Search for "dye" in Full Text gives 266 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56
Graphical Abstract
Figure 1: Structure-guided approach for engineering the (non-covalent) fluorescent light-up aptamer Pepper in...
Scheme 1: Chemical structures of the HBC dye family [7]. Variations to HBC530 highlighted in red color. All dyes...
Scheme 2: Synthesis of bromoalkyl HBC derivatives 7, 8, and 9.
Scheme 3: Synthesis of the HBC ether derivative 11.
Figure 2: Pepper aptamer reacts with different HBC derivatives. Chemical structures of the HBC derivatives us...
Scheme 4: Derivatization of the HBC fluorophore 5 to generate handles with distinct electrophilic groups.
Scheme 5: Synthesis of mesylated HBC fluorophores 16, 17, and 18.
Scheme 6: Synthesis of the bifunctional HBC fluorophore 22. For an application of 22 (pulldown of circular Pe...
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, 358–368, doi:10.3762/bjoc.21.26
Graphical Abstract
Scheme 1: Synthesis of 2-hetaryl-substituted 1,3-tropolones 1.
Scheme 2: Synthesis of 1,3-tropolones 7a,b and 8a,b. Reagents and conditions: method A: dioxane, reflux; meth...
Figure 1: Structural characteristics of (NH) and (OH) tautomeric forms of compounds 7 and 8 in the gas phase ...
Figure 2: Scheme of HMBC correlations of compound 7a in DMSO-d6.
Figure 3: Molecular structure of 2-(3,3-dimethyl-3H-benzo[g]indolin-2-yl)-5,6,7-trichloro-1,3-tropolone (7b).
Figure 4: Result of matching structures of 7b (solid lines) and 2-(3,3-dimethylindolin-2-yl)-5,6,7-trichloro-...
Figure 5: Absorption and emission spectra of compound 8b in acetonitrile before (1,1’) (c 2.5 × 10−5 mol L–1)...
Scheme 3: Possible binding mode of 7 and 8 with CN− and F−.
Figure 6: Dose–response curves for H1299 and A431 cells treated with compound 7a for 24 h. *Significant diffe...
Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22
Graphical Abstract
Figure 1: Influence of the metal center M (Fe, Ru, Os) on the position of the MLCT and MC (metal-centered) ab...
Scheme 1: Red-light-mediated ring-closing metathesis through activation of a ruthenium catalyst by an osmium ...
Scheme 2: Photocatalyzed polymerization of dicylopentadiene mediated with red or blue light.
Figure 2: Comparison between [Ru(bpy)3]2+ and [Os(tpy)2]2+ in a photocatalyzed trifluoromethylation reaction:...
Scheme 3: Red-light photocatalyzed C–N cross-coupling reaction by T. Rovis et al. (SET = single-electron tran...
Figure 3: Red-light-mediated aryl oxidative addition with a bismuthinidene complex.
Scheme 4: Red-light-mediated reduction of aryl derivatives by O. S. Wenger et al. (PC = photocatalyst, anh = ...
Scheme 5: Red-light-mediated aryl halides reduction with an isoelectronic chromium complex (TDAE = tetrakis(d...
Scheme 6: Red-light-photocatalyzed trifluoromethylation of styrene derivatives with Umemoto’s reagent and a p...
Scheme 7: Red-light-mediated energy transfer for the cross-dehydrogenative coupling of N-phenyltetrahydroisoq...
Scheme 8: Red-light-mediated oxidative cyanation of tertiary amines with a phthalocyanin zinc complex.
Scheme 9: Formation of dialins and tetralins via a red-light-photocatalyzed reductive decarboxylation mediate...
Scheme 10: Oxidation of β-citronellol (28) via energy transfer mediated by a red-light activable silicon phtha...
Scheme 11: Formation of alcohol derivatives 32 from boron compounds 31 using chlorophyll (chl) as a red-light-...
Scheme 12: Red-light-driven reductive dehalogenation of α-halo ketones mediated by a thiaporphyrin photocataly...
Figure 4: Photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization medi...
Figure 5: Recent examples of red-light-mediated photocatalytic reactions with traditional organic dyes.
Figure 6: Squaraine photocatalysts used by Goddard et al. and aza-Henry reaction with squaraine-based photoca...
Figure 7: Reactions described by Goddard et al. involving 40 as the photocatalyst.
Figure 8: Various structures of squaraine derivatives used to initiate photopolymerizations.
Figure 9: Naturally occurring cyanins.
Figure 10: Influence of the structure on the photophysical properties of a cyanin dye.
Figure 11: NIR-light-mediated aza-Henry reaction photocatalyzed by 46.
Scheme 13: Photocatalyzed arylboronic acids oxidation by 46.
Figure 12: Cyanin structures synthetized and characterized by Goddard et al. (redox potentials given against s...
Figure 13: N,N′-Di-n-propyl-1,13-dimethoxyquinacridinium (55) with its redox potentials at its ground state an...
Scheme 14: Dual catalyzed C(sp2)–H arylation of 57 using DMQA 55 as the red-light-absorbing photocatalyst.
Scheme 15: Red-light-mediated aerobic oxidation of arylboronic acids 59 into phenols 60 via the use of DMQA as...
Figure 14: Red-light-photocatalyzed reactions proposed by Gianetti et al. using DMQA as the photocatalyst.
Scheme 16: Simultaneous release of NO and production of superoxide (O2•−) and their combination yielding the p...
Figure 15: Palladium porphyrin complex as the photoredox catalyst and the NO releasing substrate are linked in...
Scheme 17: Uncaging of compound 69 which is a microtubule depolymerizing agent using near IR irradiation. The ...
Scheme 18: Photochemical uncaging of drugs protected with a phenylboronic acid derivative using near IR irradi...
Scheme 19: Photoredox catalytical generation of aminyl radicals with near IR irradiation for the transfer of b...
Scheme 20: Photoredox catalytical fluoroalkylation of tryptophan moieties.
Figure 16: Simultaneous absorption of two photons of infrared light of low energy enables electronic excitatio...
Scheme 21: Uncaging Ca2+ ions using two-photon excitation with near infrared light.
Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11
Graphical Abstract
Figure 1: Examples of solid state structures exhibiting CF2H group-mediated hydrogen bond interactions [16,18,21]. Hydr...
Figure 2: Hydrogen bond donors investigated in this study. For all cationic species, the counteranion is BF4−...
Figure 3: Hydrogen bond donation ability determined by UV–vis spectroscopy titration. A) Formation of HB comp...
Figure 4: A) HB complex formation between a donor and tri-n-butylphosphine oxide. B) 1H NMR spectra of 2b (5....
Figure 5: Hydrogen bond donation ability of various donors as quantified by the dissociation constant (Kd) of...
Figure 6: A) Linear correlation between ΔGexp and ΔGcalc. ΔGexp and ΔGcalc values are shown in Figure 5. B) Linear co...
Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261
Graphical Abstract
Figure 1: Classical MCRs.
Figure 2: Different scaffolds that can be formed with the Ugi adduct.
Scheme 1: Oxoindole-β-lactam core produced in a U4C-3CR.
Figure 3: Most active oxoindole-β-lactam compounds developed by Brãndao et al. [33].
Scheme 2: Ugi-azide synthesis of benzofuran, pyrazole and tetrazole hybrids.
Figure 4: The most promising hybrids synthesized via the Ugi-azide multicomponent reaction reported by Kushwa...
Scheme 3: Four-component Ugi reaction for the synthesis of novel antioxidant compounds.
Figure 5: Most potent antioxidant compounds obtained through the Ugi four-component reaction developed by Pac...
Scheme 4: Four-component Ugi reaction to synthesize β-amiloyd aggregation inhibitors.
Figure 6: The most potential β-amiloyd aggregation inhibitors generated by Galante et al. [37].
Scheme 5: Four-component Ugi reaction to obtain FATH hybrids and the best candidate synthesized.
Scheme 6: Four-component Ugi reaction for the synthesis of FATMH hybrids and the best candidate synthesized.
Scheme 7: Petasis multicomponent reaction to produce pyrazine-based MTDLs.
Figure 7: Best pyrazine-based MTDLs synthesized by Madhav et al. [40].
Scheme 8: Synthesis of BCPOs employing a Knoevenagel-based multicomponent reaction and the best candidate syn...
Scheme 9: Hantzsch multicomponent reaction for the synthesis of DHPs as novel MTDLs.
Figure 8: Most active 1,4-dihydropyridines developed by Malek et al. [43].
Scheme 10: Chromone–donepezil hybrid MTDLs obtained via the Passerini reaction.
Figure 9: Best CDH-based MTDLs as AChE inhibitors synthesized by Malek et al. [46].
Scheme 11: Replacement of the nitrogen in lactams 11 with an oxygen in 12 to influence hydrogen-bond donating ...
Scheme 12: MCR 3 + 2 reaction to develop spirooxindole, spiroacenaphthylene, and bisbenzo[b]pyran compounds.
Figure 10: SIRT2 activity of best derivatives obtained by Hasaninejad et al. [49].
Scheme 13: Synthesis of ML192 analogs using the Gewald multicomponent reaction and the best candidate synthesi...
Scheme 14: Development of 1,5-benzodiazepines via Ugi/deprotection/cyclization (UDC) approach by Xu et al. [59].
Scheme 15: Synthesis of polysubstituted 1,4-benzodiazepin-3-ones using UDC strategy.
Scheme 16: Synthetic procedure to obtain 3-carboxamide-1,4-benzodiazepin-5-ones employing Ugi–reduction–cycliz...
Scheme 17: Ugi cross-coupling (U-4CRs) to synthesize triazolobenzodiazepines.
Scheme 18: Azido-Ugi four component reaction cyclization to obtain imidazotetrazolodiazepinones.
Scheme 19: Synthesis of oxazolo- and thiazolo[1,4]benzodiazepine-2,5-diones via Ugi/deprotection/cyclization a...
Scheme 20: General synthesis of 2,3-dichlorophenylpiperazine-derived compounds by the Ugi reaction and Ugi/dep...
Figure 11: Best DRD2 compounds synthesized using a multicomponent strategy.
Scheme 21: Bucherer–Bergs multicomponent reaction to obtain a key intermediate in the synthesis of pomaglumeta...
Scheme 22: Ugi reaction to synthesize racetam derivatives and example of two racetams synthesized by Cioc et a...
Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257
Graphical Abstract
Figure 1: Chemical structures of the main tetrapyrrolic macrocycles studied in this review for their role as ...
Figure 2: Calix[4]pyrroles 3 and 4 and an their acyclic analogue 5 used for the transformation of Danishefsky...
Figure 3: Calixpyrrole-based organocatalysts 11 and 12 for the diastereoselective addition reaction of TMSOF ...
Figure 4: (a) Chemical structures of macrocyclic organocatalysts used for the synthesis of cyclic carbonates ...
Figure 5: Cuprous chloride-catalyzed aziridination of styrene (22) by chloramine-T (23) providing 1-tosyl-2-p...
Figure 6: Chemical structures of the various porphyrin macrocycles (18, 25–41) screened as potential catalyst...
Figure 7: Organocatalytic activity of distorted porphyrins explored by Senge and co-workers. Planar macrocycl...
Figure 8: Chemical structures of H2EtxTPP (x = 0, 2, 4, 6, 8) compounds with incrementally increasing nonplan...
Figure 9: Chemical structures of OxP macrocycles tested as potential organocatalysts for the conjugate additi...
Figure 10: a) Fundamental structure of the J-aggregates of diprotonated TPPS3 53 and b) its use as a catalyst ...
Figure 11: Chemical structures of amphiphilic porphyrin macrocycles used as pH-switchable catalysts based on i...
Figure 12: a) Chemical structures of porphyrin macrocycles for the cycloaddition of CO2 to N-alkyl/arylaziridi...
Figure 13: Electron and energy-transfer processes typical for excited porphyrin molecules (Por = porphyrin mac...
Figure 14: Proposed mechanism for the light-induced α-alkylation of aldehydes with EDA in the presence of H2TP...
Figure 15: a) Chemical structures of porphyrins screened as photoredox catalysts, b) model reaction of furan (...
Figure 16: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoreductants for the red light-induced C–H aryla...
Figure 17: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoredox catalyst for (a) α-alkylation of an alde...
Figure 18: Corrole macrocycles 98–100 as photoredox catalysts for C–H arylation and borylation reactions. Adap...
Figure 19: Proposed catalytic cycle of electrocatalytic generation of H2 evolution using tetrapyrrolic macrocy...
Figure 20: a) Chemical structures of tetrapyrrolic macrocycles 109, 73, and 110 used for oxygen reductions in ...
Figure 21: a) Absorption spectra (left) of the air-saturated DCE solutions containing: 5 × 10−5 M H2TPP (black...
Figure 22: Chemical structures of N,N’-dimethylated saddle-distorted porphyrin isomers, syn-Me2P 111 and anti-...
Figure 23: Reaction mechanisms for the two-electron reduction of O2 by a) syn-Me2Iph 113 and b) anti-Me2Iph 114...
Figure 24: O2/H2O2 interconversion using methylated saddle-distorted porphyrin and isophlorin (reduced porphyr...
Figure 25: Chemical structures of distorted dodecaphenylporphyrin macrocycle 117 and its diprotonated form 118...
Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252
Graphical Abstract
Figure 1: Overview of the CD-based rotaxane as a polymer material covered in this review.
Figure 2: CD structure.
Figure 3: Typical pathway for synthesizing CD-based rotaxanes.
Scheme 1: (A) Synthesis of α-CD-based [2]rotaxane via a metal–ligand complex. (B) Chemical structures of meth...
Scheme 2: Synthesis of α-CD-based polyrotaxane.
Scheme 3: Facile [3]rotaxane synthesis by the urea end-capping method.
Figure 4: (A) Single-crystal structure of α-CD-based [3]rotaxane 3 and PMα-CD-based [3]rotaxane 4. (B) Schema...
Figure 5: Structural control of CD-based [2]rotaxane via (A) light irradiation and (B) light irradiation and ...
Figure 6: Relationship among the plus–minus signs of ICD, the position of the guest molecule, and the axis of...
Figure 7: Structural control of CD-based rotaxane via (A) redox reaction and (B) in a solvent.
Scheme 4: (A) Synthesis of pseudopolyrotaxane bearing an ABA triblock copolymer as an axle. (B) Two synthetic...
Scheme 5: Slippage of size-complementary rotaxanes.
Figure 8: (A) Reversible formation of the CD-based [2]rotaxane. (B) Deslipping reaction of the CD-based size-...
Figure 9: (A) Chemical structures of [3]rotaxanes 2 and 3. (B) Schematic of the deslipping reaction of [3]rot...
Figure 10: (A) Modification of the axle ends of [3]rotaxane by (1) bromination and (2) the Suzuki coupling rea...
Figure 11: (A) ICD spectra of [3]rotaxanes bearing acylated (top) and conventional (bottom) CDs. (B) Schematic...
Figure 12: Synthesis of macromolecular[3]rotaxane via a size-complementary protocol.
Figure 13: Conjugated polymer insulated by (A) β-CD. (B) Triphenylamine-substituted β-CD.
Figure 14: Synthesis of the VSC and successive rotaxane-crosslinked polymer (RCP) preparation.
Figure 15: (A) Chemical structure of the [3]rotaxane crosslinker (RC). (B) Schematic of the synthesis and de-c...
Figure 16: (A) Random vinylation of the CD-based [3]rotaxane; (B) Schematic of the reaction between α-CD and m...
Figure 17: (A) Aggregation of CD-based [3]rotaxane. (B) Schematic of the plausible mechanism of the aggregatio...
Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251
Graphical Abstract
Figure 1: Structure of previously synthesized stilbazoles А and arylidene derivatives of pyrindane 1 reported...
Scheme 1: Synthesis of donor–acceptor 1-pyrindane derivatives 1.
Figure 2: 1H,1H-NOESY spectrum of compound 1c in DMSO-d6.
Figure 3: Absorption (left) and normalized emission spectra (right) of compound 1i in various solvents (c = 10...
Scheme 2: Plausible equilibrium of compounds 1i and 1iH+ in acidic solution.
Figure 4: Solvatochromic behavior of compounds 1c and 1i: plots of arithmetic mean of emission/absorption wav...
Figure 5: Absorption spectra of compounds 1a–i in toluene (left) and DMSO (right, c = 10−5 M).
Figure 6: Normalized emission spectra of compounds 1a–i in toluene (left) and DMSO (right, c = 10−5 M).
Figure 7: Photos of fluorescent solutions of compounds 1a–i in toluene (top) and DMSO (bottom) taken under a ...
Figure 8: Normalized solid-state emission spectra of compounds 1a–i (bottom) and photos of powders taken unde...
Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240
Graphical Abstract
Scheme 1: Structures of indigo (1a), indirubin (2a) and isoindigo (3a).
Scheme 2: Structures of akashins A–C.
Scheme 3: Synthesis of 5b. Reagents and conditions: i) TMSOTf, 4 Å MS, CH2Cl2, −20 °C, 1.5 h, then 20 °C, 8–1...
Scheme 4: Synthesis of 7c. Reagents and conditions: i) TMSOTf, 4 Å MS, CH2Cl2, −18 °C, 3 h; then: TMSOTf, 4 Å...
Scheme 5: Synthesis of 1d. Reagents and conditions: i) chloroacetic acid, Na2CO3, reflux, 6 h; ii) Ac2O, NaOA...
Scheme 6: Synthesis of 10e. Reagents and conditions: i) p-TsOH·H2O, acetonitrile, MeOH, 1 d; ii) NIS, PPh3, D...
Scheme 7: Synthesis of akashins A–C. Reagents and conditions: i) TMSOTf, 4 Å MS, CH2Cl2, −18 to 20 °C, 15 h; ...
Scheme 8: Synthesis of 5d. Reagents and conditions: i) KMnO4, AcOH, high-power-stirring (12.000 rot/min), 20 ...
Scheme 9: Possible mechanism of the formation of 5c.
Scheme 10: Synthesis of 7d. Reagents and conditions: i) 1) CH2Cl2, 2) Me3SiI, 20 °C, 30 min, 3) 0 °C, 30 min, ...
Scheme 11: Synthesis of α-15b. Reagents and conditions: i) 1) CH2Cl2, 2) Me3SiI, 20 °C, 30 min, 3) 0 °C, 30 mi...
Scheme 12: Synthesis of isatin-N-glycosides 16a–f. Reagents and conditions: i) PhNH2, EtOH, 20 °C, 12 h; ii) Ac...
Scheme 13: Synthesis of 17–21. Reagents and conditions: i) Na2CO3, MeOH, 20 °C, 4 h.
Scheme 14: Synthesis of indirubin-N-glycosides α-17a and α-17b.
Scheme 15: Synthesis of β-17f. Reagents and conditions: i) 1) Na2CO3, MeOH, 20 °C, 4 h, 2) Ac2O/pyridine 1:1, ...
Scheme 16: Synthesis of β-24a. Reagents and conditions: i) n-PrOH, H2O, formic acid (buffer, 100 mM), 2 h, 65 ...
Scheme 17: Synthesis of isatin-N-glycosides 23b–g and 24b–g.
Scheme 18: Synthesis of β-29a,b. Reagents and conditions: i) EtOH, 20 °C, 12 h; ii) DDQ, dioxane, 20 °C, 12 h;...
Scheme 19: Synthesis of β-31a. Reagents and conditions: i) Na2SO3, dioxane, H2O, 110 °C, 2 d; ii) piperidine, ...
Scheme 20: Synthesis of 33a–d. Reagents and conditions: i) Ac2O, AcOH, NaOAc, 80 °C, 1 h; ii) 1) NaOMe, anhydr...
Scheme 21: Indirubins 34 and 35.
Scheme 22: Synthesis of 36f. Reagents and conditions: i) NaOH, H2O, 20 °C, 5 h; ii) HCl, NaNO2, H2O, −14 °C; i...
Scheme 23: Synthesis of 38a–h. Reagents and conditions: i) 1) 0.1 equiv NaOMe, MeOH, 20 °C, 15–20 min, 2) HOAc...
Scheme 24: Synthesis of 40a–h. Reagents and conditions: i) method A: EtOH/THF, cat. KOt-Bu, 20 °C, 3–4.5 h; me...
Scheme 25: Synthesis of 41a–d. Reagents and conditions: i) Ac2O, AcOH, NaOAc, 80 °C, 1 h.
Scheme 26: Synthesis of 41e. Reagents and conditions: i) AcOH, NaOAc, 110 °C, 24 h.
Scheme 27: Synthesis of E-β-43a–e and E-β-44a,b. Reagents and conditions: i) 1) NEt3, EtOH, 20 °C, 12 h, 2) DM...
Scheme 28: Synthesis of E-43f. Reagents and conditions: i) Na2CO3, MeOH, 20 °C, 6–24 h.
Scheme 29: Synthesis of 46a–m. Reagents and conditions: i) NEt3 (1 equiv), EtOH, 20 °C, 6–10 h; ii) MsCl, NEt3...
Scheme 30: Synthesis of 48a–d. Reagents and conditions: i) AcOH/Ac2O, NaOAc, 60 °C, 3–4 h.
Scheme 31: Synthesis of 48e. Reagents and conditions: i) NaOAc, AcOH, 110 °C, 24 h.
Scheme 32: Synthesis of β-49a,b. Reagents and conditions: i) AcOH/Ac2O, NaOAc, 60 °C, 3–4 h.
Scheme 33: Synthesis of β-54a,b. Reagents and conditions: i) 1) NaH, DMF, 0 °C, 15 min, 2) β-51a,b, 20 °C, 3 h...
Scheme 34: Synthesis of 54c–l. The yields refer to the yields of the first and second condensation step for ea...
Scheme 35: Synthesis of 57a–c and 58a–d. Reagents and conditions: i) HCl (conc.), AcOH, reflux, 24 h; ii) 1) B...
Scheme 36: Synthesis of 59a–e and 60a–e. Reagents and conditions: i) P(NEt2)3 (1.1 equiv), CH2Cl2, −78 °C to 2...
Scheme 37: Synthesis of 61a–d and 62a–d. Reagents and conditions: i) P(NEt2)3 (1.1 equiv), CH2Cl2, −78 °C to 2...
Scheme 38: Synthesis of β-64a–e and α-64a. Reagents and conditions: i) AcOH, Ac2O, NaOAc, 90 °C, 6 h.
Scheme 39: Synthesis of β-72a. Reagents and conditions: i) 66, EtOH, 20 °C, 12 h; ii) DDQ, dioxane, 20 °C, 12 ...
Scheme 40: Synthesis of β-72b.
Scheme 41: Synthesis of β-74a–c. Reagents and conditions: i) AcOH, Ac2O, NaOAc, 130 °C, 2 d.
Scheme 42: Synthesis of β-77. Reagents and conditions: i) 1) NEt3, EtOH, 20 °C, 12 h, 2) DMAP, NEt3, MsCl, 0 °...
Scheme 43: Synthesis of β-81a–f and β-80g. Reagents and conditions: i) AcOH, 80 °C, 1–3 h; ii) benzene, PTSA, ...
Scheme 44: Synthesis of 84a. Reagents and conditions: i) benzene, AlCl3, 20 °C, 10 min; ii) MeOH, NaOMe, 12 h,...
Scheme 45: Synthesis of 84b–l. The yields refer to the yields of the condensation and the deprotection step fo...
Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220
Graphical Abstract
Figure 1: Hierarchical assembly occurring across length scales. Molecular interactions result in fibres which...
Figure 2: Three-dimensional CLSM image of a multicomponent supramolecular structure. The three-dimensional CL...
Figure 3: AFM images of air-dried aqueous Fmoc-FF, Fmoc-S, and 1:1 Fmoc-FF:Fmoc-S solutions. Figure 3 was reprinted f...
Figure 4: (a) 3D CLSM images of macroscopically a self-sorting gel network, where all fibres were stained gre...
Figure 5: (a) 3D AFM topographic image of dried elastin fibre. (b) Indicative height and diameter profile plo...
Figure 6: The nano-to-micro imaging range of SEM and TEM [30]. Cartoons represent the nanoparticles, pores, nanow...
Figure 7: Cartoon of artifacts caused by blotting and thinning. a) Alignment of threadlike micelles (left) [32] a...
Figure 8: (a) Chemical structures of monomer compounds and a schematic of the resulting chiral helical struct...
Figure 9: Commonly observed entanglements of urea-based supramolecular helices. (a) Double helix, (b) quadrup...
Figure 10: (a) SEM image of a single three-stranded braid showing a defect in which the braid separates into s...
Figure 11: Visualization of individual atoms at 1.25 Å resolution. Three apoferritin residues are shown at hig...
Figure 12: Cartoon of a general small-angle scattering setup.
Figure 13: (a) SAXS data and fits for solution in H2O (open symbols) and D2O (closed symbols). Cryo-TEM data f...
Figure 14: (a) A cartoon illustrating the orientation phases caused by shear alignment of WLMs. (b) Rheologica...
Figure 15: (a) Chemical structure of 2NapFF and (b) a cartoon cross-section of the hollow cylinder structure f...
Figure 16: Length scales of scattering and imaging techniques [16,54,55].
Figure 17: A schematic of a hydrogel network showing the significance of various parameters extracted from SAN...
Figure 18: The morphologies of a co-assembled complex dependent on the solvent composition. Figure 18 is from [89] and was ...
Figure 19: Allowed and forbidden crossings of entangled helices. Figure 19 is from [44] and was adapted by permission from ...
Figure 20: (a) Cryo-TEM density map of self-assembled (ʟ,ʟ)-2NapFF. (b) Computational model fit to cryo-TEM ma...
Figure 21: Map showing an incomplete list of global scientific centres providing access to (a) cryo-EM in red ...
Figure 22: SANS at a range of times. Solid lines are fits to a hollow cylinder model (T = 114 min and T = 202 ...
Figure 23: SAXS data of 5 mg/mL alanine-functionalised perylene bisimide (PBI-A) in 20 v/v % MeOH at pH (a) 2;...
Figure 24: Cryo-TEM sample prepared using plunge freezing in liquid nitrogen slush and sublimed for 30 minutes...
Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216
Graphical Abstract
Scheme 1: (a) Conventional methods for the generation of Ar• from Ar3Bi, (b) our previous studies, and (c) th...
Scheme 2: Scope for transition-metal-free synthesis of arylboronates 3 using triaylbismuthines 1 and diboron 2...
Scheme 3: Control experiment of the metal-free borylation under an argon atmosphere.
Figure 1: Comparison of the crude mixture of the reactions under (a) argon atmosphere or (b) open-air.
Scheme 4: Radical-trapping experiments using TEMPO as a radical scavenger.
Scheme 5: A proposed reaction pathway for the synthesis of arylboronates.
Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214
Graphical Abstract
Figure 1: Classification of LSF reactions in this review.
Scheme 1: C(sp2)–H trifluoromethylation of heteroarenes.
Scheme 2: C(sp2)–H and C(sp3)–H alkylation of complex molecules.
Scheme 3: Electrochemical oxidation-induced intermolecular aromatic C–H sulfonamidation.
Scheme 4: Bioconjugation of tyrosine with (a) phenothiazine and (b) urazole derivatives.
Scheme 5: Electrochemical iodoamination of indoles using unactivated amines.
Scheme 6: Allylic C(sp3)–H aminations with sulfonamides.
Scheme 7: Electrochemical benzylic oxidation of C–H bonds.
Scheme 8: Site-selective electrooxidation of methylarenes to aromatic acetals.
Scheme 9: Electrochemical activation of C–H by electron-deficient W2C nanocrystals.
Scheme 10: α-Acyloxy sulfide preparation via C–H/OH cross-dehydrogenative coupling.
Scheme 11: Aromatic C–H-bond thiolation.
Scheme 12: C(sp2)–H functionalization for the installation of sulfonamide groups.
Scheme 13: Preparation of (hetero)aryl chlorides and vinyl chloride with 1,2-dichloroethane. aCu(OAc)2 (0.05 e...
Scheme 14: Electrochemical dual-oxidation enables access to α-chlorosulfoxides.
Scheme 15: Regio- and chemoselective formyloxylation–bromination/chlorination/trifluoromethylation of alkenes.
Scheme 16: Aziridine formation by coupling amines and alkenes.
Scheme 17: Formation of iminosulfide ethers via difunctionalization of an isocyanide.
Scheme 18: Synthesis of 1,3-difunctionalized molecules via C–C-bond cleavage of arylcyclopropane.
Scheme 19: Electrooxidative amino- and oxyselenation of alkenes. VBImBr = 1-butyl-3-vinylimidazolium bromide.
Scheme 20: Electrooxidative dehydrogenative [4 + 2] annulation of indole derivatives.
Scheme 21: Electrochemical cyclization combined with alkoxylation of triticonazole.
Scheme 22: Electrochemically tuned oxidative [4 + 2] annulation of olefins with hydroxamic acids.
Scheme 23: Electrosynthesis of indole derivatives via cyclization of 2-ethynylanilines.
Scheme 24: Allylic C–H oxidation of mono-, di-, and sesquiterpenes.
Scheme 25: Oxidation of unactivated C–H bonds.
Scheme 26: Fluorination of C(sp3)–H bonds. rAP = rapid alternating polarity.
Scheme 27: C(sp3)–H α-cyanation of secondary piperidines.
Scheme 28: Selective electrochemical hydrolysis of hydrosilanes to silanols.
Scheme 29: Organocatalytic electrochemical amination of benzylic C–H bonds.
Scheme 30: Iodide ion-initiated anodic oxidation reactions.
Scheme 31: Mn(III/IV) electro-catalyzed C(sp3)–H azidation.
Scheme 32: Tailored cobalt–salen complexes enable electrocatalytic intramolecular allylic C–H functionalizatio...
Scheme 33: Cobalt–salen complexes-induced electrochemical (cyclo)additions.
Scheme 34: Electrochemical 1,2-diarylation of alkenes enabled by direct dual C–H functionalization of electron...
Scheme 35: Cobalt-electrocatalyzed atroposelective C–H annulation.
Scheme 36: Nickel-electrocatalyzed C(sp2)–H alkoxylation with secondary alcohols.
Scheme 37: Nickel-catalyzed electrochemical enantioselective amination.
Scheme 38: Ruthenium-electrocatalyzed C(sp2)–H mono- and diacetoxylation.
Scheme 39: Rhodium(III)-catalyzed aryl-C–H phosphorylation enabled by anodic oxidation-induced reductive elimi...
Scheme 40: Asymmetric Lewis-acid catalysis for the synthesis of non-racemic 1,4-dicarbonyl compounds.
Scheme 41: Electrochemical enantioselective C(sp3)–H alkenylation.
Scheme 42: Palladium-catalyzed electrochemical dehydrogenative cross-coupling.
Scheme 43: Ir-electrocatalyzed vinylic C(sp2)–H activation for the annulation between acrylic acids and alkyne...
Scheme 44: Electrochemical gold-catalyzed C(sp3)–C(sp) coupling of alkynes and arylhydrazines.
Scheme 45: Photoelectrochemical alkylation of C–H heteroarenes using organotrifluoroborates.
Scheme 46: Mn-catalyzed photoelectro C(sp3)–H azidation.
Scheme 47: Photoelectrochemical undirected C–H trifluoromethylations of (Het)arenes.
Scheme 48: Photoelectrochemical dehydrogenative cross-coupling of heteroarenes with aliphatic C–H bonds.
Scheme 49: C–H amination via photoelectrochemical Ritter-type reaction.
Scheme 50: Photoelectrochemical multiple oxygenation of C–H bonds.
Scheme 51: Accelerated C(sp3)–H heteroarylations by the f-EPC system.
Scheme 52: Photoelectrochemical cross-coupling of amines.
Scheme 53: Birch electroreduction of arenes. GSW = galvanized steel wire.
Scheme 54: Electroreductive deuterations.
Scheme 55: Chemoselective electrosynthesis using rapid alternating polarity.
Scheme 56: Electroreductive olefin–ketone coupling.
Scheme 57: Electroreductive approach to radical silylation.
Scheme 58: Electrochemical borylation of alkyl halides. CC = carbon close.
Scheme 59: Radical fluoroalkylation of alkenes.
Scheme 60: Electrochemical defluorinative hydrogenation/carboxylation.
Scheme 61: Electrochemical decarboxylative olefination.
Scheme 62: Electrochemical decarboxylative Nozaki–Hiyama–Kishi coupling.
Scheme 63: Nickel-catalyzed electrochemical reductive relay cross-coupling.
Scheme 64: Electrochemical chemo- and regioselective difunctionalization of 1,3-enynes.
Scheme 65: Electrocatalytic doubly decarboxylative crosscoupling.
Scheme 66: Electrocatalytic decarboxylative crosscoupling with aryl halides.
Scheme 67: Nickel-catalyzed electrochemical reductive coupling of halides.
Scheme 68: Nickel-electrocatalyzed enantioselective carboxylation with CO2.
Scheme 69: Reductive electrophotocatalysis for borylation.
Scheme 70: Electromediated photoredox catalysis for selective C(sp3)–O cleavages of phosphinated alcohols to c...
Scheme 71: Stereoselective electro-2-deoxyglycosylation from glycals. MFE = methyl nonafluorobutyl ether.
Scheme 72: Electrochemical peptide modifications.
Scheme 73: Electrochemical α-deuteration of amides.
Scheme 74: Electrochemical synthesis of gem-diselenides.
Scheme 75: Site-selective electrochemical aromatic C–H amination.
Scheme 76: Electrochemical coupling of heteroarenes with heteroaryl phosphonium salts.
Scheme 77: Redox-neutral strategy for the dehydroxyarylation reaction.
Scheme 78: Nickel-catalyzed electrochemical C(sp3)–C(sp2) cross-coupling of benzyl trifluoroborate and halides....
Scheme 79: Paired electrocatalysis for C(sp3)–C(sp2) coupling.
Scheme 80: Redox-neutral strategy for amination of aryl bromides.
Scheme 81: Redox-neutral cross-coupling of aryl halides with weak N-nucleophiles. aProtocol with (+) RVC | RVC...
Scheme 82: Nickel-catalyzed N-arylation of NH-sulfoximines with aryl halides.
Scheme 83: Esterification of carboxylic acids with aryl halides.
Scheme 84: Electrochemically promoted nickel-catalyzed carbon–sulfur-bond formation. GFE = graphite felt elect...
Scheme 85: Electrochemical deoxygenative thiolation by Ni-catalysis. GFE = graphite felt electrode; NFE = nick...
Scheme 86: Electrochemical coupling of peptides with aryl halides.
Scheme 87: Paired electrolysis for the phosphorylation of aryl halides. GFE = graphite felt electrode, FNE = f...
Scheme 88: Redox-neutral alkoxyhalogenation of alkenes.
Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212
Graphical Abstract
Figure 1: Schematic diagram illustrating the data mining and preprocessing steps for chemical reaction datase...
Figure 2: A comparison of three types of reaction embedding methods: (A) descriptor-based, which use predefin...
Figure 3: A schematic diagram of how ML algorithms can be combined with HTE platforms to optimize reaction co...
Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210
Graphical Abstract
Figure 1: A) Photoredox amidocyclization reaction. B) The strongly oxidizing Fukuzumi catalyst (I) used in th...
Figure 2: A) Access of clavam derivatives by intramolecular photoredox reaction of alkenes. B) Clavulanic aci...
Scheme 1: Preparation of alkenyl β-lactam derivatives for the intramolecular photoredox reaction.
Scheme 2: Photoredox-catalyzed intramolecular N-alkylation reactions of various β-lactams. The trans/cis dr w...
Scheme 3: Synthesis of the model substrate 14 and its photoredox-catalyzed intramolecular N-alkylation reacti...
Figure 3: Tentative mechanism for the photo-cyclization reaction.
Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199
Graphical Abstract
Figure 1: Overall chemical proteomics strategy to identify protein targets of natural products (NPs) and simi...
Figure 2: A) Design of mostly used photo-crosslinking groups. B) Mass spectrometry properties of proteins PTM...
Figure 3: Direct and indirect approach to identify protein targets and representative chemical proteomics wor...
Figure 4: Products of the CuAAC side reactions.
Figure 5: Search possibilities on peptide-level characterization. A) Comparison of DDA and DIA techniques. B)...
Figure 6: In-gel analysis using a tag with fluorophore (A) or via shift-assay (B).
Figure 7: Reporter linkers. A) DMP-tag. B) AzidoTMT tag. C) SOX-tag. D) Imidazolium tag. *A star indicates th...
Figure 8: Biotin and desthiobition-based sample linkers and their associated diagnostic peaks. A) Structure o...
Figure 9: A) isoDTB linker and probe-specific diagnostic ions (B). *A star indicates the possible introductio...
Figure 10: TEV-cleavable linker structure with its characteristic diagnostic ions (A) and probe-specific diagn...
Figure 11: A) Structure of the full length DADPS linker and remaining part after cleavage. B) Diagnostic ions....
Figure 12: Diagnostic peaks included in the search identify higher numbers of modified PSMs and peptides using...
Figure 13: An alternative DADPS linker.
Figure 14: Chemical structure of the trifunctional trypsin cleavable AzKTB linker.
Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186
Graphical Abstract
Figure 1: Structures of some reported mono-, di- and tri-dipyrromethane derivatives [44-49].
Scheme 1: Synthesis of the mono-DPM-based truxene derivative 14.
Scheme 2: Synthesis of di- and tri-DPM-based truxene derivatives 16 and 18.
Figure 2: UV–vis absorption (left) and fluorescence spectra (right) recorded in chloroform.
Figure 3: Time-resolved fluorescence lifetime.
Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182
Graphical Abstract
Figure 1: Resonance structures and reactivity of carbon monoxide.
Figure 2: Resonance structures and reactivity of isocyanides.
Scheme 1: Possible three pathways of the E• formation for imidoylation.
Scheme 2: Radical addition of thiols to isocyanides.
Scheme 3: Selective thioselenation and catalytic dithiolation of isocyanides.
Scheme 4: Synthesis of carbacephem framework.
Scheme 5: Sequential addition of (PhSe)2 to ethyl propiolate and isocyanide.
Scheme 6: Isocyanide insertion reaction into carbon-tellurium bonds.
Scheme 7: Radical addition to isocyanides with disubstituted phosphines.
Scheme 8: Radical addition to phenyl isocyanides with diphosphines.
Scheme 9: Radical reaction of tin hydride and hydrosilane toward isocyanide.
Scheme 10: Isocyanide insertion into boron compounds.
Scheme 11: Isocyanide insertion into cyclic compounds containing boron units.
Scheme 12: Photoinduced hydrodefunctionalization of isocyanides.
Scheme 13: Tin hydride-mediated indole synthesis and cross-coupling.
Scheme 14: 2-Thioethanol-mediated radical cyclization of alkenyl isocyanide.
Scheme 15: Thiol-mediated radical cyclization of o-alkenylaryl isocyanide.
Scheme 16: (PhTe)2-assisted dithiolative cyclization of o-alkenylaryl isocyanide.
Scheme 17: Trapping imidoyl radicals with heteroatom moieties.
Scheme 18: Trapping imidoyl radicals with isocyano group.
Scheme 19: Quinoline synthesis via aza-Bergman cyclization.
Scheme 20: Phenanthridine synthesis via radical cyclization of 2-isocyanobiaryls.
Scheme 21: Phenanthridine synthesis by radical reactions with AIBN, DBP and TTMSS.
Scheme 22: Phenanthridine synthesis by oxidative cyclization of 2-isocyanobiaryls.
Scheme 23: Phenanthridine synthesis using a photoredox system.
Scheme 24: Phenanthridine synthesis induced by phosphorus-centered radicals.
Scheme 25: Phenanthridine synthesis induced by sulfur-centered radicals.
Scheme 26: Phenanthridine synthesis induced by boron-centered radicals.
Scheme 27: Phenanthridine synthesis by oxidative cyclization of 2-aminobiaryls.
Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169
Graphical Abstract
Scheme 1: Synthesis of new diketopyrrolopyrroles via nucleophilic aromatic substitution.
Figure 1: (A) Absorption and (B) fluorescence spectra of compounds 3a–f, 4a, 4d and 4f, in DMF. Different con...
Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137
Graphical Abstract
Figure 1: A) Benzylic fluorides in bioactive compounds, with B) the relative BDEs of different benzylic C–H b...
Figure 2: Base-mediated benzylic fluorination with Selectfluor.
Figure 3: Sonochemical base-mediated benzylic fluorination with Selectfluor.
Figure 4: Mono- and difluorination of nitrogen-containing heteroaromatic benzylic substrates.
Figure 5: Palladium-catalysed benzylic C–H fluorination with N-fluoro-2,4,6-trimethylpyridinium tetrafluorobo...
Figure 6: Palladium-catalysed, PIP-directed benzylic C(sp3)–H fluorination of α-amino acids and proposed mech...
Figure 7: Palladium-catalysed monodentate-directed benzylic C(sp3)–H fluorination of α-amino acids.
Figure 8: Palladium-catalysed bidentate-directed benzylic C(sp3)–H fluorination.
Figure 9: Palladium-catalysed benzylic fluorination using a transient directing group approach. Ratio refers ...
Figure 10: Outline for benzylic C(sp3)–H fluorination via radical intermediates.
Figure 11: Iron(II)-catalysed radical benzylic C(sp3)–H fluorination using Selectfluor.
Figure 12: Silver and amino acid-mediated benzylic fluorination.
Figure 13: Copper-catalysed radical benzylic C(sp3)–H fluorination using NFSI.
Figure 14: Copper-catalysed C(sp3)–H fluorination of benzylic substrates with electrochemical catalyst regener...
Figure 15: Iron-catalysed intramolecular fluorine-atom-transfer from N–F amides.
Figure 16: Vanadium-catalysed benzylic fluorination with Selectfluor.
Figure 17: NDHPI-catalysed radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 18: Potassium persulfate-mediated radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 19: Benzylic fluorination using triethylborane as a radical chain initiator.
Figure 20: Heterobenzylic C(sp3)–H radical fluorination with Selectfluor.
Figure 21: Benzylic fluorination of phenylacetic acids via a charge-transfer complex. NMR yields in parenthese...
Figure 22: Oxidative radical photochemical benzylic C(sp3)–H strategies.
Figure 23: 9-Fluorenone-catalysed photochemical radical benzylic fluorination with Selectfluor.
Figure 24: Xanthone-photocatalysed radical benzylic fluorination with Selectfluor II.
Figure 25: 1,2,4,5-Tetracyanobenzene-photocatalysed radical benzylic fluorination with Selectfluor.
Figure 26: Xanthone-catalysed benzylic fluorination in continuous flow.
Figure 27: Photochemical phenylalanine fluorination in peptides.
Figure 28: Decatungstate-photocatalyzed versus AIBN-initiated selective benzylic fluorination.
Figure 29: Benzylic fluorination using organic dye Acr+-Mes and Selectfluor.
Figure 30: Palladium-catalysed benzylic C(sp3)–H fluorination with nucleophilic fluoride.
Figure 31: Manganese-catalysed benzylic C(sp3)–H fluorination with AgF and Et3N·3HF and proposed mechanism. 19...
Figure 32: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with nucleophilic fluoride and N-ac...
Figure 33: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with TBPB HAT reagent.
Figure 34: Silver-catalysed, amide-promoted benzylic fluorination via a radical-polar crossover pathway.
Figure 35: General mechanism for oxidative electrochemical benzylic C(sp3)–H fluorination.
Figure 36: Electrochemical benzylic C(sp3)–H fluorination with HF·amine reagents.
Figure 37: Electrochemical benzylic C(sp3)–H fluorination with 1-ethyl-3-methylimidazolium trifluoromethanesul...
Figure 38: Electrochemical benzylic C(sp3)–H fluorination of phenylacetic acid esters with HF·amine reagents.
Figure 39: Electrochemical benzylic C(sp3)–H fluorination of triphenylmethane with PEG and CsF.
Figure 40: Electrochemical benzylic C(sp3)–H fluorination with caesium fluoride and fluorinated alcohol HFIP.
Figure 41: Electrochemical secondary and tertiary benzylic C(sp3)–H fluorination. GF = graphite felt. DCE = 1,...
Figure 42: Electrochemical primary benzylic C(sp3)–H fluorination of electron-poor toluene derivatives. Ring f...
Figure 43: Electrochemical primary benzylic C(sp3)–H fluorination utilizing pulsed current electrolysis.
Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119
Graphical Abstract
Figure 1: Generation of alkyl and acyl radicals via C–O bond breaking.
Figure 2: General photocatalytic mechanism.
Scheme 1: Photoredox-catalyzed hydroacylation of olefins with aliphatic carboxylic acids.
Scheme 2: Acylation–aromatization of p-quinone methides using carboxylic acids.
Scheme 3: Visible-light-induced deoxygenation–defluorination for the synthesis of γ,γ-difluoroallylic ketones....
Scheme 4: Photochemical hydroacylation of azobenzenes with carboxylic acids.
Scheme 5: Photoredox-catalyzed synthesis of flavonoids.
Scheme 6: Synthesis of O-thiocarbamates and photocatalytic reduction of O-thiocarbamates.
Scheme 7: Deoxygenative borylation of alcohols.
Scheme 8: Trifluoromethylation of O-alkyl thiocarbonyl substrates.
Scheme 9: Redox-neutral radical coupling reactions of alkyl oxalates and Michael acceptors.
Scheme 10: Visible-light-catalyzed and Ni-mediated syn-alkylarylation of alkynes.
Scheme 11: 1,2-Alkylarylation of alkenes with aryl halides and alkyl oxalates.
Scheme 12: Deoxygenative borylation of oxalates.
Scheme 13: Coupling of N-phthalimidoyl oxalates with various acceptors.
Scheme 14: Cross-coupling of O-alkyl xanthates with aryl halides via dual photoredox and nickel catalysis.
Scheme 15: Deoxygenative borylation of secondary alcohol.
Scheme 16: Deoxygenative alkyl radical generation from alcohols under visible-light photoredox conditions.
Scheme 17: Deoxygenative alkylation via alkoxy radicals against hydrogenation or β-fragmentation.
Scheme 18: Direct C–O bond activation of benzyl alcohols.
Scheme 19: Deoxygenative arylation of alcohols using NHC to activate alcohols.
Scheme 20: Deoxygenative conjugate addition of alcohol using NHC as alcohol activator.
Scheme 21: Synthesis of polysubstituted aldehydes.
Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87
Graphical Abstract
Scheme 1: Pd(0)-catalyzed domino C,N-coupling/carbonylation/Suzuki coupling reaction for the synthesis of 2-a...
Scheme 2: Pd(0)-catalyzed single isonitrile insertion: synthesis of 1-(3-amino)-1H-indol-2-yl)-1-ketones.
Scheme 3: Pd(0)-catalyzed gas-free carbonylation of 2-alkynylanilines to 1-(1H-indol-1-yl)-2-arylethan-1-ones....
Scheme 4: Pd(II)-catalyzed heterocyclization/alkoxycarbonylation of 2-alkynylaniline imines.
Scheme 5: Pd(II)-catalyzed heterocyclization/alkoxycarbonylation of 2-alkynylanilines to N-substituted indole...
Scheme 6: Synthesis of indol-2-acetic esters by Pd(II)-catalyzed carbonylation of 1-(2-aminoaryl)-2-yn-1-ols.
Scheme 7: Pd(II)-catalyzed carbonylative double cyclization of suitably functionalized 2-alkynylanilines to 3...
Scheme 8: Indole synthesis by deoxygenation reactions of nitro compounds reported by Cenini et al. [21].
Scheme 9: Indole synthesis by reduction of nitro compounds: approach reported by Watanabe et al. [22].
Scheme 10: Indole synthesis from o-nitrostyrene compounds as reported by Söderberg and co-workers [23].
Scheme 11: Synthesis of fused indoles (top) and natural indoles present in two species of European Basidiomyce...
Scheme 12: Synthesis of 1,2-dihydro-4(3H)-carbazolones through N-heteroannulation of functionalized 2-nitrosty...
Scheme 13: Synthesis of indoles from o-nitrostyrenes by using Pd(OAc)2 and Pd(tfa)2 in conjunction with bident...
Scheme 14: Synthesis of substituted 3-alkoxyindoles via palladium-catalyzed reductive N-heteroannulation.
Scheme 15: Synthesis of 3-arylindoles by palladium-catalyzed C–H bond amination via reduction of nitroalkenes.
Scheme 16: Synthesis of 2,2′-bi-1H-indoles, 2,3′-bi-1H-indoles, 3,3′-bi-1H-indoles, indolo[3,2-b]indoles, indo...
Scheme 17: Pd-catalyzed reductive cyclization of 1,2-bis(2-nitrophenyl)ethene and 1,1-bis(2-nitrophenyl)ethene...
Scheme 18: Flow synthesis of 2-substituted indoles by reductive carbonylation.
Scheme 19: Pd-catalyzed synthesis of variously substituted 3H-indoles from nitrostyrenes by using Mo(CO)6 as C...
Scheme 20: Synthesis of indoles from substituted 2-nitrostyrenes (top) and ω-nitrostyrenes (bottom) via reduct...
Scheme 21: Synthesis of indoles from substituted 2-nitrostyrenes with formic acid as CO source.
Scheme 22: Ni-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides (top) and the Ni-catalyze...
Scheme 23: Mechanism of the Ni-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides (top) an...
Scheme 24: Route to indole derivatives through Rh-catalyzed benzannulation of heteroaryl propargylic esters fa...
Scheme 25: Pd-catalyzed cyclization of 2-(2-haloaryl)indoles reported by Yoo and co-workers [54], Guo and co-worke...
Scheme 26: Approach for the synthesis of 6H-isoindolo[2,1-a]indol-6-ones reported by Huang and co-workers [57].
Scheme 27: Zhou group’s method for the synthesis of 6H-isoindolo[2,1-a]indol-6-ones.
Scheme 28: Synthesis of 6H-isoindolo[2,1-a]indol-6-ones from o-1,2-dibromobenzene and indole derivatives by us...
Scheme 29: Pd(OAc)2-catalyzed Heck cyclization of 2-(2-bromophenyl)-1-alkyl-1H-indoles reported by Guo et al. [55]....
Scheme 30: Synthesis of indolo[1,2-a]quinoxalinone derivatives through Pd/Cu co-catalyzed carbonylative cycliz...
Scheme 31: Pd-catalyzed carbonylative cyclization of o-indolylarylamines and N-monosubstituted o-indolylarylam...
Scheme 32: Pd-catalyzed diasteroselective carbonylative cyclodearomatization of N-(2-bromobenzoyl)indoles with...
Scheme 33: Pd(0)-catalyzed synthesis of CO-linked heterocyclic scaffolds from alkene-indole derivatives and 2-...
Scheme 34: Proposed mechanism for the Pd(0)-catalyzed synthesis of CO-linked heterocyclic scaffolds.
Scheme 35: Pd-catalyzed C–H and N–H alkoxycarbonylation of indole derivatives to indole-3-carboxylates and ind...
Scheme 36: Rh-catalyzed C–H alcoxycarbonylation of indole derivatives to indole-3-carboxylates reported by Li ...
Scheme 37: Pd-catalyzed C–H alkoxycarbonylation of indole derivatives with alcohols and phenols to indole-3-ca...
Scheme 38: Synthesis of N-methylindole-3-carboxylates from N-methylindoles and phenols through metal-catalyst-...
Scheme 39: Synthesis of indol-3-α-ketoamides (top) and indol-3-amides (bottom) via direct double- and monoamin...
Scheme 40: The direct Sonogashira carbonylation coupling reaction of indoles and alkynes via Pd/CuI catalysis ...
Scheme 41: Synthesis of indole-3-yl aryl ketones reported by Zhao and co-workers [73] (path a) and Zhang and co-wo...
Scheme 42: Pd-catalyzed carbonylative synthesis of BIMs from aryl iodides and N-substituted and NH-free indole...
Scheme 43: Cu-catalyzed direct double-carbonylation and monocarbonylation of indoles and alcohols with hexaket...
Scheme 44: Rh-catalyzed direct C–H alkoxycarbonylation of indoles to indole-2-carboxylates [79] (top) and Co-catal...
Scheme 45: Pd-catalyzed carbonylation of NH free-haloindoles.
Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45
Graphical Abstract
Figure 1: Principle of switchable molecular tweezers.
Figure 2: Principle of pH-switchable molecular tweezers 1 [19].
Figure 3: a) pH-Switchable tweezers 2 substituted with alkyl chains as switchable lipids. b) Schematic depict...
Figure 4: Modification of spectral properties of 3 by controlled induction of Pt–Pt interactions.
Figure 5: Conformational switching of di(hydroxyphenyl)pyrimidine-based tweezer 4 upon alkylation or fluoride...
Figure 6: Hydrazone-based pH-responsive tweezers 5 for mesogenic modulation.
Figure 7: pH-Switchable molecular tweezers 6 bearing acridinium moieties.
Figure 8: a) Terpyridine and pyridine-hydrazone-pyridine analogs molecular tweezers and b) extended pyridine ...
Figure 9: Terpyridine-based molecular tweezers with M–salphen arms and their field of application. Figure 9 was adapt...
Figure 10: a) Terpyridine-based molecular tweezers for diphosphate recognition [48]; b) bishelicene chiroptical te...
Figure 11: Terpyridine-based molecular tweezers with allosteric cooperative binding.
Figure 12: Terpyridine-based molecular tweezers presenting closed by default conformation.
Figure 13: Pyridine-pyrimidine-pyridine-based molecular tweezers.
Figure 14: Coordination-responsive molecular tweezers based on nitrogen-containing ligands.
Figure 15: Molecular tweezers exploiting the remote bipyridine or pyridine binding to trigger the conformation...
Figure 16: Bipyridine-based molecular tweezers exploiting the direct s-trans to s-cis-switching for a) anion b...
Figure 17: a) Podand-based molecular tweezers [66,67]. b) Application of tweezers 32 for the catalytic allosteric reg...
Figure 18: Anion-triggered molecular tweezers based on calix[4]pyrrole.
Figure 19: Anion-triggered molecular tweezers.
Figure 20: a) Principle of the weak link approach (WLA) developed by Mirkin and its application to b) symmetri...
Figure 21: Molecular tweezers as allosteric catalyst in asymmetric epoxide opening [80].
Figure 22: Allosteric regulation of catalytic activity in ring-opening polymerization with double tweezers 41.
Figure 23: a) Conformational switching of 42 by intramolecular –S–S– bridge formation. b) Shift of conformatio...
Figure 24: a) Redox-active glycoluril-TTF tweezers 44. b) Mechanism of stepwise oxidation of said tweezers wit...
Figure 25: Mechanism of formation of the mixed-valence dimers of tweezers 45.
Figure 26: Mechanism of carbohydrate liberation upon redox-mediated conformation switching of 46.
Figure 27: a) The encapsulation properties of 47 as well as the DCTNF release process from its host–guest comp...
Figure 28: Redox-active bipyridinium-based tweezers. a) With a ferrocenyl hinge 49, b) with a propyl hinge 50 ...
Figure 29: Redox-active calix[4]arene porphyrin molecular tweezers.
Figure 30: a) Mechanism of the three orthogonal stimuli. b) Cubic scheme showing the eight different states of ...
Figure 31: Redox-controlled molecular gripper based on a diquinone resorcin[4]arene.
Figure 32: a) Shinkai's butterfly tweezers and their different host–guest properties depending on the isomer. ...
Figure 33: Cyclam-tethered tweezers and their different host–guest complexes depending on their configuration.
Figure 34: Azobenzene-based catalytic tweezers.
Figure 35: Photoswitchable PIEZO channel mimic.
Figure 36: Stilbene-based porphyrin tweezers for fullerene recognition.
Figure 37: Stiff-stilbene-based tweezers with urea or thiourea functional units for a) anion binding, b) anion...
Figure 38: Feringa’s photoswitchable organocatalyst (a) and different catalyzed reactions with that system (b)....
Figure 39: a) Irie and Takeshita’s thioindigo-based molecular tweezers. b) Family of hemithioindigo-based mole...
Figure 40: Dithienylethylene crown ether-bearing molecular tweezers reported by Irie and co-workers.
Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34
Graphical Abstract
Scheme 1: Synthesis of 6,8-di-tert-butyl-N-aryl-3H-phenoxazin-3-imines 3 [6] and 6,8-di-tert-butyl-2-(arylamino)...
Figure 1: DFT-calculated molecular geometry (B3LYP/6-311++G(d,p) level) and distribution of electronic densit...
Scheme 2: 6,8-Di-tert-butyl-2-(arylamino)-3H-phenoxazin-3-ones 4 prepared by the one-pot reaction between 6,8...
Figure 2: Molecular structure of 6,8-di-tert-butyl-2-(o-nitrophenylamino)-3H-phenoxazin-3-one (4f). a) Select...
Figure 3: UV–vis spectra of 6,8-di-tert-butyl-2-(arylamino)-3H-phenoxazin-3-ones 4a–h (toluene, c = 2⋅10−5 M, ...
Scheme 3: Synthesis of 14H-quinoxaline[2,3-b]phenoxazines 5 and 6.
Scheme 4: Relative stability of the tautomers 7 and 7a,b of quinoxaline[2,3-b]phenoxazine calculated at the D...
Scheme 5: Preparation of quinoxaline[2,3-b]phenoxazine (7) from 2-amino-3H-phenoxazin-3-one (8) [10] and 2-ethoxy...
Figure 4: Molecular structure of ethyl 2,4-di-tert-butyl-14H-quinoxalino[2,3-b]phenoxazine-10-carboxylate (5c...
Scheme 6: Triphenodioxazine and oxazinophenothiazine derivatives 10 via condensation of 3H-phenoxazin-3-one 1...
Figure 5: a) UV–vis (solid lines) and fluorescence emission (λex = 365 nm, dashed) spectra of compounds 5a–c ...
Figure 6: UV–vis (solid lines) and fluorescence emission (dashed, λex = 365 nm) spectra of compounds 6a,b in ...
Figure 7: UV–vis, fluorescence emission (λex = 500 nm), and fluorescence excitation (λobs = 590 nm) spectra o...
Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23
Graphical Abstract
Figure 1: Precursors used in the synthesis of indigo [4].
Figure 2: a) Intramolecular (a = 2.26 Å) and intermolecular (b = 2.11 Å) hydrogen bonds in indigo, b) crystal...
Figure 3: Bond length in the indigo molecule obtained from the single crystal X-ray analysis [12], the typical bo...
Figure 4: The structure of the indigo chromophore (H-chromophore, highlighted in blue), asterisk indicates th...
Figure 5: Influence of substituents in the benzene rings on the color of indigo derivatives.
Figure 6: a) E–Z photoisomerization of indigo and b) photoinduced proton transfer in the excited state, aster...
Figure 7: Structures of indigo derivatives discussed in this review.
Figure 8: Photoswitching of N,N'-diacetylindigo (9a) in CCl4 (c = 17.1 µM; cell length = 5.0 cm) irradiated w...
Figure 9: Photoisomerization of compound 18c upon irradiation with red light and schematic representation of ...
Figure 10: Schematic representation of indigo-type (left) and amide-type (right) resonances in N,N'-acetylindi...
Figure 11: Suggested intermediates for the double bond cleavage for the thermal relaxation of N,N'-diacylindig...
Figure 12: Zwitterionic resonance structures of Z-indigo.
Figure 13: Photos of crystalline N,N'-di(Boc)indigo 17a its solutions in 1) DMSO, 2) DMF, 3) N-methyl-2-pyrrol...
Figure 14: Structural isomers of indigo.
Figure 15: Photochromism of indirubin derivatives and supramolecular complexation of the E-isomers with Schrei...
Figure 16: Photoisomerization of the protonated isoindigo.