Search for "mercury" in Full Text gives 187 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
Graphical Abstract
Figure 1: Bond lengths and bond angles in oxetane at 140 K [2].
Figure 2: Analogy of 3-substituted oxetanes to carbonyl and gem-dimethyl groups [12].
Figure 3: Use of oxetanes in drug design – selected examples.
Figure 4: Examples of oxetane-containing natural products.
Scheme 1: Synthetic strategies towards construction of the oxetane ring.
Scheme 2: Overview of intramolecular Williamson etherification and competing Grob fragmentation.
Scheme 3: Synthesis of spiro-oxetanes via 1,4-C–H insertion and Williamson etherification.
Scheme 4: Use of phenyl vinyl selenone in the synthesis of spirooxindole oxetanes.
Scheme 5: Synthesis of bicyclic 3,5-anhydrofuranoses via double epoxide opening/etherification.
Scheme 6: Preparation of spirooxetanes by cycloisomerisation via MHAT/RPC.
Scheme 7: Oxetane synthesis via alcohol C–H functionalisation.
Scheme 8: Access to oxetanes 38 from α-acetyloxy iodides.
Scheme 9: The kilogram-scale synthesis of oxetane intermediate 41.
Scheme 10: Overview of the intramolecular opening of 3-membered rings.
Scheme 11: Synthesis of 4,7-dioxatricyclo[3.2.1.03,6]octane skeletons.
Scheme 12: Silicon-directed electrophilic cyclisation of homoallylic alcohols.
Scheme 13: Hydrosilylation–iodocyclisation of homopropargylic alcohols.
Scheme 14: Cu-catalysed intramolecular O-vinylation of γ-bromohomoallylic alcohols.
Scheme 15: Cu-catalysed intramolecular cross-coupling of hydroxyvinylstannanes.
Scheme 16: Isomerisation of oxiranyl ethers containing weakly carbanion-stabilising groups.
Scheme 17: Cyclisation of diethyl haloalkoxymalonates.
Scheme 18: Synthesis of oxetanes through a 1,5-HAT/radical recombination sequence.
Scheme 19: General approach to oxetanes via [2 + 2] cycloadditions.
Scheme 20: Synthesis of tricyclic 4:4:4 oxetanes through a photochemical triple cascade reaction.
Scheme 21: Iridium-catalysed Paternò–Büchi reaction between α-ketoesters and simple alkenes.
Scheme 22: Three-step synthesis of spirocyclic oxetanes 83 via Paternò–Büchi reaction, nucleophilic ring openi...
Scheme 23: Enantioselective Paternò–Büchi reaction catalysed by a chiral iridium photocatalyst.
Scheme 24: Synthesis of polysubstituted oxetanes 92 via Cu(II)-mediated formal [2 + 2] cycloadditions.
Scheme 25: Synthesis of alkylideneoxetanes via NHC- and DBU-mediated formal [2 + 2] cycloadditions.
Scheme 26: Use of sulphur-stabilised carbanions in ring expansions.
Scheme 27: Synthesis of α,α-difluoro(arylthio)methyl oxetanes.
Scheme 28: Ring expansion in an industrial synthesis of PF-06878031.
Scheme 29: Ring contraction of triflated 2-hydroxy-γ-lactones.
Scheme 30: Ring contraction in an industrial synthesis of PF-06878031.
Scheme 31: Photochemical ring contraction of 2,5-dihydrofurans by aryldiazoacetic acid esters.
Scheme 32: Synthesis of 3-oxetanones via O-H insertion of carbenes.
Scheme 33: Synthesis of phosphonate oxetanones via gold-mediated alkyne oxidation/O–H insertion.
Scheme 34: Syntheses and common derivatisations of 3-oxetanone.
Scheme 35: SN1 substitution of 3-aryloxetan-3-ols by thiols and alcohols.
Scheme 36: Fe–Ni dual-catalytic olefin hydroarylation towards 3-alkyl-3-(hetero)aryloxetanes.
Scheme 37: Synthesis of 3-aryloxetan-3-carboxylic acids.
Scheme 38: Decarboxylative alkylation of 3-aryloxetan-3-carboxylic acids.
Scheme 39: Synthesis of 3-amino-3-aryloxetanes via photoredox/nickel cross-coupling catalysis.
Scheme 40: Intermolecular cross-selective [2 + 2] photocycloaddition towards spirooxetanes.
Scheme 41: Synthesis of 3-aryl-3-aminooxetanes via defluorosulphonylative coupling.
Scheme 42: Two-step synthesis of amide bioisosteres via benzotriazolyl Mannich adducts 170.
Scheme 43: Functionalisation of oxetanyl trichloroacetimidates 172.
Scheme 44: Synthesis of oxetane-amino esters 176.
Scheme 45: Tandem Friedel–Crafts alkylation/intramolecular ring opening of 3-aryloxetan-3-ols.
Scheme 46: Synthesis of polysubstituted furans and pyrroles.
Scheme 47: Synthesis of oxazolines and bisoxazolines.
Scheme 48: Tandem, one-pot syntheses of various polycyclic heterocycles.
Scheme 49: Synthesis of 1,2-dihydroquinolines via skeletal reorganisation of oxetanes.
Scheme 50: Synthesis of benzoindolines and 2,3-dihydrobenzofurans and their derivatisations.
Scheme 51: Synthesis of polysubstituted 1,4-dioxanes.
Scheme 52: Preparation of various lactones via ring opening of oxetane-carboxylic acids 219.
Scheme 53: Tsuji-Trost allylation/ring opening of 3-aminooxetanes.
Scheme 54: Arylative skeletal rearrangement of 3-vinyloxetan-3-ols to 2,5-dihydrofurans.
Scheme 55: Reductive opening of oxetanes using catalytic Mg–H species.
Scheme 56: Opening of oxetanes by silyl ketene acetals.
Scheme 57: Rhodium-catalysed hydroacylation of oxetanes.
Scheme 58: Generation of radicals from oxetanes mediated by a vitamin B12-derived cobalt catalyst.
Scheme 59: Reductive opening of oxetanes by B–Si frustrated Lewis pairs.
Scheme 60: Zirconocene-mediated reductive opening of oxetanes.
Scheme 61: Enantioselective syntheses of small and medium-size rings using chiral phosphoric acids.
Scheme 62: Asymmetric synthesis of 2,3-dihydrobenzo[b]oxepines catalysed by a chiral scandium complex.
Scheme 63: Enantioselective synthesis of 1,3-bromohydrins under a chiral squaramide catalysis.
Scheme 64: Enantioselective opening of 2-aryl-2-ethynyloxetanes by anilines.
Scheme 65: Ru-catalysed insertion of diazocarbonyls into oxetanes.
Scheme 66: Ring expansion of oxetanes by stabilised carbenes generated under blue light irradiation.
Scheme 67: Expansion of oxetanes via nickel-catalysed insertion of alkynyltrifluoroborates.
Scheme 68: Nickel-catalysed expansion of oxetanes into ε-caprolactones.
Scheme 69: Expansion of oxetanes via cobalt-catalysed carbonyl insertion.
Scheme 70: Gold-catalysed intramolecular 1,1-carboalkoxylation of oxetane-ynamides.
Scheme 71: Expansion of oxetanes by stabilised sulphoxonium ylides.
Scheme 72: Cu-catalysed ring expansion of 2-vinyloxetanes by diazoesters.
Scheme 73: Total synthesis of (+)-oxetin.
Scheme 74: Total synthesis of racemic oxetanocin A.
Scheme 75: Total synthesis of (−)-merrilactone A.
Scheme 76: Total synthesis of (+)-dictyoxetane.
Scheme 77: Total synthesis of ent-dichrocephone B.
Scheme 78: Total synthesis of (−)-mitrephorone A.
Scheme 79: Total synthesis of (−)-taxol.
Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89
Graphical Abstract
Figure 1: Schematic depiction of the α-CD channels containing the polyionic {[K(OH2)6]+[AuBr4]−}n chain insid...
Figure 2: Complexes of α-CD with MAuBr4 salts. Left) Co-precipitation yields from aqueous solutions of α-CD (...
Figure 3: Crystal structures of the complexes of α-CD with KAuCN2 salts, with tubular representation for α-CD...
Figure 4: Solid-state structure of the complex 2β-CD·HAuBr4·DBC. (a) Capped-stick and space-filling represent...
Figure 5: Schematic depiction of the selective removal of AuCl4− and its precipitation as solid gold from e-w...
Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81
Graphical Abstract
Figure 1: Reactivity of enamides and enamide cyclizations.
Scheme 1: Total synthesis of (−)-dihydrolycopodine and (−)-lycopodine.
Scheme 2: Collective total synthesis of fawcettimine-type alkaloids.
Scheme 3: Total syntheses of cephalotaxine and cephalezomine H.
Scheme 4: Collective total syntheses of Cephalotaxus alkaloids.
Scheme 5: Asymmetric tandem cyclization/Pictet–Spengler reaction of tertiary enamides.
Scheme 6: Tandem cyclization/Pictet–Spengler reaction for the synthesis of chiral tetracyclic compounds.
Scheme 7: Total synthesis of (−)-cephalocyclidin A.
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
Graphical Abstract
Scheme 1: List of reactions, experimental conditions and yields studied in this work.
Figure 1: Top: 379 MHz 19F NMR spectrum of 9,10-ANTH(BnF)2 in CDCl3. Bottom: absorption (aerobic, solid line)...
Figure 2: Top: X-ray structure of 9,10-ANTH(BnF)2, thermal ellipsoids 50% probability. Bottom: a view down th...
Figure 3: Absorption spectra of ANTH and 9,10-ANTH(BnF)2 in CH2Cl2 recorded over the period of 53 days in air...
Figure 4: Direct analysis in real time (DART) positive ion mass spectrum of the photoirradiated 9,10-ANTH(BnF)...
Figure 5: The % remaining of ANTH and 9,10-ANTH(BnF)2 dissolved in CDCl3 upon irradiation. Resonances δ = 7.4...
Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37
Graphical Abstract
Figure 1: Structures of a) the unfunctionalized bimane scaffold and b) the two isomers of bimanes with their ...
Figure 2: a) Structures of the bimanes studied and b) the reaction scheme of the [2 + 2] photocycloaddition o...
Figure 3: Synthetic approach to bimanes.
Figure 4: View of the molecular structures in the crystal of the functionalized bimanes studied: a) Cl2B (B),...
Figure 5: View of the molecular structure in the crystal of a) symmetry generated by inversion bimanes Cl2B (...
Figure 6: View of the packing of the unit cells of a) Me2B viewed normal to the c-axis and b) Me4B viewed nor...
Figure 7: UV–vis spectrum of Cl2B after irradiation in DCM.
Figure 8: Proposed mechanism for the topochemical [2 + 2] photocycloaddition of Cl2B.
Beilstein J. Org. Chem. 2025, 21, 340–347, doi:10.3762/bjoc.21.24
Graphical Abstract
Scheme 1: Approaches to the synthesis of naphtho[2,3-b]furan-4,9-diones.
Scheme 2: Approaches to the synthesis of furo[2,3-d]pyrimidin-4(3H)-ones.
Scheme 3: Approaches to the synthesis of furan-containing pyranopyrans and pyranochromenes.
Scheme 4: Reaction of alkyl 3-bromo-3-nitroacrylates 1a,b with 2-hydroxynaphthalene-1,4-dione (2a).
Scheme 5: Reaction of alkyl 3-bromo-3-nitroacrylates 1a,b with 4-hydroxy-7,7-dimethyl-7,8-dihydro-2H-1-benzop...
Scheme 6: Reaction of alkyl 3-bromo-3-nitroacrylates 1a,b with 4-hydroxy-7-methyl-2H,5H-pyrano[4,3-b]pyran-2,...
Scheme 7: Reaction of alkyl 3-bromo-3-nitroacrylates 1a,b with pyrimidine-4,6-diols 2e–g.
Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16
Graphical Abstract
Scheme 1: Photochromic reaction of aza-diarylethene derivatives N1–N4 and I1–I4 investigated in this work.
Figure 1: Absorption spectral changes of (a) N3 and (b) I3 in n-hexane at 253 K for N3 and 203 K for I3: open...
Figure 2: Absorbance decay curves and first-order kinetics profiles for (a,b) N3 and (d,e) I3 in n-hexane at ...
Figure 3: Visualization of the difference between ΔG‡(calcd) and ΔG‡(exp) for N1–N4 and I1–I4 by calculation ...
Scheme 2: Synthetic route to aza-diarylethenes N4 and I1–I4.
Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4
Graphical Abstract
Scheme 1: Brief comparison between the main traditional synthetic routes for the preparation of substituted p...
Figure 1: The β-nitrostyrene analogues used in this work.
Scheme 2: Additional products obtained via this method: nitrobenzene and methyl benzoate are reduced in excel...
Figure 2: Numerous masses (m/z) were detected by ESI-MS at T = 0 upon mixing all the reagents to produce 1b.
Figure 3: Structures of proposed adducts. Their masses, 254.2 and 242.2, respectively, were found at T = 0 by...
Scheme 3: Proposed mechanism for the formation of the hydroxylamine side product b. N-Phenethylhydroxylamine (...
Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152
Graphical Abstract
Figure 1: Steroidal spiro heterocycles with remarkable pharmacological activity.
Scheme 1: Synthesis of the spirooxetanone 2. a) t-BuOK, THF, rt, 16%.
Scheme 2: Synthesis of the 17-spirooxetane derivative 7. a) HC≡C(CH2)2CH2OTBDPS, n-BuLi, THF, BF3·Et2O, −78 °...
Scheme 3: Pd-catalyzed carbonylation of steroidal alkynols to produce α-methylene-β-lactones at C-3 and C-17 ...
Scheme 4: Catalyst-free protocol to obtain functionalized spiro-lactones by an intramolecular C–H insertion. ...
Scheme 5: One-pot procedure from dienamides to spiro-β-lactams. a) 1. Ac2O, DMAP, Et3N, CH2Cl2, 2. malononitr...
Scheme 6: Spiro-γ-lactone 20 afforded from 7α-alkanamidoestrone derivative 17. a) HC≡CCH2OTHP, n-BuLi, THF, –...
Scheme 7: Synthesis of the 17-spiro-γ-lactone 23, a key intermediate to obtain spironolactone. a) Ethyl propi...
Scheme 8: Synthetic pathway to obtain 17-spirodihydrofuran-3(2H)-ones from 17-oxosteroids. a) 1-Methoxypropa-...
Scheme 9: One-pot procedure to obtain 17-spiro-2H-furan-3-one compounds. a) NaH, diethyl oxalate, benzene, rt...
Scheme 10: Synthesis of 17-spiro-2H-furan-3-one derivatives. a) RCH=NOH, N-chlorosuccinimide/CHCl3, 99%; b) H2...
Scheme 11: Intramolecular condensation of a γ-acetoxy-β-ketoester to synthesize spirofuranone 37. a) (CH3CN)2P...
Scheme 12: Synthesis of spiro 2,5-dihydrofuran derivatives. a) Allyl bromide, DMF, NaH, 0 °C to rt, 93%; b) G-...
Scheme 13: First reported synthesis of C-16 dispiropyrrolidine derivatives. a) Sarcosine, isatin, MeOH, reflux...
Scheme 14: Cycloadducts 47 with antiproliferative activity against human cancer cell lines. a) 1,4-Dioxane–MeO...
Scheme 15: Spiropyrrolidine compounds generated from (E)-16-arylidene steroids and different ylides. a) Acenap...
Scheme 16: 3-Spiropyrrolidines 52a–c obtained from ketones 50a–c. a) p-Toluenesulfonyl hydrazide, MeOH, rt; b)...
Scheme 17: 16-Spiropyrazolines from 16-methylene-13α-estrone derivatives. a) AgOAc, toluene, rt, 78–81%.
Scheme 18: 6-Spiroimidazolines 57 synthesized by a one-pot multicomponent reaction. a) R3-NC, T3P®, DMSO, 70 °...
Scheme 19: Synthesis of spiro-1,3-oxazolines 60, tested as progesterone receptor antagonist agents. a) CF3COCF3...
Scheme 20: Synthesis of spiro-1,3-oxazolidin-2-ones 63 and 66a,b. a) RNH2, EtOH, 70 °C, 70–90%; b) (CCl3O)2CO,...
Scheme 21: Formation of spiro 1,3-oxazolidin-2-one and spiro 2-substituted amino-4,5-dihydro-1,3-oxazoles from ...
Scheme 22: Synthesis of diastereomeric spiroisoxazolines 74 and 75. a) Ar-C(Cl)=N-OH, DIPEA, toluene, rt, 74 (...
Scheme 23: Spiro 1,3-thiazolidine derivatives 77–79 obtained from 2α-bromo-5α-cholestan-3-one 76. a) 2-aminoet...
Scheme 24: Method for the preparation of derivative 83. a) Benzaldehyde, MeOH, reflux, 77%; b) thioglycolic ac...
Scheme 25: Synthesis of spiro 1,3-thiazolidin-4-one derivatives from steroidal ketones. a) Aniline, EtOH, refl...
Scheme 26: Synthesis of spiro N-aryl-1,3-thiazolidin-4-one derivatives 91 and 92. a) Sulfanilamide, DMF, reflu...
Scheme 27: 1,2,4-Trithiolane dimers 94a–e selectively obtained from carbonyl derivatives. a) LR, CH2Cl2, reflu...
Scheme 28: Spiro 1,2,4-triazolidin-3-ones synthesized from semicarbazones. a) H2O2, CHCl3, 0 °C, 82–85%.
Scheme 29: Steroidal spiro-1,3,4-oxadiazoline 99 obtained in two steps from cholest-5-en-3-one (97). a) NH2NHC...
Scheme 30: Synthesis of spiro-1,3,4-thiadiazoline 101 by cyclization and diacetylation of thiosemicarbazone 100...
Scheme 31: Mono- and bis(1,3,4-thiadiazolines) obtained from estrane and androstane derivatives. a) H2NCSNHNH2...
Scheme 32: Different reaction conditions to synthesize spiro-1,3,2-oxathiaphospholanes 108 and 109.
Scheme 33: Spiro-δ-lactones derived from ADT and epi-ADT as inhibitors of 17β-HSDs. a) CH≡C(CH2)2OTHP, n-BuLi,...
Scheme 34: Spiro-δ-lactams 123a,b obtained in a five-step reaction sequence. a) (R)-(+)-tert-butylsulfinamide,...
Scheme 35: Steroid-coumarin conjugates as fluorescent DHT analogues to study 17-oxidoreductases for androgen m...
Scheme 36: 17-Spiro estradiolmorpholinones 130 bearing two types of molecular diversity. a) ʟ- or ᴅ-amino acid...
Scheme 37: Steroidal spiromorpholinones as inhibitors of enzyme 17β-HSD3. a) Methyl ester of ʟ- or ᴅ-leucine, ...
Scheme 38: Steroidal spiro-morpholin-3-ones achieved by N-alkylation or N-acylation of amino diols 141, follow...
Scheme 39: Straightforward method to synthesize a spiromorpholinone derivative from estrone. a) BnBr, K2CO3, CH...
Scheme 40: Pyrazolo[4,3-e][1,2,4]-triazine derivatives 152–154. a) 4-Aminoantipyrine, EtOH/DMF, reflux, 82%; b...
Scheme 41: One-pot procedure to synthesize spiro-1,3,4-thiadiazine derivatives. a) NH2NHCSCONHR, H2SO4, dioxan...
Scheme 42: 1,2,4-Trioxanes with antimalarial activity. a) 1. O2, methylene blue, CH3CN, 500 W tungsten halogen...
Scheme 43: Tetraoxanes 167 and 168 synthesized from ketones 163, 165 and 166. a) NaOH, iPrOH/H2O, 80 °C, 93%; ...
Scheme 44: 1,2,4,5-Tetraoxanes bearing a steroidal moiety and a cycloalkane. a) 30% H2O2/CH2Cl2/CH3CN, HCl, rt...
Scheme 45: Spiro-1,3,2-dioxaphosphorinanes obtained from estrone derivatives. a) KBH4, MeOH, THF or CH2Cl2; b)...
Scheme 46: Synthesis of steroidal spiro-ε-lactone 183. a) 1. Jones reagent, acetone, 0 °C to rt, 2. ClCOCOCl, ...
Scheme 47: Synthesis of spiro-2,3,4,7-tetrahydrooxepines 185 and 187 derived from mestranol and lynestrenol (38...
Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100
Graphical Abstract
Figure 1: Positional notation of 6,6-bonds in a mono-adduct of C60 with the first addition site indicated usi...
Scheme 1: Synthesis of silylene adducts 2 and 3.
Figure 2: Absorption spectrum of 3 in CH2Cl2.
Figure 3: 500 MHz 1H NMR spectrum of 3 in CDCl3/CS2 3:1.
Figure 4: 125 MHz 13C NMR spectrum of 3 in CDCl3/CS2 3:1. The signals of sp2 carbons of C60 and quaternary ca...
Figure 5: ORTEP drawing of 3 showing thermal ellipsoids at the 50% probability level at 100 K. Hydrogen atoms...
Figure 6: (a) Partial structures of isomers of Dip2SiC60. (b) Optimized structures of 2a and 2c. Hydrogen ato...
Figure 7: Optimized structures of 3cis-2, 3cis-3, 3e, 3trans-1, 3trans-2, 3trans-3, and 3trans-4. Values in p...
Figure 8: (a) LUMO and (b) HOMO of 2a calculated at the B3LYP/6-31G(d) level. Hydrogen atoms are omitted for ...
Figure 9: Cyclic voltammograms (CV) and differential pulse voltammograms (DPV) of 3 in o-dichlorobenzene cont...
Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92
Graphical Abstract
Figure 1: Chemical structures of H-bonding N-heteroacenes synthesized by Miao et al. and Bunz et al. (a) [22,23]. Pr...
Scheme 1: Synthesis of dicyanopyrazinoquinoxaline derivatives 1a–7a.
Scheme 2: Synthesis of bis-alkoxy-substituted π-conjugated phenanthrolines 16a, 16b, 16c, and 16d.
Scheme 3: An alternative synthetic route to access 7a.
Scheme 4: Synthesis of DPQDs 1b–7b from their corresponding DCPQs 1a–7a. *THF/H2O/1,4-dioxane (4:5:1). **in s...
Figure 2: TGA of 1a–6a (a) and 1b–7b (b) obtained at 10 °C/min under nitrogen.
Figure 3: Absorption spectra (20 μM) for a) DCPQs 1a–6a and b) DPQDs 1b–7b in dimethyl sulfoxide.
Figure 4: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 5: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 6: Asymmetric unit of DPQD 2b with important bond lengths highlighted (a). Torsion angles of 4.33° and...
Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41
Graphical Abstract
Scheme 1: Monofluorination of 1,3-diphenylpropane-1,3-dione with Selectfluor.
Scheme 2: Synthesis of 2,2-difluoro-1,3-diphenylpropane-1,3-dione (3a).
Figure 1: Molecular structure of 2,2-difluoro-1,3-diphenylpropane-1,3-dione (3a).
Figure 2: Crystal packing structure of 3f as determined by SXRC.
Figure 3: Molecular structure and crystal packing of 5e as determined by SXRC.
Scheme 3: Proposed mechanism of the quinuclidine-mediated difluorination of 1,3-dicarbonyl substrates.
Scheme 4: Proposed mechanisms of carbonate and chloride ion-mediated difluorination of 1,3-dicarbonyl substra...
Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36
Graphical Abstract
Scheme 1: Examples of BIMs used for their medicinal properties.
Scheme 2: Mechanisms for the synthesis of BIMs using protic or Lewis acids as catalysts.
Scheme 3: Synthesis of bis(indolyl)methanes using DBDMH.
Scheme 4: Competition experiments and synthesis of bis(indolyl)methanes using DBDMH.
Scheme 5: Proposed mechanism for formation of BIM of using DBDMH.
Scheme 6: Synthesis of bis(indolyl)methanes using I2.
Scheme 7: General reaction mechanism upon halogen bonding.
Scheme 8: Synthesis of bis(indolyl)methanes using I2, introduced by Ji.
Scheme 9: Synthesis of bis(indolyl)methanes using Br2 in CH3CN.
Scheme 10: Βidentate halogen-bond donors.
Scheme 11: Synthesis of bis(indolyl)methanes using bidentate halogen-bond donor 26.
Scheme 12: Proposed reaction mechanism.
Scheme 13: Synthesis of bis(indolyl)methanes using iodoalkyne as catalyst.
Scheme 14: Proposed reaction mechanism.
Scheme 15: Optimized reaction conditions used by Ramshini.
Scheme 16: Activation of the carbonyl group by HPA/TPI-Fe3O4.
Scheme 17: Synthesis of BIMs in the presence of nanoAg-Pt/SiO2-doped silicate.
Scheme 18: Mechanism of action proposed by Khalafi-Nezhad et al.
Scheme 19: Activation of the carbonyl group by the Cu–isatin Schiff base complex.
Scheme 20: Optimum reaction conditions published by Jain.
Scheme 21: Organocatalytic protocol utilizing nanoparticles introduced by Bankar.
Scheme 22: Activation of the carbonyl group by the AlCl3·6H2O-SDS-SiO2 complex.
Scheme 23: Optimal reaction conditions for the aforementioned nano-Fe3O4 based catalysts.
Scheme 24: Nanocatalytic protocol proposed by Kaur et al.
Scheme 25: Microwave approach introduced by Yuan.
Scheme 26: Microwave approach introduced by Zahran et al.
Scheme 27: Microwave irradiation protocol introduced by Bindu.
Scheme 28: Silica-supported microwave irradiation protocol.
Scheme 29: Proposed mechanism for formation of BIM by Nongkhlaw.
Scheme 30: Microwave-assisted synthesis of BIMs catalyzed by succinic acid.
Scheme 31: Proposed mechanism of action of MMO-4.
Scheme 32: Catalytic approach introduced by Muhammadpoor-Baltork et al.
Scheme 33: Reaction conditions used by Xiao-Ming.
Scheme 34: Ultrasonic irradiation-based protocol published by Saeednia.
Scheme 35: Pyruvic acid-mediated synthesis of BIMs proposed by Thopate.
Scheme 36: Synthesis of BIMs using [bmim]BF4 or [bmim]PF6 ionic liquids.
Scheme 37: Synthesis of BIMs utilizing In(OTf)3 in octylmethylimidazolium hexafluorophosphate as ionic liquid.
Scheme 38: FeCl3·6H2O-catalyzed synthesis of BIMs with use of ionic liquid.
Scheme 39: Synthesis of BIMs utilizing the [hmim]HSO4/EtOH catalytic system.
Scheme 40: Synthesis of BIMs utilizing acidic ionic liquid immobilized on silica gel (ILIS-SO2Cl).
Scheme 41: The [bmim][MeSO4]-catalyzed reaction of indole with various aldehydes.
Scheme 42: The role of [bmim][MeSO4] in catalyzing the reaction of indole with aldehydes.
Scheme 43: Synthesis of BIMs utilizing FeCl3-based ionic liquid ([BTBAC]Cl-FeCl3) as catalyst.
Scheme 44: Synthesis of BIMs using [Msim]Cl at room temperature.
Scheme 45: [Et3NH][H2PO4]-catalyzed synthesis of bis(indolyl)methanes.
Scheme 46: PILs-catalyzed synthesis of bis(indolyl)methanes.
Scheme 47: FSILs-mediated synthesis of bis(indolyl)methanes.
Scheme 48: Possible “release and catch” catalytic process.
Scheme 49: Synthesis of bis(indolyl)methanes by [DABCO-H][HSO4].
Scheme 50: Synthesis of bis(indolyl)methanes by [(THA)(SO4)].
Scheme 51: Synthesis of BBSI-Cl and BBSI-HSO4.
Scheme 52: Synthesis of BIMs in the presence of BBSI-Cl and BBSI-HSO4.
Scheme 53: Chemoselectivity of the present method.
Scheme 54: Synthesis of BIMs catalyzed by chitosan-supported ionic liquid.
Scheme 55: Proposed mechanism of action of CSIL.
Scheme 56: Optimization of the reaction in DESs.
Scheme 57: Synthesis of BIMs using ChCl/SnCl2 as DES.
Scheme 58: Synthesis of BIMs derivatives in presence of DES.
Scheme 59: BIMs synthesis in choline chloride/urea (CC/U).
Scheme 60: Flow chemistry-based synthesis of BIMs by Ley.
Scheme 61: Flow chemistry-based synthesis of BIMs proposed by Nam et al.
Scheme 62: Amino-catalyzed reaction of indole with propionaldehyde.
Scheme 63: Aminocatalytic synthesis of BIMs.
Scheme 64: Proposed mechanism for the aminocatalytic synthesis of BIMs.
Scheme 65: Enzymatic reaction of indole with aldehydes.
Scheme 66: Proposed mechanism for the synthesis of BIMs catalyzed by TLIM.
Scheme 67: Proposed reaction mechanism by Badsara.
Scheme 68: Mechanism proposed by D’Auria.
Scheme 69: Photoinduced thiourea catalysis.
Scheme 70: Proposed mechanism of photoacid activation.
Scheme 71: Proposed mechanism of action for CF3SO2Na.
Scheme 72: Proposed mechanism for the synthesis of BIMs by Mandawad.
Scheme 73: Proposed mechanism for the (a) acid generation and (b) synthesis of BIMs.
Scheme 74: a) Reaction conditions employed by Khaksar and b) activation of the carbonyl group by HFIP.
Scheme 75: Activation of the carbonyl group by the PPy@CH2Br through the formation of a halogen bond.
Scheme 76: Reaction conditions utilized by Mhaldar et al.
Scheme 77: a) Reaction conditions employed by López and b) activation of the carbonyl group by thiourea.
Scheme 78: Infrared irradiation approach introduced by Luna-Mora and his research group.
Scheme 79: Synthesis of BIMs with the use of the Fe–Zn BMOF.
Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30
Graphical Abstract
Scheme 1: “Precursor approach” for the synthesis of π-conjugated polycyclic compounds, with the thermally- or...
Scheme 2: Valence isomerization of chalcogen heteropines and subsequent cheletropic extrusion in the case of ...
Scheme 3: Early example of phenanthrene synthesis via a chemically-induced S-extrusion (and concomitant decar...
Scheme 4: Top: Conversion of dinaphthothiepine bisimides 3a,b and their sulfoxide analogues 4a,b into PBIs 6a,...
Figure 1: Top view (a) and side view (b) of the X-ray crystal structure of thiepine 3b showing its bent confo...
Scheme 5: Modular synthetic route towards dinaphthothiepines 3a–f and the corresponding S-oxides 4a–d, incorp...
Scheme 6: Top: Conversion of dithienobenzothiepine monomeric units into dithienonaphthalenes, upon S-extrusio...
Scheme 7: Synthesis of S-doped extended triphenylene derivative 22 from 3-bromothiophene (17) with the therma...
Scheme 8: Top: Synthesis of thermally-stable O-doped HBC 26a. Bottom: Synthesis of S- and Se-based soluble pr...
Scheme 9: Synthesis of dinaphthooxepine bisimide 33 and conversion into PBI 6f by O-extrusion triggered by el...
Figure 2: Cyclic voltammogram of dinaphthooxepine 33, evidencing the irreversibility of the reduction process...
Scheme 10: Top: Early example of 6-membered ring contraction with concomitant S-extrusion leading to dinaphtho...
Scheme 11: Examples of S-extrusion from annelated 1,2-dithiins under photoactivation (top) or thermal activati...
Scheme 12: Synthesis of dibenzo[1,4]dithiapentalene upon photoextrusion of SO2 [78].
Scheme 13: Extrusion of SO in naphthotrithiin-2-oxides for the synthesis of 2,5-dihydrothiophene 1-oxides [79].
Scheme 14: SO-extrusion as a key step in the synthesis of fullerenes (C60 and C70) encapsulating H2 molecules [80,82]....
Scheme 15: Synthesis of diepoxytetracene precursor 56 and its on-surface conversion into tetracene upon O-extr...
Scheme 16: Soluble precursors of hexacene, decacene and dodecacene incorporating 1,4-epoxides in their hydroca...
Scheme 17: Synthesis of tetraepoxide 59 as soluble precursor of decacene [85].
Figure 3: Constant-height STM measurement of decacene on Au(111) using a CO-functionalized tip (sample voltag...
Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6
Graphical Abstract
Scheme 1: Reaction of 1 with various Michael acceptors (EWG = electron-withdrawing group) forming the zwitter...
Figure 1: 1H NMR spectrum of 2a recorded on a 300 MHz spectrometer in CDCl3 at 23 °C; the inset shows a 3D-mo...
Figure 2: a) Molecular structure of 2a, hydrogen atoms omitted for clarity, thermal ellipsoids drawn at 30% p...
Figure 3: Left: UV–vis spectra of 2a, 2b and 2d in chloroform (straight lines) and in methanol (dotted lines)...
Figure 4: Conversion of 1 (initial c = 0.25 mM) toward 2a, 2b, or 2d in the presence of the respective Michae...
Scheme 2: Proposed mechanism for intramolecular proton transfer in zwitterion formation with Michael acceptor...
Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147
Graphical Abstract
Figure 1: Comparison of the hydration reactions of different alkynes in BMIm-BF4 catalysed by BF3·Et2O (blue)...
Scheme 1: Anodic oxidation of tetrafluoroborate anion.
Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138
Graphical Abstract
Scheme 1: Reaction of the La@C2v-C82 anion with benzyl bromide derivatives.
Figure 1: Changes in absorption spectra during the reaction of La@C2v-C82 anion with 1a.
Figure 2: HPLC profiles of the reaction mixture. Conditions: Buckyprep column (⌀ = 4.6 × 250 mm); eluent, tol...
Figure 3: HPLC profiles (Buckyprep column (⌀ = 4.6 × 250 mm); eluent, toluene; flow rate, 1.0 mL/min; UV dete...
Figure 4: Absorption spectra of 2, 3, 4, and 5 in CS2 and absorption spectra of C14, C10, C18, and C9 in Ce@C2...
Figure 5: ORTEP drawing of 3a with thermal ellipsoids shown at 50% probability level. Only an independent uni...
Figure 6: (a) Charge density of La@C2v-C82 anion as a function of its POAV values and (b) an enlarged part vi...
Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125
Graphical Abstract
Scheme 1: Structure of (A) 3-methylsalicylaldehyde 3,4,5-trimethoxybenzoyl hydrazone (hdz-CH3) and (B) 3-nitr...
Figure 1: ORTEP representation of the new N-acylhydrazones synthesized in the present work, drawn with therma...
Figure 2: (A) Superposition of molecular structures and stacked motifs of (B) hdz-CH3 and (C) hdz-NO2.
Figure 3: Overlap of the experimental (carbon atoms colored in gray) and theoretical structures (calculated w...
Figure 4: Mid-infrared spectra of the compounds. Experimental conditions: KBr pellets, room temperature. Calc...
Figure 5: 1H NMR (400 MHz) spectra of (A) hdz-CH3 and (B) hdz-NO2 in DMSO-d6 at 25 °C.
Figure 6: Electronic absorption spectra in a selected wavelength region for a solution of hdz-CH3 in 10% DMSO...
Figure 7: Electronic absorption spectra of hdz-NO2 in selected wavelength regions. Experimental conditions: l...
Scheme 2: General scheme for the synthesis of the studied hydrazones.
Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120
Graphical Abstract
Figure 1: Porphyrin and crown ether.
Figure 2: Timeline demonstrating the contributions into the crown ether–porphyrin chemistry.
Figure 3: Tetra-crowned porphyrin 1 and dimer 2 formed upon K+ binding.
Figure 4: meso-Crowned 25-oxasmaragdyrins 3a–c and their boron(III) complexes (3a–c)-BF2.
Scheme 1: CsF ion-pair binding of 4. The molecular structure of 4-CsF is shown on the right [101].
Figure 5: CsF ion pair binding by 5. The molecular structure of 5-CsF is shown on the right [102].
Scheme 2: Ion-pair binding by 6. The molecular structure of (6-CsCl)2 is shown on the right [103].
Scheme 3: Hydrated fluoride binding by 7 [104].
Figure 6: β-Crowned porphyrin 8.
Figure 7: Crown ether-capped porphyrins 9.
Figure 8: The capped porphyrin 10 and complex [10-PQ](PF6)2.
Figure 9: The double-capped porphyrin 11.
Figure 10: Selected examples of iminoporphyrinoids [58,122].
Scheme 4: The synthesis of 13.
Scheme 5: Tripyrrane-based crown ether-embedding porphyrinoid 15.
Figure 11: Macrocycles 16–19 and their coordination compounds.
Scheme 6: The flexibility of 16-Co [66].
Figure 12: Hexagonal wheel composed of six 16-Co(III) monomers [66].
Scheme 7: The synthesis of 16-V [67].
Figure 13: The molecular structure of dimers [16-Mn]2 [67].
Scheme 8: Synthesis of crownphyrins 28–33. Compounds 23a/b and 29a/b were obtained from 4,7,10-trioxa-1,13-tr...
Figure 14: The molecular structures of 22a, 34a·(HCl)2, and 29b [69].
Figure 15: Molecular structures of 22a-Pb and (29b)2-Zn [69].
Scheme 9: Reactivity of 29a/b.
Scheme 10: Synthesis of 36 and 37 [131].
Scheme 11: Synthesis of 40–45.
Figure 16: Potential applications of porphyrin-crown ether hybrids.
Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96
Graphical Abstract
Figure 1: Chemical structure of some natural ether lipids (ELs).
Figure 2: Synthesis of lyso-PAF and PAF from 1-O-alkylglycerol [64].
Figure 3: Synthesis of lyso-PAF from 1,3-benzylideneglycerol 3.1 [69].
Figure 4: A) Synthesis of the two enantiomers of octadecylglycerol (4.6 and 4.10) from ᴅ-mannitol (4.1); B) s...
Figure 5: Four-step synthesis of PAF 5.6 from (S)-glycidol [73].
Figure 6: Synthesis of 1-O-alkylglycerol A) from solketal, B) from ᴅ- or ʟ-tartaric acid and the intermediate ...
Figure 7: Synthesis of EL building blocks starting from substituted glycidol 7.1a–c [82].
Figure 8: Synthesis of PAF 8.5 by using phosphoramidite 8.2 [86].
Figure 9: Synthesis of oleyl-PAF 9.7 from ʟ-serine [88].
Figure 10: Synthesis of racemic analogues of lyso-PAF 10.8 and PAF 10.9 featuring a phenyl group between the g...
Figure 11: Synthesis of racemic deoxy-lyso-PAF 11.7 and deoxy-PAF 11.8 [91].
Figure 12: Synthesis of racemic thio-PAF 12.8 [93].
Figure 13: Racemic synthesis of 13.6 to illustrate the modification of the glycerol backbone by adding a methy...
Figure 14: Racemic synthesis of 14.5 as an illustration of the introduction of methyl substituents on the glyc...
Figure 15: Synthesis of functionalized sn-2-acyl chains of PC-EL; A) Steglich esterification or acylation reac...
Figure 16: Synthesis of racemic mc-PAF (16.3), a carbamate analogue of PAF [102].
Figure 17: A) Synthesis of (R)-17.2 and (S)-17.6 starting from (S)-solketal (17.1); B) synthesis of N3-PAF (17...
Figure 18: Modification of the phosphocholine polar head to produce PAF analogues [81].
Figure 19: Racemic PAF analogues 19.3 and 19.5 characterized by the absence of the phosphate group [107].
Figure 20: Synthesis of PIP3-PAF (20.7) [108].
Figure 21: Large-scale synthesis of C18-edelfosine (21.8) [116].
Figure 22: Synthesis of C16-edelfosine (22.10) starting from isopropylidene-ʟ-glyceric acid methyl ester (22.1...
Figure 23: Phosphocholine moiety installation by the use of chlorophosphite 23.2 as key reagent [119].
Figure 24: Synthesis of rac-1-alkyl-2-O-methylglycerol (AMG) [120].
Figure 25: Synthesis of stereocontrolled 1-alkyl-2-O-methyl glycerol 25.9 (AMG) from dimethyl ᴅ-tartrate [81].
Figure 26: A) Racemic synthesis of thioether 26.4 [129,130], B) structure of sulfone analogue 26.5 [129].
Figure 27: Stereocontrolled synthesis of C18-edelfosine thioether analogue 27.8 [118].
Figure 28: Synthesis of thioether 28.4 that include a thiophosphate function [134].
Figure 29: Synthesis of ammonium thioether 29.4 and 29.6 [135].
Figure 30: Synthesis of the N-methylamino analogue of edelfosine 30.6 (BN52211) [138].
Figure 31: Synthesis of 1-desoxy analogues of edelfosine; A) with a saturated alkyl chain; B) synthesis of the...
Figure 32: Stereocontrolled synthesis of edelfosine analogue (S)-32.8 featuring a C18:1 lipid chain [142].
Figure 33: Synthesis of edelfosine analogues with modulation of the lipid chain; A) illustration with the synt...
Figure 34: Synthesis of phospholipid featuring a carbamate function to link the lipid chain to the glycerol un...
Figure 35: Synthesis of sesquiterpene conjugates of phospho glycero ether lipids [148].
Figure 36: Racemic synthesis of methyl-substituted glycerol analogues 36.7 and 36.10: A) synthesis of diether ...
Figure 37: Racemic synthesis of ilmofosine (37.6) [155,156].
Figure 38: A) Stereoselective synthesis of 38.5 via a stereoselective hydroboration reaction; B) synthesis of ...
Figure 39: Racemic synthesis of SRI62-834 (39.6) featuring a spiro-tetrahydrofurane heterocycle in position 2 ...
Figure 40: Racemic synthesis of edelfosine analogue 40.5 featuring an imidazole moiety in sn-2 position [160].
Figure 41: Racemic synthesis of fluorine-functionalized EL: A) Synthesis of 41.6 and B) synthesis of 41.8 [161-163].
Figure 42: A) Synthesis of the β-keto-ester 42.6 that also features a decyl linker between the phosphate and t...
Figure 43: Synthesis of phosphonate-based ether lipids; A) edelfosine phosphonate analogue 43.7 and B) thioeth...
Figure 44: Enantioselective synthesis of phosphonates 44.3 and 44.4 [171].
Figure 45: Racemic synthesis of phosphinate-based ether lipid 45.10 [172].
Figure 46: Racemic synthesis of edelfosine arsonium analogue 46.5 [173].
Figure 47: Synthesis of edelfosine dimethylammonium analogue 47.2 [118].
Figure 48: Synthesis of rac-C18-edelfosine methylammonium analogue 48.4 [176].
Figure 49: A) Synthesis of edelfosine N-methylpyrrolidinium analogue 49.2 or N-methylmorpholinium analogue 49.3...
Figure 50: A) Synthesis of edelfosine’s analogue 50.4 with a PE polar group; B) illustration of a pyridinium d...
Figure 51: A) Synthesis of 51.4 featuring a thiazolium cationic moiety; B) synthesis of thiazolium-based EL 51...
Figure 52: Synthesis of cationic ether lipids 52.3, 52.4 and 52.6 [135,183].
Figure 53: Synthesis of cationic carbamate ether lipid 53.5 [184].
Figure 54: Synthesis of cationic sulfonamide 54.5 [185].
Figure 55: Chemical structure of ONO-6240 (55.1) and SRI-63-119 (55.2).
Figure 56: Synthesis of non-ionic ether lipids 56.2–56.9 [188].
Figure 57: Synthesis of ether lipid conjugated to foscarnet 57.6 [189].
Figure 58: A) Synthesis of ether lipid conjugated to arabinofuranosylcytosine; B) synthesis of AZT conjugated ...
Figure 59: Synthesis of quercetin conjugate to edelfosine [191].
Figure 60: Synthesis of 60.8 (Glc-PAF) [194].
Figure 61: A) Synthesis of amino ether lipid 61.7 functionalized with a rhamnose unit and its amide analogue 6...
Figure 62: A) Synthesis of glucose ether lipid 62.4; B) structure of ether lipid 62.5 possessing a maltose uni...
Figure 63: A) Synthesis of glucuronic methyl ester 63.8; B) structure of cellobiose 63.9 and maltose 63.10 ana...
Figure 64: A) Synthesis of maltosyl glycerolipid 64.7; B) structure of lactose analogue 64.8 prepared followin...
Figure 65: A) Asymmetric synthesis of the aglycone moiety starting from allyl 4-methoxyphenyl ether; B) glycos...
Figure 66: A) Synthesis of ohmline possessing a lactose moiety. B) Structure of other glyco glycero lipids pre...
Figure 67: A) Synthesis of lactose-glycerol ether lipid 67.5; B) analogues possessing a maltose (67.6) or meli...
Figure 68: Synthesis of digalactosyl EL 68.6, A) by using trityl, benzyl and acetyl protecting groups, B) by u...
Figure 69: A) Synthesis of α-ohmline; B) structure of disaccharide ether lipids prepared by using similar meth...
Figure 70: Synthesis of lactose ether lipid 70.3 and its analogue 70.6 featuring a carbamate function as linke...
Figure 71: Synthesis of rhamnopyranoside diether 71.4 [196].
Figure 72: Synthesis of 1-O-hexadecyl-2-O-methyl-3-S-(α-ᴅ-1'-thioglucopyranosyl)-sn-glycerol (72.5) [225].
Figure 73: A) Preparation of lipid intermediate 73.4; B) synthesis of 2-desoxy-C-glycoside 73.10 [226].
Figure 74: Synthesis of galactose-pyridinium salt 74.3 [228].
Figure 75: Synthesis of myo-inositol derivative Ino-C2-PAF (75.10) [230].
Figure 76: A) Synthesis of myo-inositol phosphate building block 76.7; B) synthesis of myo-inositolphosphate d...
Figure 77: A) Synthesis of phosphatidyl-3-desoxy-inositol 77.4; B) synthesis of phosphono-3-desoxyinositol 77.9...
Figure 78: A) Structure of diether phosphatidyl-myo-inositol-3,4-diphosphate 78.1; B) synthesis of phosphatidy...
Figure 79: A) Synthesis of diether-phosphatidyl derivative 79.4 featuring a hydroxymethyl group in place of a ...
Figure 80: Synthesis of Glc-amine-PAF [78].
Figure 81: Synthesis of glucosamine ether lipid 81.4 and its analogues functionalized in position 3 of the ami...
Figure 82: Synthesis of fully deprotected aminoglucoside ether lipid 82.5 [246].
Figure 83: Synthesis of C-aminoglycoside 83.12 using Ramberg–Bäcklund rearrangement as a key step [250].
Figure 84: A) List of the most important glyco lipids and amino glyco lipids included in the study of Arthur a...
Figure 85: Synthesis of mannosamine ether lipid 85.6 [254].
Figure 86: A) Synthesis of glucosamine ether lipids with a non-natural ʟ-glucosamine moiety; B) synthesis of e...
Figure 87: A) Structure of the most efficient anticancer agents 87.1–87.4 featuring a diamino glyco ether lipi...
Figure 88: A) Synthesis of diamino glyco ether lipid 87.4; B) synthesis of bis-glycosylated ether lipid 88.10 [256]....
Figure 89: Synthesis of triamino ether lipid 89.4 [260].
Figure 90: Synthesis of chlorambucil conjugate 90.7 [261].
Figure 91: Three main methods for the preparation of glycerol ether lipid 91.3; A) from solketal and via a tri...
Figure 92: Four different methods for the installation of the phosphocholine polar head group; A) method using...
Figure 93: Illustration of two methods for the installation of saccharides or aminosaccharides; A) O-glycosyla...
Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64
Graphical Abstract
Figure 1: a) Chemical structure of pseudorotaxanes 1; and (b) single-crystal X-ray structure of rotaxane 1a (R...
Figure 2: (a) Chemical structure of polyrotaxane 2; and (b) cartoon representation of the light-triggered deg...
Figure 3: a) Chemical structures of rotaxanes (E)-3 and (Z)-3; b) stick representation of the solid structure...
Figure 4: Stick representations of the solid structures of: (a) U-CB[8]-MPyVB showing an interlocked ligand c...
Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63
Graphical Abstract
Figure 1: Supramolecular assembly of TMeQ[6] and 1,2-bis(4-pyridyl)ethene (G).
Figure 2: (a) UV–vis titration of G (3.0 × 10−5 mol·L−1, pH 6.5) in aqueous solution with the increase of TMe...
Figure 3: (a) Fluorescence spectra (U = 550 V, pH 6.5) of G (3.0 × 10−5 mol·L−1) in aqueous solution with inc...
Figure 4: (a) Crystal structure of complex 1; (b) and (c) the binding mode of G with TMeQ[6]; (d) the supramo...
Figure 5: (a) Fluorescence response of G (3.0 × 10−5 mol·L−1) to metal cations in aqueous solution; (b) fluor...
Figure 6: Influence of coexisting ions on Hg2+ detection by G@TMeQ[6].
Figure 7: (a) Fluorescence titration curve (U = 500 V, pH 6.5) of probe G@TMeQ[6] (3.0 × 10−5 mol·L−1) to Hg2+...
Figure 8: (A) Titration 1H NMR spectra (400 MHz) obtained for TMeQ[6] with (a) 0.00, (b) 0.50, (c) 1.00 and (...
Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23
Graphical Abstract
Figure 1: Examples of terpenes containing a bicyclo[3.6.0]undecane motif.
Figure 2: Commercially available first and second generation Grubbs and Hoveyda–Grubbs catalysts.
Figure 3: Examples of strategies to access the fusicoccan and ophiobolin tricyclic core structure by RCM.
Scheme 1: Synthesis of bicyclic core structure 12 of ophiobolin M (13) and cycloaraneosene (14).
Scheme 2: Synthesis of the core structure 21 of ophiobolins and fusicoccanes.
Scheme 3: Ring-closing metathesis attempts starting from thioester 22.
Scheme 4: Total synthesis of ent-fusicoauritone (28).
Figure 4: General structure of ophiobolins and congeners.
Scheme 5: Total synthesis of (+)-ophiobolin A (8).
Scheme 6: Investigation of RCM for the synthesis of ophiobolin A (8). Path A) RCM with TBDPS-protected alcoho...
Scheme 7: Synthesis of the core structure of cotylenin A aglycon, cotylenol (50).
Scheme 8: Synthesis of tricyclic core structure of fusicoccans.
Scheme 9: Total synthesis of (−)-teubrevin G (59).
Scheme 10: Synthesis of the core skeleton 63 of the basmane family.
Scheme 11: Total synthesis of (±)-schindilactone A (68).
Scheme 12: Total synthesis of dactylol (72).
Scheme 13: Ring-closing metathesis for the total synthesis of (±)-asteriscanolide (2).
Scheme 14: Synthesis of the simplified skeleton of pleuromutilin (1).
Scheme 15: Total synthesis of (−)-nitidasin (93) using a ring-closing metathesis to construct the eight-member...
Scheme 16: Total synthesis of (±)-naupliolide (97).
Scheme 17: Synthesis of the A-B ring structure of fusicoccane (101).
Scheme 18: First attempts of TRCM of dienyne substrates.
Scheme 19: TRCM on optimized substrates towards the synthesis of ophiobolin A (8).
Scheme 20: Tandem ring-closing metathesis for the synthesis of variecolin intermediates 114 and 115.
Scheme 21: Synthesis of poitediol (118) using the allylsilane ring-closing metathesis.
Scheme 22: Access to scaffold 122 by a NHK coupling reaction.
Scheme 23: Key step to construct the [5-8] bicyclooctanone core of aquatolide (4).
Scheme 24: Initial strategy to access aquatolide (4).
Scheme 25: Synthetic plan to cotylenin A (130).
Scheme 26: [5-8] Bicyclic structure of brachialactone (7) constructed by a Mizoroki–Heck reaction.
Scheme 27: Influence of the replacement of the allylic alcohol moiety.
Scheme 28: Formation of variecolin intermediate 140 through a SmI2-mediated Barbier-type reaction.
Scheme 29: SmI2-mediated ketyl addition. Pleuromutilin (1) eight-membered ring closure via C5–C14 bond formati...
Scheme 30: SmI2-mediated dialdehyde cyclization cascade of [5-8-6] pleuromutilin scaffold 149.
Scheme 31: A) Modular synthetic route to mutilin and pleuromutilin family members by Herzon’s group. B) Scaffo...
Scheme 32: Photocatalyzed oxidative ring expansion in pleuromutilin (1) total synthesis.
Scheme 33: Reductive radical cascade cyclization route towards (−)-6-epi-ophiobolin N (168).
Scheme 34: Reductive radical cascade cyclization route towards (+)-6-epi-ophiobolin A (173).
Scheme 35: Radical 8-endo-trig-cyclization of a xanthate precursor.
Figure 5: Structural representations of hypoestin A (177), albolic acid (178), and ceroplastol II (179) beari...
Scheme 36: Synthesis of the common [5-8-5] tricyclic intermediate of hypoestin A (177), albolic acid (178), an...
Scheme 37: Asymmetric synthesis of hypoestin A (177), albolic acid (178), and ceroplastol II (179).
Figure 6: Scope of the Pauson–Khand reaction.
Scheme 38: Nazarov cyclization revealing the fusicoauritone core structure 192.
Scheme 39: Synthesis of fusicoauritone (28) through Nazarov cyclization.
Scheme 40: (+)-Epoxydictymene (5) synthesis through a Nicholas cyclization followed by a Pauson–Khand reaction...
Scheme 41: Synthesis of aquatolide (4) by a Mukaiyama-type aldolisation.
Scheme 42: Tandem Wolff/Cope rearrangement furnishing the A-B bicyclic moiety 204 of variecolin.
Scheme 43: Asymmetric synthesis of the A-B bicyclic core 205 and 206 of variecolin.
Scheme 44: Formation of [5-8]-fused rings by cyclization under thermal activation.
Scheme 45: Construction of the [5-8-6] tricyclic core structure of variecolin (3) by Diels–Alder reaction.
Scheme 46: Synthesis of the [6-4-8-5]-tetracyclic skeleton by palladium-mediated cyclization.
Scheme 47: Access to the [5-8] bicyclic core structure of asteriscanolide (227) through rhodium-catalyzed cycl...
Scheme 48: Total syntheses of asterisca-3(15),6-diene (230) and asteriscanolide (2) with a Rh-catalyzed cycliz...
Scheme 49: Photocyclization of 2-pyridones to access the [5-8-5] backbone of fusicoccanes.
Scheme 50: Total synthesis of (+)-asteriscunolide D (245) and (+)-aquatolide (4) through photocyclization.
Scheme 51: Biocatalysis pathway to construct the [5-8-5] tricyclic scaffold of brassicicenes.
Scheme 52: Influence of the CotB2 mutant over the cyclization’s outcome of GGDP.
Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179
Graphical Abstract
Scheme 1: Organocatalysis classification used in the present perspective.
Scheme 2: Oxidative processes catalyzed by amines.
Scheme 3: N-Heterocyclic carbene (NHC) catalysis in oxidative functionalization of aldehydes.
Scheme 4: Examples of asymmetric oxidative processes catalyzed by chiral Brønsted acids.
Scheme 5: Asymmetric aerobic α-hydroxylation of lactams under phase-transfer organocatalysis conditions emplo...
Scheme 6: Selective CH-oxidation of methylarenes to aldehydes or carboxylic acids.
Scheme 7: An example of the regioselective CH-amination by a sterically hindered imide-N-oxyl radical precurs...
Scheme 8: CH-amination of ethylbenzene and CH-fluorination of aldehydes catalyzed by N-hydroxybenzimidazoles,...
Scheme 9: Mixed hetero-/homogeneous TiO2/N-hydroxyimide photocatalysis in the selective benzylic oxidation.
Scheme 10: Electrochemical benzylic iodination and benzylation of pyridine by benzyl iodides generated in situ...
Scheme 11: Electrochemical oxidative C–O/C–N coupling of alkylarenes with NHPI. Electrolysis conditions: Const...
Scheme 12: Chemoselective alcohol oxidation catalyzed by TEMPO.
Scheme 13: ABNO-catalyzed oxidative C–N coupling of primary alcohols with primary amines.
Scheme 14: ACT-catalyzed electrochemical oxidation of primary alcohols and aldehydes to carboxylic acids.
Scheme 15: Electrocatalytic oxidation of benzylic alcohols by a TEMPO derivative immobilized on a graphite ano...
Scheme 16: Electrochemical oxidation of carbamates of cyclic amines to lactams and oxidative cyanation of amin...
Scheme 17: Hydrogen atom transfer (HAT) and single-electron transfer (SET) as basic principles of amine cation...
Scheme 18: Electrochemical quinuclidine-catalyzed oxidation involving unactivated C–H bonds.
Scheme 19: DABCO-mediated photocatalytic C–C cross-coupling involving aldehyde C–H bond cleavage.
Scheme 20: DABCO-derived cationic catalysts in inactivated C–H bond cleavage for alkyl radical addition to ele...
Scheme 21: Electrochemical diamination and dioxygenation of vinylarenes catalyzed by triarylamines.
Scheme 22: Electrochemical benzylic oxidation mediated by triarylimidazoles.
Scheme 23: Thiyl radical-catalyzed CH-arylation of allylic substrates by aryl cyanides.
Scheme 24: Synthesis of redox-active alkyl tetrafluoropyridinyl sulfides by unactivated C–H bond cleavage by t...
Scheme 25: Main intermediates in quinone oxidative organocatalysis.
Scheme 26: Electrochemical DDQ-catalyzed intramolecular dehydrogenative aryl–aryl coupling.
Scheme 27: DDQ-mediated cross-dehydrogenative C–N coupling of benzylic substrates with azoles.
Scheme 28: Biomimetic o-quinone-catalyzed benzylic alcohol oxidation.
Scheme 29: Electrochemical synthesis of secondary amines by oxidative coupling of primary amines and benzylic ...
Scheme 30: General scheme of dioxirane and oxaziridine oxidative organocatalysis.
Scheme 31: Dioxirane organocatalyzed CH-hydroxylation involving aliphatic C(sp3)–H bonds.
Scheme 32: Enantioselective hydroxylation of CH-acids catalyzed by chiral oxaziridines.
Scheme 33: Iodoarene-organocatalyzed vinylarene diamination.
Scheme 34: Iodoarene-organocatalyzed asymmetric CH-hydroxylation of benzylic substrates.
Scheme 35: Iodoarene-organocatalyzed asymmetric difluorination of alkenes with migration of aryl or methyl gro...
Scheme 36: Examples of 1,2-diiodo-4,5-dimethoxybenzene-catalyzed electrochemical oxidative heterocyclizations.
Scheme 37: Electrochemical N-ammonium ylide-catalyzed CH-oxidation.
Scheme 38: Oxidative dimerization of aryl- and alkenylmagnesium compounds catalyzed by quinonediimines.
Scheme 39: FLP-catalyzed dehydrogenation of N-substituted indolines.
Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157
Graphical Abstract
Figure 1: ORTEP representation of triferrocenyl trithiophosphite showing 50% probability thermal ellipsoids.
Figure 2: Optimized conformations and relative energies of four possible conformers of triferrocenyl trithiop...
Figure 3: Calculated NBO charges on the Fe ions and hydrogen atoms for the optimized ttg conformer (left) and...
Figure 4: Molecular structures in the solid state of a) (FcS)3P, b) (FcS)3PO [19], and c) (FcS)3PS [7] as establishe...
Figure 5: Quantum chemically optimized conformations of the (PhS)3P molecule and their relative energies (kca...