Search for "indium" in Full Text gives 86 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
Graphical Abstract
Scheme 1: Features of the ideal reaction (redrawn from P. A. Wender et al. [1]).
Scheme 2: Some of the most popular MCRs with formaldehyde as the carbonyl component.
Scheme 3: Ugi reaction under a catalyzed electro-oxidation process using TEMPO (2,2,6,6-tetramethyl-1-piperid...
Scheme 4: Examples of different products obtained by MCRs in which DMSO serves as -SCH3 source.
Scheme 5: Mechanism of the decomposition of DMSO under acidic or thermal conditions. a) In situ generation of...
Scheme 6: Povarov multicomponent reaction to quinolines.
Scheme 7: Example of the Povarov reaction with formaldehyde with a julolidine derivative as main product.
Scheme 8: Povarov multicomponent reaction to quinoline derivatives I and II using DMSO as formaldehyde surrog...
Scheme 9: Example of a Povarov three-component reaction with change of catalyst, yielding regioisomer III. In...
Scheme 10: The Povarov three-component reactions carried out under acidic catalysis to afford quinoline regios...
Scheme 11: Different MCR routes involving DMSO to synthesize complex heterocycles such as diarylpyridines and ...
Scheme 12: Pyrazole synthesis by a three-component reaction using DMSO as a source of a C-1 unit.
Scheme 13: Three-component reactions for the synthesis of aliphatic heterocycles 13 and 14 using DMSO as a for...
Scheme 14: Proposed mechanism for the 3CR between homoallylic amines, disulfides, and DMSO.
Scheme 15: Mannich-type reaction using DMSO as formaldehyde surrogate.
Scheme 16: Mechanism for the 3CR-Mannich-type reaction between aryl ketone 18, saccharine (19), and DMSO. The ...
Scheme 17: Mannich-type reaction using DMSO as formaldehyde surrogate and under oxidative activation.
Scheme 18: Three-component reaction between an indazole, a carboxylic acid, and DMSO.
Scheme 19: Amine–aldehyde–alkyne (AAA) coupling reaction and plausible mechanism.
Scheme 20: AHA coupling for the synthesis of propargylamines using dihalomethanes as C1 building blocks.
Scheme 21: AHA coupling using CH2Cl2 as both solvent and methylene source.
Scheme 22: Examples of propargylamines synthesized under catalytic AHA protocols.
Scheme 23: Proposed mechanism for the synthesis of propargylamines using dichloromethane as a C1 source.
Scheme 24: Mechanism proposed for the generation of the aminal intermediate E by Buckley et al. [68].
Scheme 25: Pudovic and Kabachnik–Fields reactions for the synthesis of α-aminophosphonates.
Scheme 26: a) Abramov side reaction that generates α-hydroxy phosphonate as a byproduct during the Kabachnik-F...
Scheme 27: Catalyst-free three component reaction to afford α-amino phosphorus product 35 using 1,1-dihaloalka...
Scheme 28: a) Proposed mechanism for the three-component reaction of dichloromethane, amine and phosphorus com...
Scheme 29: Ugi-ammonia strategy using HMTA as a formaldehyde surrogate.
Scheme 30: Glyoxylate and its derivatives as C1 building blocks.
Scheme 31: The Groebke–Blackburn–Bienaymé multicomponent reaction (GBB) and its mechanism.
Scheme 32: a) Byproducts in the GBB multicomponent reaction (GBB) when formaldehyde is used as the carbonyl co...
Scheme 33: Possible regioisomers in the GBB multicomponent reaction when formaldehyde is used as the carbonyl ...
Scheme 34: The multicomponent GBB reaction yields 2-unsubstituted 3-aminoimidazo heterocycles 42a using MP-gly...
Scheme 35: GBB multicomponent reaction to 2-unsubstituted 3-amino imidazo heterocycles 42a using glyoxylic aci...
Scheme 36: GBB reaction using glyoxylic acid immobilized on silica as formaldehyde surrogate.
Scheme 37: Bioactive products synthesized by the GBB reaction using glyoxylic acid.
Scheme 38: van Leusen three-component reaction to imidazoles.
Scheme 39: Side reaction during the synthesis of imidazoles with formaldehyde as the carbonyl compound.
Scheme 40: Optimization of the van Leusen three component reaction to 1,4-disubstituted imidazoles 43 using gl...
Scheme 41: Application of the Sisko strategy [96] for the synthesis of CB1 receptor antagonist compounds [97].
Scheme 42: Side reaction, when NH4OH is used as amine component.
Scheme 43: Ugi-type adducts with the ester moiety and the acidic CH to be used for post-cyclization sequences.
Scheme 44: Ugi/cycloisomerization process to pyrrolones 51, butenolides 52, and pyrroline 53.
Scheme 45: Radical cyclization reactions from Ugi adducts promoted by TEMPO.
Scheme 46: Hydrolysis and decarboxylation reactions to products with incorporation of a C1 unit of ethyl glyox...
Scheme 47: One-step synthetic route to pyrrolones 60 using phenylglyoxal.
Scheme 48: Ugi-pseudo-Knoevenagel-pseudo-Dieckmann cascade sequence for the synthesis of fused heterocycles.
Scheme 49: Ugi-pseudo-Knoevenagel reaction from ethyl glyoxylate.
Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189
Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109
Graphical Abstract
Figure 1: Characterization data. (a) FTIR spectra of t-Bu-FIDO and t-Bu-FIDS. (b) UV–vis spectra of fullerene...
Figure 2: Single-crystal structure of t-Bu-FIDS. (a) The π–π distance between two molecules. (b) Crystal pack...
Figure 3: Cyclic voltammograms of fullerene derivatives in o-DCB solution containing Bu4N+(CF3SO2)2N− (0.1 M)...
Figure 4: J–V curves of BHJ OPV devices. (a) ITO/ZnO/fullerene:P3HT (1:1, w/w)/PEDOT:PSS/Ag. (b) ITO/ZnO/full...
Beilstein J. Org. Chem. 2024, 20, 1011–1019, doi:10.3762/bjoc.20.89
Graphical Abstract
Figure 1: XPS spectra for ACFs and FeCp2-ACFs-150. Peaks without labels originate from the indium substrate u...
Figure 2: XPS spectrum for FeCp2-ACFs-150 in the Fe2p region shown with fitting curves.
Figure 3: XPS spectra of (left) FeCp2-ACFs-150 and (right) ACFs in the C1s region with fitting curves.
Figure 4: Raman spectra for ACFs and FeCp2-ACFs-150. Each raw data (black) was fitted to the G-band (blue) an...
Figure 5: The raw infrared spectrum for FeCp2 (black) and differential absorbance spectra for FeCp2-ACFs-55 (...
Figure 6: The temperature (T) dependence of the magnetic susceptibility χ for FeCp2-ACFs-150, ACFs, and FeCp2...
Figure 7: a) ESR spectra of ACFs and FeCp2-ACFs-55 with different excitation microwave power. Each spectrum w...
Figure 8: The square root of the excitation microwave power dependence of the relative ESR intensities for AC...
Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139
Graphical Abstract
Figure 1: Chemical structures of pyridine-3,5-dicarbonitrile-based TADF emitters.
Scheme 1: Synthesis of dicyanocarbazole 6. Reaction conditions: a) cyanoacetamide, piperidine, methanol, 40 °...
Scheme 2: Synthesis of dicyanocarbazoles 7–9. Reaction conditions: a) corresponding ethynyl arene, Pd(Ph3P)4 ...
Figure 2: Absorption (a, b) and PL (c, d) spectra of dilute toluene, THF, and chloroform solutions (10−5 M) a...
Figure 3: PL spectra (a) and PL decay curves (b) of air-equilibrated (as prepared) and deoxygenated toluene s...
Figure 4: Non-normalized (a) and normalized (b) PL spectra and PL decay curves (c) of the film of a 10 wt % m...
Figure 5: TGA (a) and DSC 2nd heating (b) curves of compounds 6–9.
Figure 6: CV curves of compounds 6–9.
Figure 7: Photoelectron emission spectra of the vacuum-deposited films of compounds 6–9 on glass substrates c...
Figure 8: The current transients (a) for electrons recorded at the different voltages for the vacuum-deposite...
Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128
Graphical Abstract
Scheme 1: Molecular structures of compounds 1 and 2.
Figure 1: Raman spectra of 1 (a) and 2 (b) in powder.
Figure 2: XRD measurements of 1 (a) and 2 (b) captured on cooling from the isotropic phase, indicating the Mi...
Figure 3: Absorption and PL in chloroform solution and in spin-coated films for compounds 1 (a) and 2 (b). Th...
Figure 4: PL as a function of temperature for 1 (a) and 2 (b) casting films on heating. Left: PL spectra; rig...
Figure 5: AFM images of spin-coated films of compound 1 (a, c) and compound 2 (b, d) on PEDOT:PSS (a, b) and ...
Figure 6: Log–log plot of the J–V curves of the hole-only (a,b) and electron-only (c,d) of 1 (a,c) and 2 (b,d...
Figure 7: Charge carrier mobility as a function of the applied electric field obtained for the hole-only and ...
Figure 8: Ground state geometry (a) of compounds 1-iso and 2-iso obtained within B3LYP/def-TZVP(-f) level of ...
Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122
Graphical Abstract
Scheme 1: Synthesis of D–A–D chromophore TPECNz.
Figure 1: a) The optimized structure and HOMO/LUMO distributions calculated by B3LYP/6-31G(d,p) method. b) Th...
Figure 2: UV–vis absorption and PL spectra in a) toluene solution (≈1 × 10−5 M) and b) thin film spin-coated ...
Figure 3: a) Normalized UV–vis absorption/PL spectra in different solvents. b) Lippert–Mataga plot of Stokes ...
Figure 4: a) PL spectra in THF/water mixtures (5 μM) with different water fractions (fw). b) Plot of relative...
Figure 5: a) DSC and TGA thermograms measured at a heating rate of 10 °C min−1 under N2 flow. b) Cyclic volta...
Figure 6: a) Schematic structure of the hole-only and electron-only MIS devices. b) Electric-field dependence ...
Figure 7: a) Schematic energy diagram of OLED and organic materials used in the device. b) EL spectra at vari...
Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94
Graphical Abstract
Scheme 1: Research progress of coupling reactions and active compounds containing α-C(sp3)-functionalized eth...
Scheme 2: Transition-metal-catalyzed CDC pathways.
Scheme 3: CDC of active methylene compounds in the α-C(sp3) position of ethers.
Scheme 4: InCl3/Cu(OTf)2/NHPI co-catalyzed CDC reaction.
Scheme 5: CDC of cyclic benzyl ethers with aldehydes.
Scheme 6: Cu-catalyzed CDC of (a) unactivated C(sp3)–H ethers with simple ketones and (b) double C(sp3)−H fun...
Scheme 7: Cu-catalyzed CDC of C(sp3)–H/C(sp3)–H bonds.
Scheme 8: Cu-catalyzed synthesis of chiral 2-substituted tetrahydropyrans.
Scheme 9: CDC of thiazole with cyclic ethers.
Scheme 10: Cu(I)-catalyzed oxidative alkenylation of simple ethers.
Scheme 11: Cross-dehydrogenation coupling of isochroman C(sp3)–H bonds with anisole C(sp2)–H bonds.
Scheme 12: Pd(OAc)2/Cu(OTf)2-catalyzed arylation of α-C(sp3)–H bonds of ethers.
Scheme 13: Cu-catalyzed C(sp3)–H/C(sp2)–H activation strategies to construct C(sp3)–C(sp2) bonds.
Scheme 14: Cu(I)-catalyzed C(sp2)–H alkylation.
Scheme 15: Cu-catalyzed C(sp3)–H/C(sp)–H activation to construct C(sp3)–C(sp) bonds (H2BIP: 2,6-bis(benzimidaz...
Scheme 16: Fe-catalyzed CDC reaction pathways.
Scheme 17: Fe2(CO)9-catalyzed functionalization of C–H bonds.
Scheme 18: Ligand-promoted Fe-catalyzed CDC reaction of N-methylaniline with ethers.
Scheme 19: Fe-catalyzed CDC of C(sp3)–H/C(sp3)–H bonds.
Scheme 20: Fe-catalyzed hydroalkylation of α,β-unsaturated ketones with ethers.
Scheme 21: Solvent-free Fe(NO3)3-catalyzed CDC of C(sp3)–H/C(sp2)–H bonds.
Scheme 22: Alkylation of disulfide compounds to afford tetrasubstituted alkenes.
Scheme 23: Fe-catalyzed formation of 1,1-bis-indolylmethane derivatives.
Scheme 24: Alkylation of coumarins and flavonoids.
Scheme 25: Direct CDC α-arylation of azoles with ethers.
Scheme 26: CDC of terminal alkynes with C(sp3)–H bonds adjacent to oxygen, sulfur or nitrogen atoms.
Scheme 27: Alkylation of terminal alkynes.
Scheme 28: Co-catalyzed functionalization of glycine esters.
Scheme 29: Co-catalyzed construction of C(sp2)–C(sp3) bonds.
Scheme 30: Co-catalyzed CDC of imidazo[1,2-a]pyridines with isochroman.
Scheme 31: Co-catalyzed C–H alkylation of (benz)oxazoles with ethers.
Scheme 32: Cobalt-catalyzed CDC between unactivated C(sp2)–H and C(sp3)–H bonds.
Scheme 33: MnO2-catalyzed CDC of the inactive C(sp3)-H.
Scheme 34: Oxidative cross-coupling of ethers with enamides.
Scheme 35: Ni(II)-catalyzed CDC of indoles with 1,4-dioxane.
Scheme 36: Chemo- and regioselective ortho- or para-alkylation of pyridines.
Scheme 37: Asymmetric CDC of 3,6-dihydro-2H-pyrans with aldehydes.
Scheme 38: CDC of heterocyclic aromatics with ethers.
Scheme 39: Indium-catalyzed alkylation of DHPs with 1,3-dicarbonyl compounds.
Scheme 40: Rare earth-metal-catalyzed CDC reaction.
Scheme 41: Visible-light-driven CDC of cycloalkanes with benzazoles.
Scheme 42: Photoinduced alkylation of quinoline with cyclic ethers.
Scheme 43: Photocatalyzed CDC reactions between α-C(sp3)–H bonds of ethers and C(sp2)–H bonds of aromatics.
Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28
Graphical Abstract
Scheme 1: Group 13 exchange.
Scheme 2: Borane-catalysed hydroboration of alkynes and the proposed mechanism.
Scheme 3: a) Borane-catalysed hydroboration of alkenes and the proposed mechanism. b) H-B-9-BBN-catalysed dou...
Scheme 4: a) Amine-borane-catalysed C‒H borylation of heterocycles and the proposed mechanism. b) Benzoic aci...
Scheme 5: Bis(pentafluorophenyl)borane-catalysed dimerisation of allenes and the proposed mechanism.
Scheme 6: Alkoxide-promoted hydroboration of heterocycles and the proposed mechanism.
Scheme 7: Borane-catalysed reduction of indoles and the proposed mechanism.
Scheme 8: H-B-9-BBN-catalysed hydrocyanation of enones and the proposed mechanism.
Scheme 9: Borane-catalysed hydroboration of nitriles and the proposed mechanism.
Scheme 10: Myrtanylborane-catalysed asymmetric reduction of propargylic ketones and the proposed mechanism.
Scheme 11: H-B-9-BBN-catalysed C–F esterification of alkyl fluorides and the proposed mechanism.
Scheme 12: H-B-9-BBN-catalysed 1,4-hydroboration of enones and the proposed mechanism.
Scheme 13: Boric acid-promoted reduction of esters, lactones, and carbonates and the proposed mechanism.
Scheme 14: H-B-9-BBN-catalysed reductive aldol-type reaction and the proposed mechanism.
Scheme 15: H-B-9-BBN-catalysed diastereoselective allylation of ketones and the Ph-BBD-catalysed enantioselect...
Scheme 16: H-B-9-BBN-catalysed C–F arylation of benzyl fluorides and the proposed mechanism.
Scheme 17: Borane-catalysed S‒H borylation of thiols and the proposed mechanism.
Scheme 18: Borane-catalysed hydroalumination of alkenes and allenes.
Scheme 19: a) Aluminium-catalysed hydroboration of alkynes and example catalysts. b) Deprotonation mechanistic...
Scheme 20: Aluminium-catalysed hydroboration of alkenes and the proposed mechanism.
Scheme 21: Aluminium-catalysed C–H borylation of terminal alkynes and the proposed mechanism.
Scheme 22: Aluminium-catalysed dehydrocoupling of amines, alcohols, and thiols with H-B-9-BBN or HBpin and the...
Scheme 23: Aluminium-catalysed hydroboration of unsaturated compounds and the general reaction mechanism.
Scheme 24: a) Gallium-catalysed asymmetric hydroboration of ketones and the proposed mechanism. b) Gallium-cat...
Scheme 25: Gallium(I)-catalysed allylation/propargylation of acetals and aminals and the proposed mechanism.
Scheme 26: Indium(I)-catalysed allylation/propargylation of acetals, aminals, and alkyl ethers.
Scheme 27: Iron–indium cocatalysed double hydroboration of nitriles and the proposed mechanism.
Figure 1: a) The number of reports for a given group 13 exchange in catalysis. b) Average free energy barrier...
Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25
Graphical Abstract
Scheme 1: Tosylation of β-CD under continuous flow conditions.
Scheme 2: Continuous flow azidation of Ts-β-CD (2).
Scheme 3: Continuous flow hydrogenation of N3-β-CD (3).
Scheme 4: Semi-continuous flow system for the synthesis of NH2-β-CD 4.
Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136
Graphical Abstract
Figure 1: Chemical structures of (a) reported ionic TADF emitters for LEECs, (b) the MR-TADF emitter DiKTa an...
Scheme 1: Synthesis of DiKTa-OBuIm and DiKTa-DPA-OBuIm.
Figure 2: (a) HOMO and LUMO electron density distribution and orbital energies of DiKTa-OMe and DiKTa-DPA-OMe...
Figure 3: (a) Cyclic and differential pulse voltammograms measured in degassed MeCN with 0.1 M [n-Bu4N]PF6 as...
Figure 4: (a) Steady-state emission spectra of DiKTa-OBuIm and DiKTa-DPA-OBuIm in 1 wt % doped mCP films, λex...
Figure 5: (a) Electroluminescence spectra of DiKTa-OBuIm (green curve), DiKTa-DPA-OBuIm (red curve) and 1% of ...
Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43
Graphical Abstract
Figure 1: Natural bioactive naphthoquinones.
Figure 2: Chemical structures of vitamins K.
Figure 3: Redox cycle of menadione.
Scheme 1: Selected approaches for menadione synthesis using silver(I) as a catalyst.
Scheme 2: Methylation approaches for the preparation of menadione from 1,4-naphthoquinone using tert-butyl hy...
Scheme 3: Methylation approach of 1,4-naphthoquinone using i) rhodium complexes/methylboronic acid and ii) bi...
Scheme 4: Synthesis of menadione (10) from itaconic acid.
Scheme 5: Menadione synthesis via Diels–Alder reaction.
Scheme 6: Synthesis of menadione (10) using p-cresol as a synthetic precursor.
Scheme 7: Synthesis of menadione (10) via demethoxycarbonylating annulation of methyl methacrylate.
Scheme 8: Furan 34 used as a diene in a Diels–Alder reaction for the synthesis of menadione (10).
Scheme 9: o-Toluidine as a dienophile in a Diels–Alder reaction for the synthesis of menadione (10).
Scheme 10: Representation of electrochemical synthesis of menadione.
Figure 4: Reaction sites and reaction types of menadione as substrate.
Scheme 11: DBU-catalyzed epoxidation of menadione (10).
Scheme 12: Phase-transfer catalysis for the epoxidation of menadione.
Scheme 13: Menadione epoxidation using a hydroperoxide derived from (+)-norcamphor.
Scheme 14: Enantioselective Diels–Alder reaction for the synthesis of asymmetric quinone 50 catalyzed by a chi...
Scheme 15: Optimized reaction conditions for the synthesis of anthra[9,1-bc]pyranone.
Scheme 16: Synthesis of anthra[9,1-bc]furanone, anthra[9,1-bc]pyridine, and anthra[9,1-bc]pyrrole derivatives.
Scheme 17: Synthesis of derivatives employing protected trienes.
Scheme 18: Synthesis of cyclobutene derivatives of menadione.
Scheme 19: Menadione reduction reactions using sodium hydrosulfite.
Scheme 20: Green methodology for menadiol synthesis and pegylation.
Scheme 21: Menadione reduction by 5,6-O-isopropylidene-ʟ-ascorbic acid under UV light irradiation.
Scheme 22: Selected approaches of menadione hydroacetylation to diacetylated menadiol.
Scheme 23: Thiele–Winter reaction catalyzed by Bi(OTf)3.
Scheme 24: Carbonyl condensation of menadione using resorcinol and a hydrazone derivative.
Scheme 25: Condensation reaction of menadione with thiosemicarbazide.
Scheme 26: Condensation reaction of menadione with acylhydrazides.
Scheme 27: Menadione derivatives functionalized with organochalcogens.
Scheme 28: Synthesis of selenium-menadione conjugates derived from chloromethylated menadione 84.
Scheme 29: Menadione alkylation by the Kochi–Anderson method.
Scheme 30: Menadione alkylation by diacids.
Scheme 31: Menadione alkylation by heterocycles-substituted carboxylic acids.
Scheme 32: Menadione alkylation by bromoalkyl-substituted carboxylic acids.
Scheme 33: Menadione alkylation by complex carboxylic acids.
Scheme 34: Kochi–Anderson method variations for the menadione alkylation via oxidative decarboxylation of carb...
Scheme 35: Copper-catalyzed menadione alkylation via free radicals.
Scheme 36: Nickel-catalyzed menadione cyanoalkylation.
Scheme 37: Iron-catalyzed alkylation of menadione.
Scheme 38: Selected approaches to menadione alkylation.
Scheme 39: Menadione acylation by photo-Friedel–Crafts acylation reported by Waske and co-workers.
Scheme 40: Menadione acylation by Westwood procedure.
Scheme 41: Synthesis of 3-benzoylmenadione via metal-free TBAI/TBHP system.
Scheme 42: Michael-type addition of amines to menadione reported by Kallmayer.
Scheme 43: Synthesis of amino-menadione derivatives using polyalkylamines.
Scheme 44: Selected examples for the synthesis of different amino-substituted menadione derivatives.
Scheme 45: Selected examples of Michael-type addition of complex amines to menadione (10).
Scheme 46: Addition of different natural α-amino acids to menadione.
Scheme 47: Michael-type addition of amines to menadione using silica-supported perchloric acid.
Scheme 48: Indolylnaphthoquinone or indolylnaphthalene-1,4-diol synthesis reported by Yadav et al.
Scheme 49: Indolylnaphthoquinone synthesis reported by Tanoue and co-workers.
Scheme 50: Indolylnaphthoquinone synthesis from menadione by Escobeto-González and co-workers.
Scheme 51: Synthesis of menadione analogues functionalized with thiols.
Scheme 52: Synthesis of menadione-derived symmetrical derivatives through reaction with dithiols.
Scheme 53: Mercaptoalkyl acids as nucleophiles in Michael-type addition reaction to menadione.
Scheme 54: Reactions of menadione (10) with cysteine derivatives for the synthesis of quinoproteins.
Scheme 55: Synthesis of menadione-glutathione conjugate 152 by Michael-type addition.
Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197
Graphical Abstract
Figure 1: Molecular structures of emitters.
Figure 2: a) Molecular structure and b) optimized DFT-calculated geometry of DICzTRZ. Hydrogen atoms are omit...
Figure 3: HOMO, HOMO–1 (H–1), LUMO, and LUMO+1 (L+1) electron density distributions (isovalue: 0.02) and ener...
Figure 4: a) Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) of DICzTRZ in DCM (scan rate = ...
Figure 5: a) Prompt and b) delayed time-resolved decay in spin-coated 20 wt % CzSi film of DICzTRZ (λexc = 37...
Figure 6: Angle-resolved photoluminescence measurement of a solution-processed film of 20 wt % DICzTRZ in CzS...
Figure 7: Device characteristics of 20 and 30 wt % DICzTRZ-based OLEDs, which are represented by red and blue...
Figure 8: Device efficiency simulation of the fabricated OLEDs depicting the variation in EQE with varied PL ...
Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131
Graphical Abstract
Figure 1: Examples of anthracene derivatives and their applications.
Scheme 1: Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes.
Scheme 2: Rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal...
Scheme 3: Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes.
Scheme 4: [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt...
Scheme 5: Cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23).
Scheme 6: [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent.
Scheme 7: Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates.
Scheme 8: Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides.
Scheme 9: Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2.
Scheme 10: BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44.
Scheme 11: Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes a...
Scheme 12: Reduction of anthraquinones by using Zn/pyridine or Zn/NaOH reductive methods.
Scheme 13: Two-step route to novel substituted Indenoanthracenes.
Scheme 14: Synthesis of 1,8-diarylanthracenes through Suzuki–Miyaura coupling reaction in the presence of Pd-P...
Scheme 15: Synthesis of five new substituted anthracenes by using LAH as reducing agent.
Scheme 16: One-pot procedure to synthesize substituted 9,10-dicyanoanthracenes.
Scheme 17: Reduction of bromoanthraquinones with NaBH4 in alkaline medium.
Scheme 18: In(III)-catalyzed reductive-dehydration intramolecular cycloaromatization of 2-benzylic aromatic al...
Scheme 19: Acid-catalyzed cyclization of new O-protected ortho-acetal diarylmethanols.
Scheme 20: Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylme...
Scheme 21: BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmeth...
Scheme 22: Synthesis of 2,3,6,7-anthracenetetracarbonitrile (90) by double Wittig reaction followed by deprote...
Scheme 23: Homo-elongation protocol for the synthesis of substituted acene diesters/dinitriles.
Scheme 24: Synthesis of two new parental BN anthracenes via borylative cyclization.
Scheme 25: Synthesis of substituted anthracenes from a bifunctional organomagnesium alkoxide.
Scheme 26: Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates.
Scheme 27: Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates.
Scheme 28: Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives.
Scheme 29: AuCl-catalyzed double cyclization of diiodoethynylterphenyl compounds.
Scheme 30: Iodonium-induced electrophilic cyclization of terphenyl derivatives.
Scheme 31: Oxidative photocyclization of 1,3-distyrylbenzene derivatives.
Scheme 32: Oxidative cyclization of 2,3-diphenylnaphthalenes.
Scheme 33: Suzuki-Miyaura/isomerization/ring closing metathesis strategy to synthesize benz[a]anthracenes.
Scheme 34: Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives.
Scheme 35: Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent.
Scheme 36: Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl propiolates followed by intra...
Scheme 37: H3PO4-promoted intramolecular cyclization of substituted benzoic acids.
Scheme 38: Palladium-catalyzed intermolecular direct acylation of aromatic aldehydes and o-iodoesters.
Scheme 39: Cycloaddition/oxidative aromatization of quinone and β-enamino esters.
Scheme 40: ʟ-Proline-catalyzed [4 + 2] cycloaddition reaction of naphthoquinones and α,β-unsaturated aldehydes....
Scheme 41: Iridium-catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with alkynes.
Scheme 42: Synthesis of several anthraquinone derivatives by using InCl3 and molecular iodine.
Scheme 43: Indium-catalyzed multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (...
Scheme 44: Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system.
Scheme 45: Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones.
Scheme 46: [4 + 2] Anionic annulation reaction for the synthesis of substituted anthraquinones.
Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111
Graphical Abstract
Scheme 1: Representatives of isomeric bisoxindoles.
Scheme 2: Isoindigo-based OSCs with the best efficiency.
Scheme 3: Monoisoindigos with preferred 6,6'-substitution.
Scheme 4: Possibility of aromatic–quinoid structural transition.
Scheme 5: Isoindigo structures with incorporated acceptor nitrogen heterocycles.
Scheme 6: Monoisoindigos bearing pyrenyl substituents.
Scheme 7: p-Alkoxyphenylene-embedded thienylisoindigo with different acceptor anchor units.
Scheme 8: Nonfullerene OSC based on perylene diimide-derived isoindigo.
Scheme 9: Isoindigo as an additive in all-polymer OSCs.
Scheme 10: Bisisoindigos with different linker structures.
Scheme 11: Nonthiophene oligomeric monoisoindigos for OSCs.
Scheme 12: The simplest examples of polymers with a monothienylisoindigo monomeric unit.
Scheme 13: Monothienylisoindigos bearing π-extended electron-donor backbones.
Scheme 14: Role of fluorination and the molecular weight on OSC efficiency on the base of the bithiopheneisoin...
Scheme 15: Trithiopheneisoindigo polymers with variation in the substituent structure.
Scheme 16: Polymeric thienyl-linked bisisoindigos for OSCs.
Scheme 17: Isoindigo bearing the thieno[3,2-b]thiophene structural motif as donor component of OSCs.
Scheme 18: Thienylisoindigos with incorporated aromatic unit.
Scheme 19: One-component nonfullerene OSCs on the base of isoindigo.
Scheme 20: Isoindigo-based nonthiophene aza aromatic polymers as acceptor components of OSCs.
Scheme 21: Polymers with isoindigo substituent as side-chain photon trap.
Scheme 22: Isoindigo derivatives for OFET technology with the best mobility.
Scheme 23: Monoisoindigos as low-molecular-weight semiconductors.
Scheme 24: Polymeric bithiopheneisoindigos for OFET creation.
Scheme 25: Fluorination as a tool to improve isoindigo-based OFET devices.
Scheme 26: Diversely DPP–isoindigo-conjugated polymers for OFETs.
Scheme 27: Isoindigoid homopolymers with differing rigidity.
Scheme 28: Isoindigo-based materials with extended π-conjugation.
Scheme 29: Poly(isoindigothiophene) compounds as sensors for ammonia.
Scheme 30: Sensor devices based on poly(isoindigoaryl) compounds.
Scheme 31: Isoindigo polymers for miscellaneous applications.
Scheme 32: Mono-, rod-like, and polymeric isoindigos as agents for photoacoustic and photothermal cancer thera...
Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86
Graphical Abstract
Scheme 1: General strategy for the enantioselective synthesis of N-containing heterocycles from N-tert-butane...
Scheme 2: Methodologies for condensation of aldehydes and ketones with tert-butanesulfinamides (1).
Scheme 3: Transition models for cis-aziridines and trans-aziridines.
Scheme 4: Mechanism for the reduction of N-tert-butanesulfinyl imines.
Scheme 5: Transition models for the addition of organomagnesium and organolithium compounds to N-tert-butanes...
Scheme 6: Synthesis of 2,2-dibromoaziridines 15 from aldimines 14 and bromoform, and proposed non-chelation-c...
Scheme 7: Diastereoselective synthesis of aziridines from tert-butanesulfinyl imines.
Scheme 8: Synthesis of vinylaziridines 22 from aldimines 14 and 1,3-dibromopropene 23, and proposed chelation...
Scheme 9: Synthesis of vinylaziridines 27 from aldimines 14 and α-bromoesters 26, and proposed transition sta...
Scheme 10: Synthesis of 2-chloroaziridines 28 from aldimines 14 and dichloromethane, and proposed transition s...
Scheme 11: Synthesis of cis-vinylaziridines 30 and 31 from aldimines 14 and bromomethylbutenolide 29.
Scheme 12: Synthesis of 2-chloro-2-aroylaziridines 36 and 32 from aldimines 14, arylnitriles 34, and silyldich...
Scheme 13: Synthesis of trifluoromethylaziridines 39 and proposed transition state of the aziridination.
Scheme 14: Synthesis of aziridines 42 and proposed state transition.
Scheme 15: Synthesis of 1-substituted 2-azaspiro[3.3]heptanes, 1-phenyl-2-azaspiro[3.4]octane and 1-phenyl-2-a...
Scheme 16: Synthesis of 1-substituted 2,6-diazaspiro[3.3]heptanes 48 from chiral imines 14 and 1-Boc-azetidine...
Scheme 17: Synthesis of β-lactams 52 from chiral imines 14 and dimethyl malonate (49).
Scheme 18: Synthesis of spiro-β-lactam 57 from chiral (RS)-N-tert-butanesulfinyl isatin ketimine 53 and ethyl ...
Scheme 19: Synthesis of β-lactam 60, a precursor of (−)-batzelladine D (61) and (−)-13-epi-batzelladine D (62)...
Scheme 20: Rhodium-catalyzed asymmetric synthesis of 3-substituted pyrrolidines 66 from chiral imine (RS)-63 a...
Scheme 21: Asymmetric synthesis of 1,3-disubstituted isoindolines 69 and 70 from chiral imine 67.
Scheme 22: Asymmetric synthesis of cis-2,5-disubstituted pyrrolidines 73 from chiral imine (RS)-71.
Scheme 23: Asymmetric synthesis of 3-hydroxy-5-substituted pyrrolidin-2-ones 77 from chiral imine (RS)-74.
Scheme 24: Asymmetric synthesis of 4-hydroxy-5-substituted pyrrolidin-2-ones 80 from chiral imines 79.
Scheme 25: Asymmetric synthesis of 3-pyrrolines 82 from chiral imines 14 and ethyl 4-bromocrotonate (81).
Scheme 26: Asymmetric synthesis of γ-amino esters 84, and tetramic acid derivative 86 from chiral imines (RS)-...
Scheme 27: Asymmetric synthesis of α-methylene-γ-butyrolactams 90 from chiral imines (Z,SS)-87 and ethyl 2-bro...
Scheme 28: Asymmetric synthesis of methylenepyrrolidines 92 from chiral imines (RS)-14 and 2-(trimethysilylmet...
Scheme 29: Synthesis of dibenzoazaspirodecanes from cyclic N-tert-butanesulfinyl imines.
Scheme 30: Stereoselective synthesis of cyclopenta[c]proline derivatives 103 from β,γ-unsaturated α-amino acid...
Scheme 31: Stereoselective synthesis of alkaloids (−)-angustureine (107) and (−)-cuspareine (108).
Scheme 32: Stereoselective synthesis of alkaloids (−)-pelletierine (112) and (+)-coniine (117).
Scheme 33: Synthesis of piperidine alkaloids (+)-dihydropinidine (122a), (+)-isosolenopsin (122b) and (+)-isos...
Scheme 34: Stereoselective synthesis of the alkaloids(+)-sedamine (125) from chiral imine (SS)-119.
Scheme 35: Stereoselective synthesis of trans-5-hydroxy-6-substituted-2-piperidinones 127 and 129 from chiral ...
Scheme 36: Stereoselective synthesis of trans-5-hydroxy-6-substituted ethanone-2-piperidinones 132 from chiral...
Scheme 37: Stereoselective synthesis of trans-3-benzyl-5-hydroxy-6-substituted-2-piperidinones 136 from chiral...
Scheme 38: Stereoselective synthesis of trans-5-hydroxy-6-substituted 2-piperidinones 139 from chiral imine 138...
Scheme 39: Stereoselective synthesis of ʟ-hydroxypipecolic acid 145 from chiral imine 144.
Scheme 40: Synthesis of 1-substituted isoquinolones 147, 149 and 151.
Scheme 41: Stereoselective synthesis of 3-substituted dihydrobenzo[de]isoquinolinones 154.
Scheme 42: Enantioselective synthesis of alkaloids (S)-1-benzyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (...
Scheme 43: Enantioselective synthesis of alkaloids (−)-cermizine B (171) and (+)-serratezomine E (172) develop...
Scheme 44: Stereoselective synthesis of (+)-isosolepnosin (177) and (+)-solepnosin (178) from homoallylamine d...
Scheme 45: Stereoselective synthesis of tetrahydroquinoline derivatives 184, 185 and 187 from chiral imines (RS...
Scheme 46: Stereoselective synthesis of pyridobenzofuran and pyridoindole derivatives 193 from homopropargylam...
Scheme 47: Stereoselective synthesis of 2-substituted 1,2,5,6-tetrahydropyridines 196 from chiral imines (RS)-...
Scheme 48: Stereoselective synthesis of 2-substituted trans-2,6-disubstituted piperidine 199 from chiral imine...
Scheme 49: Stereoselective synthesis of cis-2,6-disubstituted piperidines 200, and alkaloid (+)-241D, from chi...
Scheme 50: Stereoselective synthesis of 6-substituted piperidines-2,5-diones 206 and 1,7-diazaspiro[4.5]decane...
Scheme 51: Stereoselective synthesis of spirocyclic oxindoles 210 from chiral imines (RS)-53.
Scheme 52: Stereoselective synthesis of azaspiro compound 213 from chiral imine 211.
Scheme 53: Stereoselective synthesis of tetrahydroisoquinoline derivatives from chiral imines (RS)-214.
Scheme 54: Stereoselective synthesis of (−)-crispine A 223 from chiral imine (RS)-214.
Scheme 55: Synthesis of (−)-harmicine (228) using tert-butanesulfinamide through haloamide cyclization.
Scheme 56: Stereoselective synthesis of tetraponerines T1–T8.
Scheme 57: Stereoselective synthesis of phenanthroindolizidines 246a and (−)-tylophorine (246b), and phenanthr...
Scheme 58: Stereoselective synthesis of indoline, tetrahydroquinoline and tetrahydrobenzazepine derivatives 253...
Scheme 59: Stereoselective synthesis of (+)-epohelmin A (258) and (+)-epohelmin B (260) from aldimine (RS)-79.
Scheme 60: Stereoselective synthesis of (−)-epiquinamide (266) from chiral aldimine (SS)-261.
Scheme 61: Synthesis synthesis of (–)-hippodamine (273) and (+)-epi-hippodamine (272) using chiral sulfinyl am...
Scheme 62: Stereoselective synthesis of (+)-grandisine D (279) and (+)-amabiline (283).
Scheme 63: Stereoselective synthesis of (−)-epiquinamide (266) and (+)-swaisonine (291) from aldimine (SS)-126....
Scheme 64: Stereoselective synthesis of (+)-C(9a)-epi-epiquinamide (294).
Scheme 65: Stereoselective synthesis of (+)-lasubine II (298) from chiral aldimine (SS)-109.
Scheme 66: Stereoselective synthesis of (−)-epimyrtine (300a) and (−)-lasubine II (ent-302) from β-amino keton...
Scheme 67: Stereoselective synthesis of (−)-tabersonine (310), (−)-vincadifformine (311), and (−)-aspidospermi...
Scheme 68: Stereoselective synthesis of (+)-epohelmin A (258) and (+)-epohelmin B (260) from aldehyde 313 and ...
Scheme 69: Total synthesis of (+)-lysergic acid (323) from N-tert-butanesulfinamide (RS)-1.
Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77
Graphical Abstract
Scheme 1: General strategy for the synthesis of THPs.
Scheme 2: Developments towards the Prins cyclization.
Scheme 3: General stereochemical outcome of the Prins cyclization.
Scheme 4: Regioselectivity in the Prins cyclization.
Scheme 5: Mechanism of the oxonia-Cope reaction in the Prins cyclization.
Scheme 6: Cyclization of electron-deficient enantioenriched alcohol 27.
Scheme 7: Partial racemization through 2-oxonia-Cope allyl transfer.
Scheme 8: Partial racemization by reversible 2-oxonia-Cope rearrangement.
Scheme 9: Rychnovsky modification of the Prins cyclization.
Scheme 10: Synthesis of (−)-centrolobine and the C22–C26 unit of phorboxazole A.
Scheme 11: Axially selective Prins cyclization by Rychnovsky et al.
Scheme 12: Mechanism for the axially selectivity Prins cyclization.
Scheme 13: Mukaiyama aldol–Prins cyclization reaction.
Scheme 14: Application of the aldol–Prins reaction.
Scheme 15: Hart and Bennet's acid-promoted Prins cyclization.
Scheme 16: Tetrahydropyran core of polycarvernoside A as well as (−)-clavoslide A and D.
Scheme 17: Scheidt and co-workers’ route to tetrahydropyran-4-one.
Scheme 18: Mechanism for the Lewis acid-catalyzed synthesis of tetrahydropyran-4-one.
Scheme 19: Hoveyda and co-workers’ strategy for 2,6-disubstituted 4-methylenetetrahydropyran.
Scheme 20: Funk and Cossey’s ene-carbamates strategy.
Scheme 21: Yadav and Kumar’s cyclopropane strategy for THP synthesis.
Scheme 22: 2-Arylcylopropylmethanolin in centrolobine synthesis.
Scheme 23: Yadav and co-workers’ strategy for the synthesis of THP.
Scheme 24: Yadav and co-workers’ Prins–Ritter reaction sequence for 4-amidotetrahydropyran.
Scheme 25: Yadav and co-workers’ strategy to prelactones B, C, and V.
Scheme 26: Yadav and co-workers’ strategy for the synthesis of (±)-centrolobine.
Scheme 27: Loh and co-workers’ strategy for the synthesis of zampanolide and dactylolide.
Scheme 28: Loh and Chan’s strategy for THP synthesis.
Scheme 29: Prins cyclization of cyclohexanecarboxaldehyde.
Scheme 30: Prins cyclization of methyl ricinoleate (127) and benzaldehyde (88).
Scheme 31: AlCl3-catalyzed cyclization of homoallylic alcohol 129 and aldehyde 130.
Scheme 32: Martín and co-workers’ stereoselective approach for the synthesis of highly substituted tetrahydrop...
Scheme 33: Ene-IMSC strategy by Marko and Leroy for the synthesis of tetrahydropyran.
Scheme 34: Marko and Leroy’s strategy for the synthesis of tetrahydropyrans 146.
Scheme 35: Sakurai dimerization/macrolactonization reaction for the synthesis of cyanolide A.
Scheme 36: Hoye and Hu’s synthesis of (−)-dactyloide by intramolecular Sakurai cyclization.
Scheme 37: Minehan and co-workers’ strategy for the synthesis of THPs 157.
Scheme 38: Yu and co-workers’ allylic transfer strategy for the construction of tetrahydropyran 161.
Scheme 39: Reactivity enhancement in intramolecular Prins cyclization.
Scheme 40: Floreancig and co-workers’ Prins cyclization strategy to (+)-dactyloide.
Scheme 41: Panek and Huang’s DHP synthesis from crotylsilanes: a general strategy.
Scheme 42: Panek and Huang’s DHP synthesis from syn-crotylsilanes.
Scheme 43: Panek and Huang’s DHP synthesis from anti-crotylsilanes.
Scheme 44: Roush and co-workers’ [4 + 2]-annulation strategy for DHP synthesis [82].
Scheme 45: TMSOTf-promoted annulation reaction.
Scheme 46: Dobb and co-workers’ synthesis of DHP.
Scheme 47: BiBr3-promoted tandem silyl-Prins reaction by Hinkle et al.
Scheme 48: Substrate scope of Hinkle and co-workers’ strategy.
Scheme 49: Cho and co-workers’ strategy for 2,6 disubstituted 3,4-dimethylene-THP.
Scheme 50: Furman and co-workers’ THP synthesis from propargylsilane.
Scheme 51: THP synthesis from silyl enol ethers.
Scheme 52: Rychnovsky and co-workers’ strategy for THP synthesis from hydroxy-substituted silyl enol ethers.
Scheme 53: Li and co-workers’ germinal bissilyl Prins cyclization strategy to (−)-exiguolide.
Scheme 54: Xu and co-workers’ hydroiodination strategy for THP.
Scheme 55: Wang and co-workers’ strategy for tetrahydropyran synthesis.
Scheme 56: FeCl3-catalyzed synthesis of DHP from alkynylsilane alcohol.
Scheme 57: Martín, Padrón, and co-workers’ proposed mechanism of alkynylsilane Prins cyclization for the synth...
Scheme 58: Marko and co-workers’ synthesis of 2,6-anti-configured tetrahydropyran.
Scheme 59: Loh and co-workers’ strategy for 2,6-syn-tetrahydropyrans.
Scheme 60: Loh and co-workers’ strategy for anti-THP synthesis.
Scheme 61: Cha and co-workers’ strategy for trans-2,6-tetrahydropyran.
Scheme 62: Mechanism proposed by Cha et al.
Scheme 63: TiCl4-mediated cyclization to trans-THP.
Scheme 64: Feng and co-workers’ FeCl3-catalyzed Prins cyclization strategy to 4-hydroxy-substituted THP.
Scheme 65: Selectivity profile of the Prins cyclization under participation of an iron ligand.
Scheme 66: Sequential reactions involving Prins cyclization.
Scheme 67: Banerjee and co-workers’ strategy of Prins cyclization from cyclopropane carbaldehydes and propargy...
Scheme 68: Mullen and Gagné's (R)-[(tolBINAP)Pt(NC6F5)2][SbF6]2-catalyzed asymmetric Prins cyclization strateg...
Scheme 69: Yu and co-workers’ DDQ-catalyzed asymmetric Prins cyclization strategy to trisubstituted THPs.
Scheme 70: Lalli and Weghe’s chiral-Brønsted-acid- and achiral-Lewis-acid-promoted asymmetric Prins cyclizatio...
Scheme 71: List and co-workers’ iIDP Brønsted acid-promoted asymmetric Prins cyclization strategy.
Scheme 72: Zhou and co-workers’ strategy for chiral phosphoric acid (CPA)-catalyzed cascade Prins cyclization.
Scheme 73: List and co-workers’ approach for asymmetric Prins cyclization using chiral imidodiphosphoric acid ...
Beilstein J. Org. Chem. 2019, 15, 2458–2464, doi:10.3762/bjoc.15.238
Graphical Abstract
Scheme 1: Indium-mediated allylation of melibiose (1).
Scheme 2: Diastereomeric ratio of allylation; R = per-O-Ac-α-Gal.
Figure 1: X-ray analysis of the main C-allylation product 2-syn [CCDC 1922520].
Scheme 3: Reaction scheme of the ozonolysis sequence.
Scheme 4: Ozonolysis sequence for the syn-product.
Figure 2: Structures of the main products 5-syn-β and 5-anti-β.
Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194
Graphical Abstract
Figure 1: Structures of triptolide (1), triptonide (2), tripdiolide (3), 16-hydroxytriptolide (4), triptrioli...
Figure 2: Syntheses of triptolide.
Scheme 1: Berchtold’s synthesis of triptolide.
Scheme 2: Li’s formal synthesis of triptolide.
Scheme 3: van Tamelen’s asymmetric synthesis of triptonide and triptolide.
Scheme 4: Van Tamelen’s (method II) formal synthesis of triptolide.
Scheme 5: Sherburn’s formal synthesis of triptolide.
Scheme 6: van Tamelen’s biogenetic type total synthesis of triptolide.
Scheme 7: Yang’s total synthesis of triptolide.
Scheme 8: Key intermediates or transformations of routes J–N.
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
Beilstein J. Org. Chem. 2019, 15, 1304–1312, doi:10.3762/bjoc.15.129
Graphical Abstract
Scheme 1: Asymmetric carbocation catalysis.
Scheme 2: Synthesis of new carbocation catalysts with weakly coordinating metal-based phosphate anion.
Figure 1: Dissociation of latent carbocation by the use of Lewis acids. a) UV–vis absorption spectra of TP (0...
Scheme 3: a) The reaction with 9,10-dimethylanthracene (3b). b) Gram-scale reaction of 3a and 4k, and transfo...
Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104
Graphical Abstract
Figure 1: γ-Lactam-derived structures considered in this review.
Figure 2: Alkaloids containing an isoindolinone moiety.
Figure 3: Alkaloids containing the 2-oxindole ring system.
Figure 4: Drugs and biological active compounds containing an isoindolinone moiety.
Figure 5: Drugs and biologically active compounds bearing a 2-oxindole skeleton.
Scheme 1: Three-component reaction of benzoic acid 1, amides 2 and DMSO (3).
Scheme 2: Copper-catalysed three-component reaction of 2-iodobenzoic acids 10, alkynylcarboxylic acids 11 and...
Scheme 3: Proposed mechanism for the formation of methylene isoindolinones 13.
Scheme 4: Copper-catalysed three-component reaction of 2-iodobenzamide 17, terminal alkyne 18 and pyrrole or ...
Scheme 5: Palladium-catalysed three-component reaction of ethynylbenzamides 21, secondary amines 22 and CO (23...
Scheme 6: Proposed mechanism for the formation of methyleneisoindolinones 24.
Scheme 7: Copper-catalysed three-component reaction of formyl benzoate 29, amines 2 and alkynes 18.
Scheme 8: Copper-catalysed three-component reaction of formylbenzoate 29, amines 2 and ketones 31.
Scheme 9: Non-catalysed (A) and phase-transfer catalysed (B) three-component reactions of formylbenzoic acids ...
Scheme 10: Proposed mechanism for the formation of isoindolinones 36.
Scheme 11: Three-component reaction of formylbenzoic acid 33, amines 2 and fluorinated silyl ethers 39.
Scheme 12: Three-component Ugi reaction of 2-formylbenzoic acid (33), diamines 41 and isocyanides 42.
Scheme 13: Non-catalysed (A, B) and chiral phosphoric acid promoted (C) three-component Ugi reactions of formy...
Scheme 14: Proposed mechanism for the enantioselective formation of isoindolinones 46.
Scheme 15: Three-component reaction of benzoic acids 33 or 54, amines 2 and TMSCN (52).
Scheme 16: Several variations of the three-component reaction of formylbenzoic acids 33, amines 2 and isatoic ...
Scheme 17: Proposed mechanism for the synthesis of isoindoloquinazolinones 57.
Scheme 18: Three-component reaction of isobenzofuranone 61, amines 2 and isatoic anhydrides 56.
Scheme 19: Palladium-catalysed three-component reaction of 2-aminobenzamides 59, 2-bromobenzaldehydes 62 and C...
Scheme 20: Proposed mechanism for the palladium-catalysed synthesis of isoindoloquinazolinones 57.
Scheme 21: Four-component reaction of 2-vinylbenzoic acids 67, aryldioazonium tetrafluoroborates 68, DABCO·(SO2...
Scheme 22: Plausible mechanism for the formation of isoindolinones 71.
Scheme 23: Three-component reaction of trimethylsilylaryltriflates 77, isocyanides 42 and CO2 (78).
Scheme 24: Plausible mechanism for the three-component synthesis of phthalimides 79.
Scheme 25: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, arenes 86 and diaryliodonium...
Scheme 26: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, diaryliodonium salts 87 and ...
Scheme 27: Proposed mechanism for the formation of 2,3-diarylisoindolinones 88, 89 and 92.
Scheme 28: Palladium-catalysed three-component reaction of chloroquinolinecarbaldehydes 97 with isocyanides 42...
Scheme 29: Palladium-catalysed three-component reaction of imines 99 with CO (23) and ortho-iodoarylimines 100....
Scheme 30: Palladium-catalysed three-component reaction of amines 2 with CO (23) and aryl iodide 105.
Scheme 31: Three-component reaction of 2-ethynylanilines 109, perfluoroalkyl iodides 110 and carbon monoxide (...
Scheme 32: Ultraviolet-induced three-component reaction of N-(2-iodoaryl)acrylamides 113, DABCO·(SO2)2 (69) an...
Scheme 33: Proposed mechanism for the preparation of oxindoles 115.
Scheme 34: Three-component reaction of acrylamide 113, CO (23) and 1,4-benzodiazepine 121.
Scheme 35: Multicomponent reaction of sulfonylacrylamides 123, aryldiazonium tetrafluoroborates 68 and DABCO·(...
Scheme 36: Proposed mechanism for the preparation of oxindoles 124.
Scheme 37: Three-component reaction of N-arylpropiolamides 128, aryl iodides 129 and boronic acids 130.
Scheme 38: Proposed mechanism for the formation of diarylmethylene- and diarylallylideneoxindoles 131 and 132.
Scheme 39: Three-component reaction of cyclohexa-1,3-dione (136), amines 2 and alkyl acetylenedicarboxylates 1...
Scheme 40: Proposed mechanism for the formation of 2-oxindoles 138.
Beilstein J. Org. Chem. 2019, 15, 733–745, doi:10.3762/bjoc.15.69
Graphical Abstract
Figure 1: Absorption spectra in the UV and visible spectral region: 1) bis(cyclopentadienyl)titan dichloride (...
Figure 2: Absorption spectra in the visible spectral region: 1) Cp2TiCl2·AlEt2Cl (toluene, 10 mmol/L, Ti/Al r...
Figure 3: 1Н NMR spectra of tricyclopentadiene (a) and the interaction product between Cp2TiCl2 and AlEt2Cl w...
Scheme 1: Mechanism of alkylation of Cp2TiCl2.
Figure 4: Visible spectra of a mixture of Cp2TiCl2 and AlEt2Cl as function of time.
Figure 5: Thermometric curve of DCPD polymerization using the catalyst system based on Cp2TiCl2 (a) and its s...
Scheme 2: The structures formed as a result of the cationic polymerization of dicyclopentadiene.
Scheme 3: The units resulting from ROMP of dicyclopentadiene.
Scheme 4: Mechanism of ROMP dicyclopentadiene.
Figure 6: FTIR spectrum of PDCPD obtained in toluene with the catalyst system based on Cp2TiCl2 and AlEt2Cl.
Figure 7: 1Н NMR spectrum of PDCPD obtained with the catalytic system based on Cp2TiCl2 and AlEt2Cl.
Figure 8: GPC traces for two samples of DCPD polymers obtained at a concentration of Cp2TiCl2/AlEt2Cl complex...
Figure 9: IR spectra of cationic polymerized dicyclopentadiene taken after certain periods of time exposed to...
Figure 10: Correlation of intensities of vibrational bands at 1620 and 700 cm−1 and layer exposure time in air...
Figure 11: DSC exotherm for PDCPD subjected to air oxidation for 700 hours.
Figure 12: DSC exotherm for PDCPD subjected to unexposed film: 1) in air atmosphere; 2) in argon.
Scheme 5: Possible radical formation in the reaction (1).
Scheme 6: The first step of the chain propagation.
Figure 13: Dependence of intensities of adsorption bands at 1410 and 700 cm−1 and dwell time of the layer in a...
Figure 14: Semi-logarithmic kinetic curve of PDCPD oxidation in air (thin layer on silicon) with respect to in...
Figure 15: The distribution of oxygen concentration in the polymer layer: 1 – a layer of oxidized cross-linked...
Figure 16: Dependence of the ratio of adsorption bands at 1700 and 700 cm−1 on the exposure time of the layer ...
Figure 17: Infrared spectra (a) of products of cationic polymerization of DCPD, stabilized with an antioxidant...
Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34
Graphical Abstract
Figure 1: Selected examples of valuable β-ketosulfides. A: bioactive synthetic compounds, B: natural products....
Scheme 1: Different strategies for the preparation of β-ketosulfides.
Scheme 2: Thiol-free chemoenzymatic synthesis of β-ketosulfides.
Figure 2: Time-course plot for the CAL-B catalysed hydrolysis of 1a.
Scheme 3: One-pot two-step preparation of phenacylalkylsulfides. aReaction conditions: i. α-haloketone (0.25 ...
Scheme 4: Selective oxidation of the β-ketosulfide 2a.
Beilstein J. Org. Chem. 2018, 14, 2846–2852, doi:10.3762/bjoc.14.263
Graphical Abstract
Scheme 1: α-Amino esters from ethyl nitroacetate (4).
Scheme 2: Preparations of α-amino esters 10, 12 and 14.
Scheme 3: Syntheses of α-amino ester 18 and piperazinediones 23a,b.
Scheme 4: Syntheses of α-hydroximino ester 29 and α-amino ester 36.
Scheme 5: Synthesis of α-amino ester 43.