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Search for "amino alcohols" in Full Text gives 84 result(s) in Beilstein Journal of Organic Chemistry.
Metathesis access to monocyclic iminocyclitol-based therapeutic agents
- Ileana Dragutan,
- Valerian Dragutan,
- Carmen Mitan,
- Hermanus C.M. Vosloo,
- Lionel Delaude and
- Albert Demonceau
Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81
- the 6-membered N-heterocycle in 133. Protection of the amino alcohols trans-132 and cis-132, as the corresponding trans and cis oxazolidinones, afforded a mixture of diastereomers that were not separable on silica gel. After effecting RCM (2nd-generation Grubbs catalyst 5, 5 mol %) on this mixture
Graphical Abstract
Scheme 1: Well-defined Mo- and Ru-alkylidene metathesis catalysts.
Scheme 2: Representative pyrrolidine-based iminocyclitols.
Scheme 3: Synthesis of (±)-(2R*,3R*,4S*)-2-hydroxymethylpyrrolidin-3,4-diol (18), (±)-2-hydroxymethylpyrrolid...
Scheme 4: Synthesis of enantiopure iminocyclitol (−)-(2S,3R,4S,5S)-2,5-dihydroxymethylpyrrolidin-3,4-diol (23...
Scheme 5: Synthesis of 1,4-dideoxy-1,4-imino-D-allitol (29) and formal synthesis of (2S,3R,4S)-3,4-dihydroxyp...
Scheme 6: Synthesis of iminocyclitols 35 and 36.
Scheme 7: Total synthesis of iminocyclitols 40 and 44.
Scheme 8: Synthesis of 2,5-dideoxy-2,5-imino-D-mannitol [(+)-DMDP] (49) and (−)-bulgecinine (50).
Scheme 9: Synthesis of (+)-broussonetine G (53).
Scheme 10: Structural features of broussonetines 54.
Scheme 11: Synthesis of broussonetines by cross-metathesis.
Scheme 12: Representative piperidine-based iminocyclitols.
Scheme 13: Total synthesis of 1-deoxynojirimycin (62) and 1-deoxyaltronojirimycin (65).
Scheme 14: Synthesis by RCM of 1-deoxymannonojirimycin (63) and 1-deoxyallonojirimycin (66).
Scheme 15: Total synthesis of (+)-1-deoxynojirimycin (62).
Scheme 16: Synthesis of ent-1,6-dideoxynojirimycin (83) and 5-amino-1,5,6-trideoxyaltrose (84).
Scheme 17: Synthesis of 1-deoxygalactonojirimycin (64), 1-deoxygulonojirimycin (91) and 1-deoxyidonojirimycin (...
Scheme 18: Synthesis of L-1-deoxyaltronojirimycin (96).
Scheme 19: Synthesis of 1-deoxymannonojirimycin (63) and 1-deoxyaltronojirimycin (65).
Scheme 20: Synthesis of 5-des(hydroxymethyl)-1-deoxymannonojirimycin (111) and 5-des(hydroxymethyl)-1-deoxynoj...
Scheme 21: Synthesis of D-1-deoxygulonojirimycin (91) and L-1-deoxyallonojirimycin (122).
Scheme 22: Total synthesis of fagomine (129), 3-epi-fagomine (126) and 3,4-di-epi-fagomine (130).
Scheme 23: Total synthesis of (+)-adenophorine (135).
Scheme 24: Total synthesis of (+)-5-deoxyadenophorine (138) and analogues 142–145.
Scheme 25: Synthesis by RCM of 1,6-dideoxy-1,6-iminoheptitols 148 and 149.
Scheme 26: Synthesis by RCM of oxazolidinyl azacycles 152 and 154.
Scheme 27: Representative azepane-based iminocyclitols.
Scheme 28: Synthesis of hydroxymethyl-1-(4-methylphenylsulfonyl)azepane 3,4,5-triol (169).
Scheme 29: Synthesis by RCM of tetrahydropyridin-3-ol 171 and tetrahydroazepin-3-ol 173.
Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate
- Michael North and
- Marta Omedes-Pujol
Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119
- and β-amino alcohols [2] (Scheme 1). Asymmetric cyanohydrin synthesis can be achieved by the use of a suitable chiral catalyst, and a wide range of catalysts have been found to catalyse this reaction including enzymes [3][4], organocatalysts [5][6] and metal-based catalysts [1]. All of the most
Graphical Abstract
Scheme 1: Synthesis and transformation of nonracemic silyl-protected cyanohydrins.
Figure 1: Highly active metal(salen) complexes for asymmetric cyanohydrin synthesis.
Scheme 2: Synthesis of cyclic carbonates.
Scheme 3: Synthesis of cyanohydrin trimethylsilyl ethers and acetates.
Scheme 4: Equilibrium between bimetallic and monometallic Ti(salen) complexes.
Figure 2: Second-order kinetics plot for the addition of TMSCN to benzaldehyde at 0 °C catalysed by complex 2...
Figure 3: Plot of k2obs against [2], showing that the reactions are first order with respect to the concentratio...
Figure 4: Eyring plot to determine the activation parameters for catalyst 2 in propylene carbonate. The red a...
Figure 5: 51V NMR spectra of complex 2 recorded at 50 °C. a) Spectrum in CDCl3; b) spectrum in CDCl3 with 500...
Figure 6: Structures consistent with the 51V NMR spectra.
Figure 7: Bimetallic aluminium(salen) complex for asymmetric cyanohydrin synthesis.
Figure 8: Rate determining transition states for asymmetric cyanohydrin synthesis: a) when Lewis base catalys...
Figure 9: Hammett correlations with catalyst 2 at 0 °C. Data in red are obtained in dichloromethane [52], whilst ...
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
- bonding toward the R-enantiomer of phenylalanine methyl ester hydrochloride with KR/KS of 6.87 in CDCl3 with 0.25% CD3OD. The binding constants were far lower as in the former examples. Related macrocycles 30 with diamide-diester groups derived from dimethyloxalate and amino alcohols (Figure 16) also
- conditions for chiral separation of amines and amino alcohols [180]. The azophenolic crown ether was a versatile and a highly enantioselective host for their chiral separation by reactive extraction. Transport from a basic aqueous solution of the racemic mixture in CH2Cl2 and toluene was followed by UV–vis
- )-46b showed an even more intensive color change induced by a wide range of (S)-α-amino alcohols compared to the corresponding (R)-α-amino alcohols. The function, mechanisms and applicability of phenolphthalein crown systems have been recently summarized by Tsubaki [186]. Ditopic receptors can consist
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...
Concise methods for the synthesis of chiral polyoxazolines and their application in asymmetric hydrosilylation
- Wei Jie Li,
- Zun Le Xu and
- Sheng Xiang Qiu
Beilstein J. Org. Chem. 2010, 6, No. 29, doi:10.3762/bjoc.6.29
- , Sun Yat-Sen University, 135 Xingang West Road, Haizhou District, Guangzhou 510275, China 10.3762/bjoc.6.29 Abstract Seven polyoxazoline ligands were synthesized in high yield in a one-pot reaction by heating polycarboxylic acids or their esters and chiral β-amino alcohols under reflux with
- potential, until now, only a few polyoxazoline ligands have been reported in the literature due to synthetic difficulties. In general, the syntheses of polyoxazolines from polycarboxylic acids or polycarboxylates and chiral amino alcohols are carried out via poly(β-hydroxyamide)s as intermediates, followed
- required for the preparation of polyoxazoline ligands. In the present study, we report the results of heating polycarboxylic acids or their esters with chiral β-amino alcohols under reflux conditions with the simultaneous removal of water or the alcohol produced in the reaction in a one-step process for
Palladium- catalyzed cross coupling reactions of 4-bromo- 6H-1,2-oxazines
- Reinhold Zimmer,
- Elmar Schmidt,
- Michal Andrä,
- Marcel-Antoine Duhs,
- Igor Linder and
- Hans-Ulrich Reissig
Beilstein J. Org. Chem. 2009, 5, No. 44, doi:10.3762/bjoc.5.44
- derivatives constitute a versatile class of N,O heterocycles [1][2][3][4][5][6][7][8][9][10][11][12][13]. Considerable attention has been paid to 6H-1,2-oxazines 1 bearing a C-4,C-5-double bond [14][15][16][17][18], which are useful intermediates in the synthesis of γ-lactams [19], γ-amino acids [20], amino
- alcohols [20], aziridines [21], pyrrolizidines [22], and pyrrolidine derivatives [15][23][24]. In the context of our ongoing exploration of the synthetic potential of these heterocycles we were interested to modify the substitution pattern of the C-4,C-5 double bond of 6H-1,2-oxazines [25][26][27]. Herein
Graphical Abstract
Scheme 1: Brominations of 6H-1,2-oxazines. a) Br2, Et2O, −30 °C, 2 h. b) Et3N, −30 °C to r.t., overnight.
Scheme 2: Chlorinations of 6H-1,2-oxazines. a) Cl2, Et2O, −30 °C. b) Et3N, −30 °C to r.t.
Scheme 3: Suzuki-couplings of 4-bromo-6H-1,2-oxazines. a) ArB(OH)2, Pd(PPh3)4, Na2CO3, toluene, 80 °C, 3 h.
Scheme 4: Sonogashira-couplings of 4-bromo-6H-1,2-oxazines. a) PdCl2(PPh3)2, CuI, Et3N, toluene, r.t., 6–20 h....
Scheme 5: Sonogashira-couplings of 4,5-dibromo-6H-1,2-oxazines. a) PdCl2(PPh3)2, CuI, Et3N, toluene, r.t., 4 ...
Scheme 6: Preparation of trisubstituted pyridine derivatives: a) BF3·OEt2, CH2Cl2, −78 °C to r.t., overnight.
(−)-Complanine, an inflammatory substance of marine fireworm: a synthetic study
- Kazuhiko Nakamura,
- Yu Tachikawa and
- Daisuke Uemura
Beilstein J. Org. Chem. 2009, 5, No. 12, doi:10.3762/bjoc.5.12
- absolute structure of complanine was unambiguously determined by means of synthetic methodology by a “chiral synthon” approach. Related amino alcohols possessing olefins from marine natural resources have been identified [3][4], but synthetic studies of these compounds have not been reported. Results and
Graphical Abstract
Figure 1: Structure of (R)-(−)-complanine.
Figure 2: Marine fireworm Eurythoe complanata (body length 10 cm).
Scheme 1: Total synthesis of complanine. Keys: a) 1. BH3·SMe2 (71%); 2. cat. TsOH, Et2CO (59%); 3. TsCl, pyri...
Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition
- Nikolas Pietrzik,
- Daniel Schmollinger and
- Thomas Ziegler
Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30
- variable spacers (Figure 1). Previously, we have prepared a series of glycosylated asparaginic acid building blocks containing as spacers either simple alkyl chains [1], or amino alcohols [2][3]. Such building blocks have been shown to be well suited for combinatorial solid phase or spot synthesis of
Graphical Abstract
Figure 1: Schematic representation of glycosylated building blocks for the combinatorial synthesis of glycope...
Scheme 1: Synthesis and reaction of compounds 4a and 4a'.
Scheme 2: Preparation of compounds 4a–g.
Flexible synthetic routes to poison- frog alkaloids of the 5,8-disubstituted indolizidine- class I: synthesis of common lactam chiral building blocks and application to the synthesis of (-)-203A, (-)-205A, and (-)-219F
- Naoki Toyooka,
- Dejun Zhou,
- Hideo Nemoto,
- H. Martin Garraffo,
- Thomas F. Spande and
- John W. Daly
Beilstein J. Org. Chem. 2007, 3, No. 29, doi:10.1186/1860-5397-3-29
- then treatment of the resulting deblocked amino alcohols with trimethylaluminum under Weinreb's conditions [21] gave rise to the lactams 1 and 2 in 71% and 68% overall yields, respectively. To demonstrate the utility of the chiral lactam building blocks, we conducted the total synthesis of
Graphical Abstract
Figure 1: Representative examples of 5,8-Disubstituted Indolizidines.
Figure 2: Synthetic Strategies to 5,8-Disubstituted Indolizidines from Chiral Building Blocks (1,2).
Scheme 1: Construction of tri-substituted piperidine ring systems (7, 8).
Figure 3: Stereochemical Course of Key Michael-type Conjugate Addition Reaction of 6.
Scheme 2: Synthesis of common lactam-type chiral building blocks (1, 2).
Scheme 3: Synthesis of (-)-203A and (-)-205A.
Scheme 4: Synthesis of (-)-219F.
Reactions of glycidyl derivatives with ambident nucleophiles; part 2: amino acid derivatives
- Gerald Dyker,
- Andreas Thöne and
- Gerald Henkel
Beilstein J. Org. Chem. 2007, 3, No. 28, doi:10.1186/1860-5397-3-28
- ) no cyclization products were obtained. Finally we succeeded in achieving a cyclization by a two-step procedure: the cobalt-catalyzed addition of electron-rich anilines 6 according to Iqbal [9] let to amino alcohols 7, which then cyclized in basic medium (NaH in DMF or THF), either to give 7-membered
Graphical Abstract
Scheme 1: Planned construction for morpholinones 3 from amino acid and glycidyl derivatives 1 and 2. R1, R3 =...
Scheme 2: Synthesis of pyrrolidinone-fused heterocycles from a glycidyl substituted pyroglutamic acid ester 5...
Figure 1: Structure of oxidation product 10a in the crystal.
Scheme 3: Special product conformers, by-products and intermediates of the transformation of 7.
