Search results
Search for "biological activity" in Full Text gives 466 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones
- Ashutosh Nath,
- John Mark Awad and
- Wei Zhang
Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92
- group on the imidazopyridine moiety have direct electronic impact on the IMDA reaction. This integrated reaction process provided a new avenue for the preparation of heterocyclic scaffolds with potential biological activity. Experimental General procedure for the synthesis of intermediates 4 and 6 The
Graphical Abstract
Figure 1: Bioactive compounds bearing imidazopyridine (red) and isoquinolinone-kind (blue) rings.
Scheme 1: GBB-initiated synthesis of imidazopyridine-fused isoquinolinones.
Scheme 2: GBB reaction and N-acylation for the preparation of imidazo[1,2-a]pyridines 6.
Scheme 3: Substrate scope for IMDA and dehydrative aromatization in making 8. Reaction conditions: 6 and AlCl3...
Figure 2: Transition state analysis of IMDA reactions for 6a, 6j, 6h and 6r.
Figure 3: Relative energy diagram for the synthesis of 8a from 6a.
Scheme 4: Using thiophene-2-carbaldehyde for the synthesis of 8t.
Scheme 5: Proposed mechanisms for IMDA reaction and dehydration re-aromatization.
Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups
- Christian Akakpo,
- Peter Y. Zavalij and
- Lyle Isaacs
Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55
- biomedical applications including as a solubilizing excipient for anticancer agents and as an in vivo sequestrant to reverse the biological activity of neuromuscular blocking agents, anesthetics, and drugs of abuse (e.g., methamphetamine and fentanyl) [54][55][56][57][58][59][60]. As a result of their
Graphical Abstract
Figure 1: Chemical structures of CB[n] and selected acyclic CB[n]-type molecular containers M1 and M0.
Scheme 1: Synthesis of C1. Conditions: a) TFA/Ac2O, 70 °C, 3.5 h, 71%; b) LiOH, 50 °C, 69%; c) dry pyridine, ...
Figure 2: a) 1H NMR spectrum (600, D2O, rt) and b) 13C NMR spectrum recorded (150 MHz, D2O, rt) for C1.
Figure 3: Chemical structures of guests used in this study along with the complexation induced changes in che...
Figure 4: 1H NMR spectra recorded (400 MHz, D2O, rt) for: a) Me6PXDA (0.5 mM), b) a mixture of C1 (0.5 mM) an...
Figure 5: Cross-eyed stereoview of the C1·Me6CHDA complex in the crystal. Color code: C, gray; H, white; N, b...
Figure 6: Cross-eyed stereoview of the crystal packing observed in the molecular cell of C1·Me6CHDA. H-atoms ...
Figure 7: a) Representative plot of DP (μcal s−1) versus time from the titration of C1 (0.1 mM) in the ITC ce...
Origami with small molecules: exploiting the C–F bond as a conformational tool
- Patrick Ryan,
- Ramsha Iftikhar and
- Luke Hunter
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
- , dramatic differences in biological activity are sometimes seen between the fluorinated stereoisomers (e.g., 111 and 112) [189]. This difference can be attributed to a conformational effect, whereby fluorine controls the pucker of the 5-membered ring through σC–H → σ*C–F hyperconjugation. Further examples
Graphical Abstract
Figure 1: Fundamental characteristics of the C–F bond.
Figure 2: Incorporation of fluorine at the end of an alkyl chain.
Figure 3: Incorporation of fluorine into the middle of a linear alkyl chain.
Figure 4: Incorporation of fluorine across much, or all, of a linear alkyl chain.
Figure 5: Incorporation of fluorine into cycloalkanes.
Figure 6: Conformational effects of introducing fluorine into an ether (geminal to oxygen).
Figure 7: Conformational effects of introducing fluorine into an ether (vicinal to oxygen).
Figure 8: Effects of introducing fluorine into alcohols (and their derivatives).
Figure 9: Controlling the ring pucker of sugars through fluorination.
Figure 10: Controlling bond rotations outside the sugar ring through fluorination.
Figure 11: Effects of incorporating fluorine into amines.
Figure 12: Effects of incorporating fluorine into amine derivatives, such as amides and sulfonamides.
Figure 13: Effects of incorporating fluorine into organocatalysts.
Figure 14: Effects of incorporating fluorine into carbonyl compounds, focusing on the “carbon side.”
Figure 15: Fluoroproline-containing peptides and proteins.
Figure 16: Further examples of fluorinated linear peptides (besides fluoroprolines). For clarity, sidechains a...
Figure 17: Fluorinated cyclic peptides.
Figure 18: Fluorine-derived conformational control in sulfur-containing compounds.
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
- Rémy B. Teponno,
- Sara R. Noumeur and
- Marc Stadler
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- exhibit significant antimicrobial or cytotoxic activities upon testing [16]. This led us to hypothesize that possible chemical modification might enhance its biological activity. Therefore, the present research work aimed to investigate whether structural modifications could improve the biological
- groups, including an additional substitution on C-7, showed potent activity against nematodes. These acyl substituents, particularly the third cinnamoyl group on C-7, may significantly enhance the biological activity. This modification likely represents a key structural feature influencing its activity
- activity of this polyketide. Seven analogues of massarilactone D, compounds 2–8, were synthetized through acylation modifications aimed at enhancing the compound’s interactions with biological targets (Scheme 1). These acylated analogues were subsequently screened for their cytotoxicity against a panel of
Graphical Abstract
Scheme 1: Preparation of massarilactone D derivatives 2–8. Reagents and reactions conditions: a) (CH3CH2)3N/D...
Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions
- Xiao-Yang Bi,
- Xiao-Shuai Yang,
- Shan-Shan Chen,
- Jia-Jun Sui,
- Zhao-Nan Cai,
- Yong-Ming Chuan and
- Hong-Bo Qin
Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47
- , including insecticidal, antibacterial, anti-inflammatory, analgesic, and neurotrophic activities [3]. In 2013, Wang’s group isolated (±)-simonsol C from star anise, which features a unique 6/5/6 tricyclic benzofuran structure [4]. They found that it exhibits biological activity that promotes neuronal
Graphical Abstract
Figure 1: Representative sesquineolignan compounds.
Scheme 1: The first total synthesis of (±)-simonsol C by Banwell’s group.
Scheme 2: The second total synthesis of (±)-simonsol C developed by the Qin group.
Figure 2: Retrosynthetic analysis of (±)-simonsol C.
Scheme 3: Rapid access of the basic skeleton of (±)- simonsol C.
Scheme 4: Synthetic details to (±)-simonsol C.
Formaldehyde surrogates in multicomponent reactions
- Cecilia I. Attorresi,
- Javier A. Ramírez and
- Bernhard Westermann
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- and within shorter reaction times (Scheme 36). In recent years, several groups have applied these strategies to identify products with biological activity [94][95]. Representative examples are shown in Scheme 37. On the other hand, the van Leusen three-component reaction of an aryl-substituted tosyl
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.
Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles
- Constantine V. Milyutin,
- Andrey N. Komogortsev and
- Boris V. Lichitsky
Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44
- biological activity [1][2][3]. Among the numerous approaches using considered furanones as starting compounds the recyclization processes are of significant interest [4][5]. The important subclass of such synthetic methods is the interaction with nitrogen-containing reagents. In this case depending on the
- and allomaltol derivatives have the wide variety of biological activity [12][13][14][15][16]. This means that designing such hybrid products can significantly alter the pharmacological properties. Results and Discussion The starting compounds 1 were prepared from allomaltol employing a previously
Graphical Abstract
Scheme 1: Various examples of transformations of furanones.
Scheme 2: Interaction of starting 2H-furo[3,2-b]pyran-2-ones with diverse amines.
Scheme 3: Synthesis of enamines 4. Reaction conditions: 1a (1 mmol, 0.38 g), amine 2 (1.2 mmol), AcOH (3 mL).
Scheme 4: Synthesis of pyrazol-3-ones 8. Reaction conditions: 1 (1 mmol), hydrazine 7 (1.1 mmol), EtOH (5 mL)....
Scheme 5: Synthesis of pyrazol-3-one 10a.
Scheme 6: Synthesis of unsubstituted pyrazol-3-ones 10. Reaction conditions: 1 (1 mmol), hydrazine hydrate (2...
Scheme 7: Synthesis of isoxazolone 11. Reaction conditions: 1c (1 mmol, 0.30 g), hydroxylamine hydrochloride ...
Scheme 8: Proposed reaction mechanism.
Scheme 9: Synthesis of product 13. Reaction conditions: 8o (1 mmol, 0.37 g), pivaloyl chloride (3 mmol, 0.36 ...
Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides
- Ayesha Saeed,
- Shahana Ehsan,
- Muhammad Zia-ur-Rehman,
- Erin M. Marshall,
- Sandra Loesgen,
- Abdus Saleem,
- Simone Giovannuzzi and
- Claudiu T. Supuran
Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25
- evolves [3]. Complex chemical scaffolds with more than one protein-engaging functionality in a single molecule are advantageous for selectivity. This concept of synergistic compounds and complex chemical interactions helps to boost biological activity and prolongs the emergence of resistance in pathogens
Graphical Abstract
Figure 1: An overview of previously synthesized 1,2-benzothiazines [36-39].
Scheme 1: General scheme for the synthesis of pyrazolo-1,2-benzothiazine-N-aryl/benzyl/cyclohexylacetamide.
Figure 2: An example of contrasting 1H NMR signals for monoalkylated (7a) and dialkylated (7l) derivatives, (...
Red light excitation: illuminating photocatalysis in a new spectrum
- Lucas Fortier,
- Corentin Lefebvre and
- Norbert Hoffmann
Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22
- of the biological activity and to find biomedical applications, different releasing systems of this anion are developed. The peroxynitrite anion is formed by coupling of nitric oxide (NO) and the superoxide (O2•−). An efficient system has been developed to realize this reaction (Scheme 16) [74]. In a
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.
Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles
- Yujun Pang,
- Jinglan Yan,
- Nawaf Al-Maharik,
- Qian Zhang,
- Zeguo Fang and
- Dong Li
Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15
- as a vital pharmacophore in medicinal chemistry due to its special biological activity [11][12][13]. In particular, the tricyclic benzimidazole skeleton is ubiquitous in many bioactive compounds and therapeutic agents (Figure 1b) [14][15][16]. Recent studies have shown that fluorinated benzimidazole
Graphical Abstract
Figure 1: Selected examples containing tricyclic imidazole, CF2H or PhCF2 group.
Scheme 1: Strategies for the synthesis of difluoromethylated and difluoroarylmethylated tricyclic imidazoles.
Scheme 2: Substrate scope of the protocol. Reaction conditions: 1 (0.2 mmol), 2 (1.4 mmol), and PIDA (0.8 mmo...
Scheme 3: Control experiments and plausible mechanism.
Recent advances in organocatalytic atroposelective reactions
- Henrich Szabados and
- Radovan Šebesta
Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6
- the azodicarboxylate as crucial to forming hydrogen bonds with the organocatalyst. Benzylation of this nitrogen or substitution of just one of the carboxylate groups led to no product being observed. A series of naphthylindoles 71 was tested for potential biological activity and showed promising
- and stereoselectivities (85%, 90% ee, >95:5 E/Z). A biological activity investigation led to promising results in the case of one substrate displaying cytotoxicity towards several cancer cell lines. Organocatalytic enantioselective construction of axially chiral styrenes 175 and 177 was done utilizing
- enantiopurity at 130 °C for 48 h in toluene. Investigating the biological activity for a number of compounds, good cytotoxicity was reported for five kinds of cancer cells. The mechanistic study suggests that the indole ring of the substrate is having a crucial role in the reaction mechanism because replacing
Graphical Abstract
Scheme 1: Formation of axially chiral styrenes 3 via iminium activation.
Scheme 2: Synthesis of axially chiral 2-arylquinolines 6.
Scheme 3: Atroposelective intramolecular (4 + 2) annulation leading to aryl-substituted indolines.
Scheme 4: Atroposelective formation of biaryl via twofold aldol condensation.
Scheme 5: Strategy towards diastereodivergent formation of axially chiral oligonaphthylenes.
Scheme 6: Atroposelective formation of chiral biaryls based on a Michael/Henry domino reaction.
Scheme 7: Organocatalytic Michael/aldol cascade followed by oxidative aromatization.
Scheme 8: Atroposelective formation of C(sp2)–C(sp3) axially chiral compounds.
Scheme 9: NHC-catalyzed synthesis of axially chiral styrenes 26.
Scheme 10: NHC-catalyzed synthesis of biaxial chiral pyranones.
Scheme 11: Formation of bridged biaryls with eight-membered lactones.
Scheme 12: The NHC-catalyzed (3 + 2) annulation of urazoles 37 and ynals 36.
Scheme 13: NHC-catalyzed synthesis of axially chiral 4‑aryl α‑carbolines 41.
Scheme 14: NHC-catalyzed construction of N–N-axially chiral pyrroles and indoles.
Scheme 15: NHC-catalyzed oxidative Michael–aldol cascade.
Scheme 16: NHC-catalyzed (4 + 2) annulation for the synthesis of benzothiophene-fused biaryls.
Scheme 17: NHC-catalyzed desymmetrization of N-aryl maleimides.
Scheme 18: NHC-catalyzed deracemization of biaryl hydroxy aldehydes 55a–k into axially chiral benzonitriles 56a...
Scheme 19: NHC-catalyzed desymmetrization of 2-aryloxyisophthalaldehydes.
Scheme 20: NHC-catalyzed DKR of 2-arylbenzaldehydes 62.
Scheme 21: Atroposelective biaryl amination.
Scheme 22: CPA-catalyzed atroposelective amination of 2-anilinonaphthalenes.
Scheme 23: Atroposelective DKR of naphthylindoles.
Scheme 24: CPA-catalyzed kinetic resolution of binaphthylamines.
Scheme 25: Atroposelective amination of aromatic amines with diazodicarboxylates.
Scheme 26: Atroposelective Friedländer heteroannulation.
Scheme 27: CPA-catalyzed formation of axially chiral 4-arylquinolines.
Scheme 28: CPA-catalyzed Friedländer reaction of arylketones with cyclohexanones.
Scheme 29: CPA-catalyzed atroposelective Povarov reaction.
Scheme 30: Atroposelective CPA-catalyzed Povarov reaction.
Scheme 31: Paal–Knorr formation of axially chiral N-pyrrolylindoles and N-pyrrolylpyrroles.
Scheme 32: Atroposelective Paal–Knorr reaction leading to N-pyrrolylpyrroles.
Scheme 33: Atroposelective Pictet–Spengler reaction of N-arylindoles with aldehydes.
Scheme 34: Atroposelective Pictet–Spengler reaction leading to tetrahydroisoquinolin-8-ylanilines.
Scheme 35: Atroposelective formation of arylindoles.
Scheme 36: CPA-catalyzed arylation of naphthoquinones with indolizines.
Scheme 37: Atroposelective reaction of o-naphthoquinones.
Scheme 38: CPA-catalyzed formation of axially chiral arylquinones.
Scheme 39: CPA-catalyzed axially chiral N-arylquinones.
Scheme 40: Atroposelective additions of bisindoles to isatin-based 3-indolylmethanols.
Scheme 41: CPA-catalyzed synthesis of axially chiral arylindolylindolinones.
Scheme 42: CPA-catalyzed reaction between bisindoles and ninhydrin-derived 3-indoylmethanols.
Scheme 43: Atroposelective reaction of bisindoles and isatin-derived imines.
Scheme 44: CPA-catalyzed formation of axially chiral bisindoles.
Scheme 45: Atroposelective reaction of 2-naphthols with alkynylhydroxyisoindolinones.
Scheme 46: CPA-catalyzed reaction of indolylnaphthols with propargylic alcohols.
Scheme 47: Atroposelective formation of indolylpyrroloindoles.
Scheme 48: Atroposelective reaction of indolylnaphthalenes with alkynylnaphthols.
Scheme 49: CPA-catalyzed addition of naphthols to alkynyl-2-naphthols and 2-naphthylamines.
Scheme 50: CPA-catalyzed formation of axially chiral aryl-alkene-indoles.
Scheme 51: CPA-catalyzed formation of axially chiral styrenes.
Scheme 52: Atroposelective formation of alkenylindoles.
Scheme 53: Atroposelective formation of axially chiral arylquinolines.
Scheme 54: Atroposelective (3 + 2) cycloaddition of alkynylindoles with azonaphthalenes.
Scheme 55: CPA-catalyzed formation of axially chiral 3-(1H-benzo[d]imidazol-2-yl)quinolines.
Scheme 56: Atroposelective cyclization of 3-(arylethynyl)-1H-indoles.
Scheme 57: Atroposelective three-component heteroannulation.
Scheme 58: CPA-catalyzed formation of arylbenzimidazols.
Scheme 59: CPA-catalyzed reaction of N-naphthylglycine esters with nitrosobenzenes.
Scheme 60: CPA-catalyzed formation of axially chiral N-arylbenzimidazoles.
Scheme 61: CPA-catalyzed formation of axially chiral arylbenzoindoles.
Scheme 62: CPA-catalyzed formation of pyrrolylnaphthalenes.
Scheme 63: CPA-catalyzed addition of naphthols and indoles to nitronaphthalenes.
Scheme 64: Atroposelective reaction of heterobiaryl aldehydes and aminobenzamides.
Scheme 65: Atroposelective cyclization forming N-arylquinolones.
Scheme 66: Atroposelective formation of 9H-carbazol-9-ylnaphthalenes and 1H-indol-1-ylnaphthalene.
Scheme 67: CPA-catalyzed formation of pyrazolylnaphthalenes.
Scheme 68: Atroposelective addition of diazodicarboxamides to azaborinephenols.
Scheme 69: Catalytic formation of axially chiral arylpyrroles.
Scheme 70: Atroposelective coupling of 1-azonaphthalenes with 2-naphthols.
Scheme 71: CPA-catalyzed formation of axially chiral oxindole-based styrenes.
Scheme 72: Atroposelective electrophilic bromination of aminonaphthoquinones.
Scheme 73: Atroposelective bromination of dienes.
Scheme 74: CPA-catalyzed formation of axially chiral 5-arylpyrimidines.
Scheme 75: Atroposelective hydrolysis of biaryloxazepines.
Scheme 76: Atroposelective opening of dinaphthosiloles.
Scheme 77: Atroposelective reduction of naphthylenals.
Scheme 78: Atroposelective allylic substitution with 2-naphthols.
Scheme 79: Atroposelective allylic alkylation with phosphinamides.
Scheme 80: Atroposelective allylic substitution with aminopyrroles.
Scheme 81: Atroposelective allylic substitution with aromatic sulfinamides.
Scheme 82: Atroposelective sulfonylation of naphthylynones.
Scheme 83: Squaramide-catalyzed reaction of alkynyl-2-naphthols with 5H-oxazolones.
Scheme 84: Formation of axially chiral styrenes via sulfonylative opening of cyclopropanols.
Scheme 85: Atroposelective organo-photocatalyzed sulfonylation of alkynyl-2-naphthols.
Scheme 86: Thiourea-catalyzed atroposelective cyclization of alkynylnaphthols.
Scheme 87: Squaramide-catalyzed formation of axially chiral naphthylisothiazoles.
Scheme 88: Atroposelective iodo-cyclization catalyzed by squaramide C69.
Scheme 89: Squaramide-catalyzed formation of axially chiral oligoarenes.
Scheme 90: Atroposelective ring-opening of cyclic N-sulfonylamides.
Scheme 91: Thiourea-catalyzed kinetic resolution of naphthylpyrroles.
Scheme 92: Atroposelective ring-opening of arylindole lactams.
Scheme 93: Atroposelective reaction of 1-naphthyl-2-tetralones and diarylphosphine oxides.
Scheme 94: Atroposelective reaction of iminoquinones with indoles.
Scheme 95: Kinetic resolution of binaphthylalcohols.
Scheme 96: DKR of hydroxynaphthylamides.
Scheme 97: Atroposelective N-alkylation with phase-transfer catalyst C75.
Scheme 98: Atroposelective allylic substitution via kinetic resolution of biarylsulfonamides.
Scheme 99: Atroposelective bromo-functionalization of alkynylarenes.
Scheme 100: Sulfenylation-induced atroposelective cyclization.
Scheme 101: Atroposelective O-sulfonylation of isochromenone-indoles.
Scheme 102: NHC-catalyzed atroposelective N-acylation of anilines.
Scheme 103: Peptide-catalyzed atroposelective ring-opening of lactones.
Scheme 104: Peptide-catalyzed coupling of 2-naphthols with quinones.
Scheme 105: Atroposelective nucleophilic aromatic substitution of fluoroarenes.
Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina
- Shin-ichiro Kurimoto,
- Kouta Inoue,
- Taito Ohno and
- Takaaki Kubota
Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267
- discovery of an additional psammaplysin derivative, ceratinadin G (1) (Figure 1). This paper details the isolation, structural elucidation, and biological activity of compound 1. Results and Discussion The marine sponge Pseudoceratina sp., collected in Okinawa, Japan, was initially extracted with MeOH
Graphical Abstract
Figure 1: Structures of ceratinadin G (1) and psammaplysin F (2).
Figure 2: Selected 2D NMR correlations for ceratinadin G (1).
Figure 3: ECD spectra of ceratinadin G (1) and psammaplysin F (2) in MeOH.
Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction
- Cesia M. Aguilar-Morales,
- América A. Frías-López,
- Nadia V. Emilio-Velázquez,
- Alejandro Islas-Jácome,
- Angelica Judith Granados-López,
- Jorge Gustavo Araujo-Huitrado,
- Yamilé López-Hernández,
- Hiram Hernández-López,
- Luis Chacón-García,
- Jesús Adrián López and
- Carlos J. Cortés-García
Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256
- -enter into the catalytic cycle. On the other hand, the sulfonyl group in its sulfonamide form is typically associated with antibacterial activity. However, it has been little studied the sulfonyl group regarding biological activity when attached to the indole nitrogen. Although scarce, some recent
Graphical Abstract
Scheme 1: Synthetic approaches to obtain the 1,5-disubstituted tetrazole-indole system and our synthetic appr...
Scheme 2: High-order multicomponent reaction for the synthesis of 1,5-disubstituted tetrazol-methanesulfonyli...
Scheme 3: Plausible reaction mechanism for the synthesis of target molecules 18a–n.
Figure 1: Differential effect of the 1,5-disubstituted tetrazole-indole hybrid compounds 18a–j on proliferati...
Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts
- Ritu Mamgain,
- Kokila Sakthivel and
- Fateh V. Singh
Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243
- in aryl-transfer processes, DIAS are frequently employed as photoinitiators for cationic polymerizations [31][32][33], Lewis acids [34], oxidants [35][36] and in the field of macromolecular chemistry [37][38]. Additionally, biological activity is also exhibited by iodonium salts, often due to their
Graphical Abstract
Figure 1: Various structures of iodonium salts.
Scheme 1: Αrylation of α-fluoroacetoacetamides 5 to α-aryl-α-fluoroacetoacetamides 7 and α-fluoroacetamides 8...
Scheme 2: Proposed mechanism for the arylation of α-fluoroacetoacetamides 5 to α-aryl-α-fluoroacetoacetamides ...
Scheme 3: α-Arylation of α-nitro- and α-cyano derivatives of α-fluoroacetamides 9 employing unsymmetrical DAI...
Scheme 4: Synthesis of α,α-difluoroketones 13 by reacting α,α-difluoro-β-keto acid esters 11 with aryl(TMP)io...
Scheme 5: Coupling reaction of arynes generated by iodonium salts 6 and arynophiles 14 for the synthesis of t...
Scheme 6: Metal-free arylation of quinoxalines 17 and quinoxalinones 19 with DAISs 16.
Scheme 7: Transition-metal-free, C–C cross-coupling of 2-naphthols 21 to 1-arylnapthalen-2-ols 22 employing d...
Scheme 8: Arylation of vinyl pinacol boronates 23 to trans-arylvinylboronates 24 in presence of hypervalent i...
Scheme 9: Light-induced selective arylation at C2 of quinoline N-oxides 25 and pyridine N-oxides 28 in the pr...
Scheme 10: Plaussible mechanism for the light-induced selective arylation of N-heterobiaryls.
Scheme 11: Photoinduced arylation of heterocycles 31 with the help of diaryliodonium salts 16 activated throug...
Scheme 12: Arylation of MBH acetates 33 with DIPEA and DAIRs 16.
Scheme 13: Aryl sulfonylation of MBH acetates 33 with DABSO and diphenyliodonium triflates 16.
Scheme 14: Synthesis of oxindoles 37 from N-arylacrylamides 36 and diaryliodonium salts 26.
Scheme 15: Mechanically induced N-arylation of amines 38 using diaryliodonium salts 16.
Scheme 16: o-Fluorinated diaryliodonium salts 40-mediated diarylation of amines 38.
Scheme 17: Proposed mechanism for the diarylation of amines 38 using o-fluorinated diaryliodonium salts 40.
Scheme 18: Ring-opening difunctionalization of aliphatic cyclic amines 41.
Scheme 19: N-Arylation of amino acid esters 44 using hypervalent iodonium salts 45.
Scheme 20: Regioselective N-arylation of triazole derivatives 47 by hypervalent iodonium salts 48.
Scheme 21: Regioselective N-arylation of tetrazole derivatives 50 by hypervalent iodonium salt 51.
Scheme 22: Selective arylation at nitrogen and oxygen of pyridin-2-ones 53 by iodonium salts 16 depending on t...
Scheme 23: N-Arylation using oxygen-bridged acyclic diaryliodonium salt 56.
Scheme 24: The successive C(sp2)–C(sp2)/O–C(sp2) bond formation of naphthols 58.
Scheme 25: Synthesis of diarylethers 62 via in situ generation of hypervalent iodine salts.
Scheme 26: O-Arylated galactosides 64 by reacting protected galactosides 63 with hypervalent iodine salts 16 i...
Scheme 27: Esterification of naproxen methyl ester 65 via formation and reaction of naproxen-containing diaryl...
Scheme 28: Etherification and esterification products 72 through gemfibrozil methyl ester-derived diaryliodoni...
Scheme 29: Synthesis of iodine containing meta-substituted biaryl ethers 74 by reacting phenols 61 and cyclic ...
Scheme 30: Plausible mechanism for the synthesis of meta-functionalized biaryl ethers 74.
Scheme 31: Intramolecular aryl migration of trifluoromethane sulfonate-substituted diaryliodonium salts 75.
Scheme 32: Synthesis of diaryl ethers 80 via site-selective aryl migration.
Scheme 33: Synthesis of O-arylated N-alkoxybenzamides 83 using aryl(trimethoxyphenyl)iodonium salts 82.
Scheme 34: Synthesis of aryl sulfides 85 from thiols 84 using diaryliodonium salts 16 in basic conditions.
Scheme 35: Base-promoted synthesis of diarylsulfoxides 87 via arylation of general sulfinates 86.
Scheme 36: Plausible mechanism for the arylation of sulfinates 86 via sulfenates A to give diaryl sulfoxides 87...
Scheme 37: S-Arylation reactions of aryl or heterocyclic thiols 88.
Scheme 38: Site-selective S-arylation reactions of cysteine thiol groups in 91 and 94 in the presence of diary...
Scheme 39: The selective S-arylation of sulfenamides 97 using diphenyliodonium salts 98.
Scheme 40: Plausible mechanism for the synthesis of sulfilimines 99.
Scheme 41: Synthesis of S-arylxanthates 102 by reacting DAIS 101 with potassium alkyl xanthates 100.
Figure 2: Structured of the 8-membered and 4-membered heterotetramer I and II.
Scheme 42: S-Arylation by diaryliodonium cations 103 using KSCN (104) as a sulfur source.
Scheme 43: S-Arylation of phosphorothioate diesters 107 through the utilization of diaryliodonium salts 108.
Scheme 44: Transfer of the aryl group from the hypervalent iodonium salt 108 to phosphorothioate diester 107.
Scheme 45: Synthesis of diarylselenides 118 via diarylation of selenocyanate 115.
Scheme 46: Light-promoted arylation of tertiary phosphines 119 to quaternary phosphonium salts 121 using diary...
Scheme 47: Arylation of aminophosphorus substrate 122 to synthesize phosphine oxides 123 using aryl(mesityl)io...
Scheme 48: Reaction of diphenyliodonium triflate (16) with DMSO (124) via thia-Sommelet–Hauser rearrangement.
Scheme 49: Synthesis of biaryl compounds 132 by reacting diaryliodonium salts 131 with arylhydroxylamines 130 ...
Scheme 50: Synthesis of substituted indazoles 134 and 135 from N-hydroxyindazoles 133.
Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids
- Andrey N. Komogortsev,
- Constantine V. Milyutin and
- Boris V. Lichitsky
Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217
- ; 1,1′-carbonyldiimidazole; 3-hydroxypyran-4-ones; tetronic acid; Introduction 3-Hydroxypyran-4-one derivatives are an important class of heterocyclic compounds widely represented in various naturally occurring sources [1][2][3][4]. Products of this type demonstrate a broad range of biological activity
Graphical Abstract
Scheme 1: Synthesis of tetronic acid derivatives.
Scheme 2: Synthesis of amide derivatives 3.
Scheme 3: Synthesis of target tetronic acids 4a. aReaction conditions: 3a (1 mmol), CDI (0.49 g, 3 mmol), DBU...
Figure 1: The X-ray crystal structure of compound 4a (CCDC 2352876).
Scheme 4: Proposed reaction mechanism for the formation of products 4.
Scheme 5: Synthesis of derivatization products 7 and 9.
Figure 2: The X-ray crystal structure of compound 7 (CCDC 2352878).
Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose
- Olivier Lessard,
- Mathilde Grosset-Magagne,
- Paul A. Johnson and
- Denis Giguère
Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208
- chiral halides: F, Cl, Br, I) [19]. Only a handful of natural product syntheses have been reported [20][21], despite the promising biological activity of these unique inter-halides [22]. For our part, we recently reported the synthesis of contiguous inter-halide-bearing stereocenters using a Chiron
Graphical Abstract
Figure 1: Synthesis of trihalogenated pyrans: a) Chiron approach to multivicinal inter-halide derived from al...
Scheme 1: Synthesis of halogenated talopyranose analogues 13–15, and 17 that include a 2,3-cis, 3,4-cis relat...
Figure 2: Direct comparison of 19F resonances of halogenated talose analogues 12–15 (19F NMR; 470 MHz, CDCl3)....
Figure 3: X-ray analysis of compound 13–15, 17, and α-ᴅ-talose 18. ORTEP diagram showing 50% thermal ellipsoi...
Figure 4: Packing arrangement of compound compound 15; a) View down the b axis; b) proposed intermolecular in...
Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments
- Daria A. Burmistrova,
- Andrey Galustyan,
- Nadezhda P. Pomortseva,
- Kristina D. Pashaeva,
- Maxim V. Arsenyev,
- Oleg P. Demidov,
- Mikhail A. Kiskin,
- Andrey I. Poddel’sky,
- Nadezhda T. Berberova and
- Ivan V. Smolyaninov
Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202
- heteroatoms (nitrogen, sulfur, selenium, tellurium, etc.) as well as redox-active functional groups allows one to vary significantly the biological activity of such compounds. Heterocyclic molecular blocks are widely used in medicinal chemistry [12]. Thiazole, oxadiazole, triazole, imidazole, and other
- [25]. A feature of mercapto-substituted heterocycles is the possibility of their existence in two tautomeric forms: thiol or thione [26][27]. The ability to tautomeric transformations affects their biological activity and allows the use of these molecular blocks to design compounds with different
- view of studying their potential biological activity. This work aimed to obtain new multifunctional catechols containing pharmacologically active heterocyclic fragments such as thiazole, 1,3,4-oxadiazole, 1,2,4-triazole, and pyridine. We decided to use a non-hydrolyzable thioether group as a bridging
Graphical Abstract
Scheme 1: Synthesis of catechol-containing compounds 1–9.
Figure 1: The X-ray structure of catechol 5 (the thermal ellipsoids of 50% probability). The hydrogen atoms e...
Figure 2: The X-ray structures of catechols 6 (a) and 8 (b) (the thermal ellipsoids of 50% probability). The ...
Figure 3: Fragment of the pack of catechol 5 in crystal (the H-bonds and π–π interactions are shown as dotted...
Figure 4: The interactions in pair of independent molecules A and B of 6 in crystal 6·0.5CH3CN (the H-bonds a...
Figure 5: Fragment of the pack of catechol 8 in crystal (the H-bonds and π–π interactions are shown as dotted...
Scheme 2: Electrochemical transformations of compounds 1–3.
Figure 6: The CV curve of 2 at the potential range from −0.50 to 1.60 V (CH3CN, GC electrode, Ag/AgCl/KCl(sat...
Figure 7: The CV curves of 3 at the potential ranges from –0.5 to 1.2 V (curve 1); from –0.5 to 2.0 V (curve ...
Figure 8: The CV curves of 7 at the potential ranges from –0.5 to 1.3 V (curve 1); from –0.5 to 1.8 V (curve ...
Scheme 3: Proposed mechanism of an electrooxidation of compounds 6–8.
Figure 9: The level of TBARS in rat liver homogenates in vitro, in the presence of compounds 1–9, Trolox, and...
Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers
- Andreas Wiest and
- Pavel Kielkowski
Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199
- -crosslinker, is attached synthetically to the basic scaffold (Figure 2A) [28][29][30][31][32]. However, this requires a structure–activity relationship (SAR) screening to ensure that the selected NP retains biological activity after modification. The term probe is further used to unite such NPs and active
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.
Deuterated reagents in multicomponent reactions to afford deuterium-labeled products
- Kevin Schofield,
- Shayna Maddern,
- Yueteng Zhang,
- Grace E. Mastin,
- Rachel Knight,
- Wei Wang,
- James Galligan and
- Christopher Hulme
Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195
- flexibility [8]. Indeed, early incorporation of deuterium during hit generation may negate the need for late-stage C–H functionalization which often requires strong external oxidants or affords products with significantly lower biological activity [25][26][27]. Thus, eight MCRs were evaluated for D-reagent
Graphical Abstract
Scheme 1: Competitive examples of D2-benzylamine formation via phenyl-nitriles.
Scheme 2: Proposed tentative mechanism of [D3]-formamide formation via modified Leuckart–Wallach reaction wit...
Scheme 3: Ugi-4CR products: no deuterium scrambling observed.
Scheme 4: Ugi-3CR products. No deuterium scrambling observed.
Scheme 5: Ugi-azide reaction products, no deuterium scrambling observed.
Scheme 6: Passerini products, no deuterium scrambling observed. aWater was used as solvent.
Scheme 7: Strecker reaction products (precursors to [D1]-α-amino acids), no deuterium scrambling was observed...
Scheme 8: Biginelli reaction products, no deuterium scrambling was observed. Six site-specific deuterated Big...
Scheme 9: GBB reaction products, no deuterium scrambling was observed. aA 70% [D2]-isocyanide was used in 7a ...
Scheme 10: Modified Hantzsch pyridine synthesis to afford 1,4-dihydropyridines. No deuterium scrambling was ob...
Scheme 11: CYP3A4 mediated dehydrogenation of dihydropyridines.
gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu4NBF4 or electrogenerated acid
- Mizuki Yamaguchi,
- Hiroki Shimao,
- Kengo Hamasaki,
- Keiji Nishiwaki,
- Shigenori Kashimura and
- Kouichi Matsumoto
Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194
- also been proposed [19][20]. Thus, the synthesis of fluorinated compounds is an active research field. Among these compounds, skeletons bearing CF2 units are important [21][22][23][24], because such molecules can change the physical properties and biological activity. They can also serve as building
Graphical Abstract
Figure 1: gem-Difluorination of carbon–carbon triple bonds. Selected examples from (1) to (5), and this work ...
Scheme 1: gem-Difluorination promoted by electrogenerated acids (method B).
Scheme 2: Generation and accumulation of EGA followed by the reaction with 1a for 2a.
Scheme 3: Plausible reaction mechanism.
Natural resorcylic lactones derived from alternariol
- Joachim Podlech
Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187
- biological activity was determined for these compounds. Pestauvicomorpholine A (34) is an exceptional hybrid metabolite with fusion of a polyketide-derived resorcylic lactone and the steroid dihydroergosterol, which was isolated from the fungus Pestalotiopsis uvicola [174]. Its structure was determined by
- NMR spectroscopy; no biological activity could be elucidated. Sabilactone (35) was isolated from the plant Sabina vulgaris Antoine [195][196], but no further information could be revealed for this compound. The strong resemblance of autumnariol (36) and autumnariniol (37) with alternariol and 4
- measured and calculated ECD spectra. No biological activity was determined for this compound [163]. Alternate A (64) was isolated from A. alternata [161]. The constitution of the compound was elucidated, but neither its absolute nor relative configuration could be determined. Alternate A was tested for its
Graphical Abstract
Figure 1: Examples of compounds covered in this review categorized in six sub-classes (see text).
Figure 2: Examples of compounds not covered in this review.
Figure 3: Wrongly assigned and thus obsolete structures (details will be discussed in the respective chapters...
Figure 4: Alternariol with the correct IUPAC numbering and an occasionally used numbering based on the biphen...
Figure 5: Alternariol O-methyl ethers.
Figure 6: Alternariol O-glycosides.
Figure 7: Alternariol O-acetates and O-sulfates.
Figure 8: 2-Hydroxy- and 4-hydroxy-substituted alternariol and its O-methyl ethers.
Figure 9: Chloro- and amino-substituted alternariol and its O-methyl ethers.
Figure 10: Presumed alternariol derivatives with non-canonical substitution pattern.
Figure 11: Alternariol derivatives with the 1-methyl group hydroxylated.
Figure 12: Verrulactones: pseudo-dimeric derivatives of altertenuol and related compounds.
Figure 13: Biaryls formed by reductive lactone opening and/or by decarboxylation.
Figure 14: Altenuene and its diastereomers.
Figure 15: 9-O-Demethylated altenuene diastereomers.
Figure 16: Acetylated and methylated altenuene diastereomers.
Figure 17: Altenuene diastereomers modified with lactic acid, pyruvic acid, or acetone.
Figure 18: Neoaltenuene and related compounds.
Figure 19: Dehydroaltenusin and its derivatives.
Scheme 1: Equilibrium of dehydroaltenusin in polar solvents [278].
Figure 20: Further quinoid derivatives.
Figure 21: Dehydroaltenuenes.
Figure 22: Complex aggregates containing dehydroaltenuene substructures and related compounds.
Figure 23: Dihydroaltenuenes.
Figure 24: Altenuic acids and related compounds.
Figure 25: Cyclopentane- and cyclopentene-fused derivatives.
Figure 26: Cyclopentenone-fused derivatives.
Figure 27: Spiro-fused derivatives and a related ring-opened derivative.
Figure 28: Lactones-fused and lactone-substituted derivatives.
Scheme 2: Biosynthesis of alternariol [324].
Scheme 3: Biosynthesis of alternariol and its immediate successors with the genes involved in the respective ...
Scheme 4: Presumed formation of altenuene and its diastereomers and of botrallin.
Scheme 5: Presumed formation of altenuic acids and related compounds.
Scheme 6: A selection of plausible biosynthetic paths to cyclopenta-fused metabolites. (No stereochemistry is...
Scheme 7: Biomimetic synthesis of alternariol (1) by Harris and Hay [66].
Scheme 8: Total synthesis of alternariol (1) by Subba Rao et al. using a Diels–Alder approach [34].
Scheme 9: Total synthesis of alternariol (1) using a Suzuki strategy by Koch and Podlech [62], improved by Kim et...
Scheme 10: Total synthesis of alternariol (1) using an intramolecular biaryl coupling by Abe et al. [63].
Scheme 11: Total synthesis of altenuene (54) and isoaltenuene (55) by Podlech et al. [249].
Scheme 12: Total synthesis of neoaltenuene (69) by Podlech et al. [35].
Scheme 13: Total synthesis of TMC-264 (79) by Tatsuta et al. [185].
Scheme 14: Total synthesis of cephalosol (99) by Koert et al. [304].
O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization
- Kateryna V. Dil and
- Vitalii A. Palchykov
Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184
- biotargets (pathogens, species, diseases) for new synthesized compounds. If we focus on high levels of biological activity probability (80% and above), the following pathogens and diseases may be potential areas of interest: Alphis gossypii, Tripomastigote Chagas, Candida albicans, Tcruzi amastigota
Graphical Abstract
Scheme 1: The general Biginelli reaction (A) and examples of DHMP (B) and thiopyran-1,1-dioxide (C) containin...
Figure 1: Number of aryl-substituted Biginelli-type products and publications as analyzed by Reaxys database....
Scheme 2: Scope of the obtained Biginelli products 2a–q.
Scheme 3: Synthesis of SO2-containing enastron analogue 2r.
Scheme 4: Postmodification of the Biginelli product 2a.
Figure 2: Distribution of compounds 2a–r, 3–7 (log P (y)–MW (x)) through LLAMA software. The chemical structu...
Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps
- Ignaz Betcke,
- Alissa C. Götzinger,
- Maryna M. Kornet and
- Thomas J. J. Müller
Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178
- ; one-pot reactions; pyrazole; Introduction Pyrazoles and 1,2-diazoles [1] have received considerable interest in the past years. Although they are rarely found in nature [2], their spectrum of biological activity is remarkably broad, leading to numerous applications in pharmaceutical chemistry [3][4
Graphical Abstract
Scheme 1: Consecutive three-component synthesis of pyrazoles 1 via in situ-formed 1,3-diketones 2 [44].
Scheme 2: Consecutive three-component synthesis of 4-ethoxycarbonylpyrazoles 5 via SmCl3-catalyzed acylation ...
Scheme 3: Consecutive four-component synthesis of 1-(thiazol-2-yl)pyrazole-3-carboxylates 8 [51].
Scheme 4: Three-component synthesis of thiazolylpyrazoles 17 via in situ formation of acetoacetylcoumarins 18 ...
Scheme 5: Consecutive pseudo-four-component and four-component synthesis of pyrazoles 21 from sodium acetylac...
Scheme 6: Consecutive three-component synthesis of 1-substituted pyrazoles 24 from boronic acids, di(Boc)diim...
Scheme 7: Consecutive three-component synthesis of N-arylpyrazoles 25 via in situ formation of aryl-di(Boc)hy...
Scheme 8: Consecutive three-component synthesis of 1,3,4-substituted pyrazoles 27 and 28 from methylhydrazine...
Scheme 9: Consecutive three-component synthesis of 4-allylpyrazoles 32 via oxidative allylation of 1,3-dicarb...
Scheme 10: Pseudo-five-component synthesis of tris(pyrazolyl)methanes 35 [61].
Scheme 11: Pseudo-three-component synthesis of 5-(indol-3-yl)pyrazoles 39 from 1,3,5-triketones 38 [64].
Scheme 12: Three-component synthesis of thiazolylpyrazoles 43 [65].
Scheme 13: Three-component synthesis of triazolo[3,4-b]-1,3,4-thiadiazin-3-yl substituted 5-aminopyrazoles 47 [67]....
Scheme 14: Consecutive three-component synthesis of 5-aminopyrazoles 49 via formation of β-oxothioamides 50 [68].
Scheme 15: Synthesis of 3,4-biarylpyrazoles 52 from aryl halides, α-bromocinnamaldehyde, and tosylhydrazine vi...
Scheme 16: Consecutive three-component synthesis of 3,4-substituted pyrazoles 57 from iodochromones 55 by Suzu...
Scheme 17: Pseudo-four-component synthesis of pyrazolyl-2-pyrazolines 59 by ring opening/ring closing cyclocon...
Scheme 18: Consecutive three-component synthesis of pyrazoles 61 [77].
Scheme 19: Three-component synthesis of pyrazoles 62 from malononitrile, aldehydes, and hydrazines [78-90].
Scheme 20: Four-component synthesis of pyrano[2,3-c]pyrazoles 63 [91].
Scheme 21: Three-component synthesis of persubstituted pyrazoles 65 from aldehydes, β-ketoesters, and hydrazin...
Scheme 22: Three-component synthesis of pyrazol-4-carbodithioates 67 [100].
Scheme 23: Regioselective three-component synthesis of persubstituted pyrazoles 68 catalyzed by ionic liquid [...
Scheme 24: Consecutive three-component synthesis of 4-halopyrazoles 69 and anellated pyrazoles 70 [102].
Scheme 25: Three-component synthesis of 2,2,2-trifluoroethyl pyrazole-5-carboxylates 72 [103].
Scheme 26: Synthesis of pyrazoles 75 in a one-pot process via carbonylative Heck coupling and subsequent cycli...
Scheme 27: Copper-catalyzed three-component synthesis of 1,3-substituted pyrazoles 76 [105].
Scheme 28: Pseudo-three-component synthesis of bis(pyrazolyl)methanes 78 by ring opening-ring closing cyclocon...
Scheme 29: Three-component synthesis of 1,4,5-substituted pyrazoles 80 [107].
Scheme 30: Consecutive three-component synthesis of 3,5-bis(fluoroalkyl)pyrazoles 83 [111].
Scheme 31: Consecutive three-component synthesis of difluoromethanesulfonyl-functionalized pyrazole 88 [114].
Scheme 32: Consecutive three-component synthesis of perfluoroalkyl-substituted fluoropyrazoles 91 [115].
Scheme 33: Regioselective consecutive three-component synthesis of 1,3,5-substituted pyrazoles 93 [116].
Scheme 34: Three-component synthesis of pyrazoles 96 mediated by trimethyl phosphite [117].
Scheme 35: One-pot synthesis of pyrazoles 99 via Liebeskind–Srogl cross-coupling/cyclocondensation [118].
Scheme 36: Synthesis of 1,3,5-substituted pyrazoles 101 via domino condensation/Suzuki–Miyaura cross-coupling ...
Scheme 37: Consecutive three-component synthesis of 1,3,5-trisubstituted pyrazoles 102 and 103 by Sonogashira ...
Scheme 38: Polymer analogous consecutive three-component synthesis of pyrazole-based polymers 107 [132].
Scheme 39: Synthesis of 1,3,5-substituted pyrazoles 108 by sequentially Pd-catalyzed Kumada–Sonogashira cycloc...
Scheme 40: Consecutive four-step one-pot synthesis of 1,3,4,5-substituted pyrazoles 110 [137].
Scheme 41: Four-component synthesis of pyrazoles 113, 115, and 117 via Sonogashira coupling and subsequent Suz...
Scheme 42: Consecutive four- or five-component synthesis for the preparation of 4-pyrazoly-1,2,3-triazoles 119...
Scheme 43: Four-component synthesis of pyrazoles 121 via alkynone formation by carbonylative Pd-catalyzed coup...
Scheme 44: Preparation of 3-azulenyl pyrazoles 124 by glyoxylation, decarbonylative Sonogashira coupling, and ...
Scheme 45: Four-component synthesis of a 3-indoloylpyrazole 128 [147].
Scheme 46: Two-step synthesis of 5-acylpyrazoles 132 via glyoxylation-Stephen–Castro sequence and subsequent c...
Scheme 47: Copper on iron mediated consecutive three-component synthesis of 3,5-substituted pyrazoles 136 [150].
Scheme 48: Consecutive three-component synthesis of 3-substituted pyrazoles 141 by Sonogashira coupling and su...
Scheme 49: Consecutive three-component synthesis of pyrazoles 143 initiated by Cu(I)-catalyzed carboxylation o...
Scheme 50: Consecutive three-component synthesis of benzamide-substituted pyrazoles 146 starting from N-phthal...
Scheme 51: Consecutive three-component synthesis of 1,3,5-substituted pyrazoles 148 [156].
Scheme 52: Three-component synthesis of 4-ninhydrin-substituted pyrazoles 151 [158].
Scheme 53: Consecutive four-component synthesis of 4-(oxoindol)-1-phenylpyrazole-3-carboxylates 155 [159].
Scheme 54: Three-component synthesis of pyrazoles 160 [160].
Scheme 55: Consecutive three-component synthesis of pyrazoles 165 [162].
Scheme 56: Consecutive three-component synthesis of 3,5-disubstituted and 3-substituted pyrazoles 168 and 169 ...
Scheme 57: Three-component synthesis of 3,4,5-substituted pyrazoles 171 via 1,3-dipolar cycloaddition of vinyl...
Scheme 58: Three-component synthesis of pyrazoles 173 and 174 from aldehydes, tosylhydrazine, and vinylidene c...
Scheme 59: Three-component synthesis of pyrazoles 175 from glyoxyl hydrates, tosylhydrazine, and electron-defi...
Scheme 60: Pseudo-four-component synthesis of pyrazoles 177 from glyoxyl hydrates, tosylhydrazine, and aldehyd...
Scheme 61: Consecutive three-component synthesis of pyrazoles 179 via Knoevenagel-cycloaddition sequence [179].
Scheme 62: Three-component synthesis of 5-dimethylphosphonate substituted pyrazoles 182 from aldehydes, the Be...
Scheme 63: Consecutive three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 185 from al...
Scheme 64: Three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 187 from aldehydes, the...
Scheme 65: Three-component synthesis of 5-diethylphosphonate/5-phenylsulfonyl substituted pyrazoles 189 from a...
Scheme 66: Pseudo-three-component synthesis of 3-(dimethyl phosphonate)-substituted pyrazoles 190 [185].
Scheme 67: Three-component synthesis of 3-trifluoromethylpyrazoles 193 [186].
Scheme 68: Consecutive three-component synthesis of 5-stannyl-substituted 4-fluoropyrazole 197 [191,192].
Scheme 69: Pseudo-three-component synthesis of 3,5-diacyl-4-arylpyrazoles 199 [195].
Scheme 70: Three-component synthesis of pyrazoles 204 via nitrilimines [196].
Scheme 71: Three-component synthesis of 1,3,5-substituted pyrazoles 206 via formation of nitrilimines and sali...
Scheme 72: Pseudo four-component synthesis of pyrazoles 209 from acetylene dicarboxylates 147, hydrazonyl chlo...
Scheme 73: Consecutive three-component synthesis of pyrazoles 213 via syndnones 214 [200].
Scheme 74: Consecutive three-component synthesis of pyrazoles 216 via in situ-formed diazomethinimines 217 [201].
Scheme 75: Consecutive three-component synthesis of 3-methylthiopyrazoles 219 from aldehydes, hydrazine, and 1...
Scheme 76: Three-component synthesis of 1,3,5-substituted pyrazoles 220 from aldehydes, hydrazines, and termin...
Scheme 77: Three-component synthesis of 1,3,4,5-substituted pyrazoles 222 from aldehydes, hydrazines, and DMAD ...
Scheme 78: Pseudo three-component synthesis of pyrazoles 224 from sulfonyl hydrazone and benzyl acrylate under...
Scheme 79: Titanium-catalyzed consecutive four-component synthesis of pyrazoles 225 via enamino imines 226 [211]. a...
Scheme 80: Titanium-catalyzed three-component synthesis of pyrazoles 227 via enhydrazino imine complex interme...
Scheme 81: Pseudo-three-component synthesis of pyrazoles 229 via Glaser coupling of terminal alkynes and photo...
Scheme 82: Copper(II)acetate-mediated three-component synthesis of pyrazoles 232 [216].
Scheme 83: Copper-catalyzed three-component synthesis of 1,3,4-substituted pyrazole 234 from oxime acetates, a...
Scheme 84: Three-component synthesis of 3-trifluoroethylpyrazoles 239 [218].
Scheme 85: Pseudo-three-component synthesis of 1,4-bisulfonyl-substituted pyrazoles 242 [219].
Scheme 86: Three-component synthesis of 4-hydroxypyrazole 246 [221].
Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles
- Ivan Lyutin,
- Vasilisa Krivovicheva,
- Grigory Kantin and
- Dmitry Dar’in
Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164
- derivatives (mainly amides) exhibit various types of biological activity, among which the following can be highlighted: inhibition of β-lactamases [4][5], antitubercular properties [6], antiproliferative and antibacterial activity [7], herbicidal properties [8][9], inhibition of neutral amino acid transporter
Graphical Abstract
Scheme 1: Synthetic routes to 2-oxoazetidine-3-carboxylic acid derivatives.
Scheme 2: Scope of diazotetramic acids 1 thermolysis in the presence of various nucleophiles. PMP = p-methoxy...
Scheme 3: Negative results with several N-, O-, and C-nucleophiles and with diazo reagent 1m.
Scheme 4: Preparation of acids 4 by hydrogenolysis of benzyl esters and examples of acid 4a amidation.
The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)
- Cristina Martini,
- Muhammad Idham Darussalam Mardjan and
- Andrea Basso
Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162
- compounds. Dömling et al. [50] also reported the synthesis of N-edited guanine derivatives. Different drugs display the guanine motif, fundamental for its biological activity is a triad HBA–HBD–HBD (HBA = hydrogen bond acceptor, HBD = hydrogen bond donor) included in its structure. The authors propose a one
Graphical Abstract
Scheme 1: Mechanism of the GBB reaction.
Scheme 2: Comparison of the performance of Sc(OTf)3 with some RE(OTf)3 in a model GBB reaction. Conditions: a...
Scheme 3: Comparison of the performance of various Brønsted acid catalysts in the synthesis of GBB adduct 6. ...
Scheme 4: Synthesis of Brønsted acidic ionic liquid catalyst 7. Conditions: a) neat, 60 °C, 24 h; b) TfOH, DC...
Scheme 5: Aryliodonium derivatives as organic catalysts in the GBB reaction. In the box the proposed binding ...
Scheme 6: DNA-encoded GBB reaction in micelles made of amphiphilic polymer 13. Conditions: a) 13 (50 equiv), ...
Scheme 7: GBB reaction catalyzed by cyclodextrin derivative 14. Conditions: a) 14 (1 mol %), water, 100 °C, 4...
Scheme 8: Proposed mode of activation of CALB. a) activation of the substrates; b) activation of the imine; c...
Scheme 9: One-pot GBB reaction–Suzuki coupling with a bifunctional hybrid biocatalyst. Conditions: a) Pd(0)-C...
Scheme 10: GBB reaction employing 5-HMF (23) as carbonyl component. Conditions: a) TFA (20 mol %), EtOH, 60 °C...
Scheme 11: GBB reaction with β-C-glucopyranosyl aldehyde 26. Conditions: a) InCl3 (20 mol %), MeOH, 70 °C, 2–3...
Scheme 12: GBB reaction with diacetylated 5-formyldeoxyuridine 29, followed by deacetylation of GBB adduct 30....
Scheme 13: GBB reaction with glycal aldehydes 32. Conditions: a) HFIP, 25 °C, 2–4 h.
Scheme 14: Vilsmeier–Haack formylation of 6-β-acetoxyvouacapane (34) and subsequent GBB reaction. Conditions: ...
Scheme 15: GBB reaction of 4-formlyl-PCP 37. Conditions: a) HOAc or HClO4, MeOH/DCM (2:3), rt, 3 d.
Scheme 16: GBB reaction with HexT-aldehyde 39. Conditions: a) 39 (20 nmol) and amidine (20 μmol), MeOH, rt, 6 ...
Scheme 17: GBB reaction of 2,4-diaminopirimidine 41. Conditions: a) Sc(OTf)3 (20 mol %), MeCN, 120 °C (MW), 1 ...
Scheme 18: Synthesis of N-edited guanine derivatives from 3,6-diamine-1,2,4-triazin-5-one 44. Conditions: a) S...
Scheme 19: Synthesis of 2-aminoimidazoles 49 by a Mannich-3CR followed by a one-pot intramolecular oxidative a...
Scheme 20: On DNA Suzuki–Miyaura reaction followed by GBB reaction. Conditions: a) CsOH, sSPhos-Pd-G2; b) AcOH...
Scheme 21: One-pot cascade synthesis of 5-iminoimidazoles. Conditions: a) Na2SO4, DMF, 220 °C (MW).
Scheme 22: GBB reaction of 5-amino-1H-imidazole-4-carbonile 57. Conditions: a) HClO4 (5 mol %), MeOH, rt, 24 h....
Scheme 23: One-pot cascade synthesis of indole-imidazo[1,2,a]pyridine hybrids. In blue the structural motif in...
Scheme 24: One-pot cascade synthesis of fused polycyclic indoles 67 or 69 from indole-3-carbaldehyde. Conditio...
Scheme 25: One-pot cascade synthesis of linked- and bridged polycyclic indoles from indole-2-carbaldehyde (70)...
Scheme 26: One-pot cascade synthesis of pentacyclic dihydroisoquinolines (X = N or CH). In blue the structural...
Scheme 27: One-pot stepwise synthesis of imidazopyridine-fused benzodiazepines 85. Conditions: a) p-TsOH (20 m...
Scheme 28: One-pot stepwise synthesis of benzoxazepinium-fused imidazothiazoles 89. Conditions: a) Yb(OTf)3 (2...
Scheme 29: One-pot stepwise synthesis of fused imidazo[4,5,b]pyridines 95. Conditions: a) HClO4, MeOH, rt, ove...
Scheme 30: Synthesis of heterocyclic polymers via the GBB reaction. Conditions: a) p-TsOH, EtOH, 70 °C, 24 h.
Scheme 31: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 32: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 33: GBB-like multicomponent reaction towards the synthesis of benzothiazolpyrroles (X = S) and benzoxaz...
Scheme 34: GBB-like multicomponent reaction towards the formation of imidazo[1,2,a]pyridines. Conditions: a) I2...
Scheme 35: Post-functionalization of GBB products via Ugi reaction. Conditions a) HClO4, DMF, rt, 24 h; b) MeO...
Scheme 36: Post-functionalization of GBB products via Click reaction. Conditions: a) solvent-free, 150 °C, 24 ...
Scheme 37: Post-functionalization of GBB products via cascade alkyne–allene isomerization–intramolecular nucle...
Scheme 38: Post-functionalization of GBB products via metal-catalyzed intramolecular N-arylation. In red and b...
Scheme 39: Post-functionalization of GBB products via isocyanide insertion (X = N or CH). Conditions: a) HClO4...
Scheme 40: Post-functionalization of GBB products via intramolecular nucleophilic addition to nitriles. Condit...
Scheme 41: Post-functionalization of GBB products via Pictet–Spengler cyclization. Conditions: a) 4 N HCl/diox...
Scheme 42: Post-functionalization of GBB products via O-alkylation. Conditions: a) TFA (20 mol %), EtOH, 120 °...
Scheme 43: Post-functionalization of GBB products via macrocyclization (X = -CH2CH2O-, -CH2-, -(CH2)4-). Condi...
Figure 1: Antibacterial activity of GBB-Ugi adducts 113 on both Gram-negative and Gram-positive strains.
Scheme 44: GBB multicomponent reaction using trimethoprim as the precursor. Conditions: a) Yb(OTf)3 or Y(OTf)3...
Figure 2: Antibacterial activity of GBB adducts 152 against MRSA and VRE; NA = not available.
Figure 3: Antibacterial activity of GBB adduct 153 against Leishmania amazonensis promastigotes and amastigot...
Figure 4: Antiviral and anticancer evaluation of the GBB adducts 154a and 154b. In vitro antiproliferative ac...
Figure 5: Anticancer activity of the GBB-furoxan hybrids 145b, 145c and 145d determined through antiprolifera...
Scheme 45: Synthesis and anticancer activity of the GBB-gossypol conjugates. Conditions: a) Sc(OTf)3 (10 mol %...
Figure 6: Anticancer activity of polyheterocycles 133a and 136a against human neuroblastoma. Clonogenic assay...
Figure 7: Development of GBB-adducts 158a and 158b as PD-L1 antagonists. HTRF assays were carried out against...
Figure 8: Development of imidazo[1,2-a]pyridines and imidazo[1,2-a]pyrazines as TDP1 inhibitors. The SMM meth...
Figure 9: GBB adducts 164a–c as anticancer through in vitro HDACs inhibition assays. Additional cytotoxic ass...
Figure 10: GBB adducts 165, 166a and 166b as anti-inflammatory agents through HDAC6 inhibition; NA = not avail...
Scheme 46: GBB reaction of triphenylamine 167. Conditions: a) NH4Cl (10 mol %), MeOH, 80 °C (MW), 1 h.
Scheme 47: 1) Modified GBB-3CR. Conditions: a) TMSCN (1.0 equiv), Sc(OTf)3 (0.2 equiv), MeOH, 140 °C (MW), 20 ...
Scheme 48: GBB reaction to assemble imidazo-fused heterocycle dimers 172. Conditions: a) Sc(OTf)3 (20 mol %), ...
Figure 11: Model compounds 173 and 174, used to study the acid/base-triggered reversible fluorescence response...
