum of dithia-cyclophane 7 revealed two AB spin systems (4H each) in the range of δ 3.21–4.30 due to the geminal couplings of the bridged –CH2- protons. A singlet centered at δ 2.31 accounted for the C3/C4 methyl groups. The
Graphical Abstract
Figure 1: Conformationally flexible 3, 4-bridged dithia-thienothiophenophanes.
Scheme 1: Synthetic scheme for compounds 7, 9 and 11.
Figure 2: ORTEP plot of the crystal structure of 11. Important parameters: Bond length (Å) : C8–C9 = 1.492, C...
Scheme 2: Computed three most stable conformations of 11 and their calculated energies.
Reversible intramolecular photocycloaddition of a bis(9-anthrylbutadienyl)paracyclophane – an inverse photochromic system. (Photoactive cyclophanes 5)
- Henning Hopf,
- Christian Beck,
- Jean-Pierre Desvergne,
- Henri Bouas-Laurent,
- Peter G. Jones and
- Ludger Ernst
Beilstein J. Org. Chem. 2009, 5, No. 20, doi:10.3762/bjoc.5.20
- the cyclophane acting as a convenient scaffold, as demonstrated previously [18][19]. To avoid steric crowding and excessive distance between the chromophores, it seemed reasonable to select the rigid all-trans butadienyl tether as represented in compound 2 (see Figure 3). The synthesis, molecular
- % overall yield as described previously [19]. Therefore, the overall yield of 2 from the parent cyclophane was found tobe 35% on the gram scale. The Wittig reaction provides a mixture of cis and trans isomers, but the pure all-trans isomer was isolated by crystallization as orange crystals (see Experimental
- naphthalenes [21], but because the disubstituted cyclophane also absorbs in that region [22], it is difficult to get more precise information. The 1H NMR (Figure 10 and Supporting Information p S2) and the 13C NMR spectra (52 distinct signals are observed, see Experimental) point to the absence of symmetry in
Graphical Abstract
Figure 1: Schematic representation of a photochromic system. The reverse reaction can be a photochemical or t...
Figure 2: Photochromic reaction of pseudo-gem disubstituted tetraene [2.2]cyclophane 1 in acetonitrile, conc....
Figure 3: Molecular structure of 4,13-bis[(1E,3E)-4-(9-anthracenyl)-buta-1,3-dienyl][2.2]paracyclophane (2).
Scheme 1: Preparation of 2 (last step), using the Wittig reaction. The preparation of 3 has been described in...
Figure 4: Molecular structure of 2 in the crystal. Radii are arbitrary; only selected H atoms are shown.
Figure 5: Projection of the molecular structure of 2 exhibiting the closest internuclear distances (distances...
Figure 6: Electronic absorption spectra of 2 (conc. ca 10−4 M) in MCH (full line) and CH3CN (dotted line) at ...
Figure 7: Irradiation of 2 (2.6 × 10−5 M) in CH3CN at 400 nm at 20 °C. The spectra were recorded at various t...
Figure 8: Irradiation at 306 nm of the photoproduct 4 obtained at 400 nm in the same setup; the spectra were ...
Figure 9: Reversibility of the formation of the photoproduct 4 at 400 nm (40 min) and photodissociation of 4 ...
Figure 10: 1H NMR spectra (400 MHz, CDCl3). A: Compound 2, B: Compound 4.
Figure 11: Proposed structure of 4 (1,4 : 2′,3′-cycloadduct).
Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives
- Gareth J. Rowlands and
- Richard J. Seacome
Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9
- derivatives [15]. Chiral sulfur [2.2]paracyclophane derivatives are beginning to attract attention due to the great potential such compounds exhibit [16][17][18]. Non-cyclophane-based thiophenol derivatives have been employed in the nucleophilic addition of thioacetals to suitable electrophiles [19][20
Graphical Abstract
Figure 1: [2.2]Paracyclophane (1) showing standard numbering and [2.2]paracyclophane-4-thiol (2).
Scheme 1: Conversion of [2.2]paracyclophane to enantiomerically enriched [2.2]paracyclophane-4-thiol.
Scheme 2: Synthesis of [2.2](4,7)benzo[d]thiazoloparacyclophane (Rp)-10.
Molecular recognition. 1. Crystal structures of hexaazamacrocyclic amines containing p-xylylene spacers and their adducts with acids
- Teresa Borowiak,
- Grzegorz Dutkiewicz,
- Maciej Kubicki,
- Marek Pietraszkiewicz,
- Agnieszka Gil and
- Rainer Mattes
Beilstein J. Org. Chem. 2005, 1, No. 16, doi:10.1186/1860-5397-1-16
- Institute of Inorganic and Analytical Chemistry, University Muenster Corrensstrasse 36, 48149 Muenster, Germany 10.1186/1860-5397-1-16 Abstract The macrocyclic amine, 1,5,9,18,22,26-hexaaza [11.11]-p-cyclophane (1) contains two dipropylenetriamine units which make the molecule highly basic. Owing to this
- efficiency in activation of substrates. This leads to numerous properties as magnetic, electronic or catalytic. [1][3][4][5] In our previous paper we described the supramolecular structures of 1,5,9,18,22,26-hexaaza [11.11]-p-cyclophane (hereafter 1, Scheme 1) complexes with o-nitrophenol and hydrochloric
- secondary amine with a lesser effect produced by the spacer. As the number of methylene units increases, the basicity of the macrocyclic ligands also increases because the amino-groups lie further apart from one another [2] in comparison with 1,4,7,16,19,22-hexaaza [9.9]-p-cyclophane (hereafter 2, Scheme 1
Graphical Abstract
Scheme 1: Formulas of macrocyclic amines, 1: 1,5,9,18,22,26-hexaaza [11.11]-p-cyclophane and 2: 1,4,7,16,19,2...
Figure 1: The ionic synthon of 1-FUM built from one macrocyclic hexa-protonated cation and six fumaric anions...
Figure 2: The structure of one sheet in 1-FUM – a projection perpendicular to the phenyl ring planes. Tapes o...
Figure 3: The arrangement of two sheets (after rotation by 90°). The height of one sheet corresponds to the h...
Figure 4: The molecular conformation of 1-N-Me, atom labeling scheme indicated. Displacement parameters are d...
Figure 5: The unit cell of 1-N-Me, stacks of molecules are indicated.
