Search for "toxicity" in Full Text gives 375 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65
Graphical Abstract
Figure 1: Natural products and synthetic medicinal compounds containing a 2-pyrrolidinone subunit.
Scheme 1: Synthesis of 4-[1-(4-methoxybenzyl)amino]ethylidene-1,5-disubstituted pyrrolidine-2,3-diones 3a–e.
Scheme 2: Synthesis of 4-(1-methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones 5a–e.
Scheme 3: Proposed mechanism for the reaction between 4-[1-(4-methoxybenzyl)amino]ethylidene-1,5-disubstitute...
Figure 2: The molecular structure of 5a, showing the atom-labelling scheme and displacement ellipsoids at the...
Figure 3: The bioavailability radar of studied compounds 5a–e.
Figure 4: The interactions of potential drugs 5a–c in the active site of enzyme iNOS.
Figure 5: The interactions of potential drugs 5d and 5e and control drug (DEX) in the active site of enzyme i...
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
Graphical Abstract
Scheme 1: Representative transition-metal catalysis for allylic substitution.
Scheme 2: Formation of stereogenic centers in copper-catalyzed allylic alkylation reactions.
Scheme 3: Copper-mediated, stereospecific SN2-selective allylic substitution through retentive transmetalatio...
Scheme 4: ZnCl2-promoted stereospecific SN2' allylic substitution of secondary alkylcopper species via sequen...
Scheme 5: Temperature and time-dependent configurational stability of chiral secondary organocopper species.
Scheme 6: DFT analysis of B–C bond lengths in various boronate complexes and correlation with reactivity.
Scheme 7: Copper-catalyzed stereospecific allylic alkylation of secondary alkylboronic esters via tert-butyll...
Scheme 8: Copper-catalyzed stereospecific allylic alkylation of chiral tertiary alkylboronic esters via adama...
Scheme 9: DFT-calculated energy surface for boron-to-copper transmetalation of either the tert-butyl group or...
Scheme 10: CuH-catalyzed enantioselective allylic substitution and postulated catalytic cycle.
Scheme 11: CuH-catalyzed enantioselective allylic substitution of vinylarenes.
Scheme 12: CuH-catalyzed stereoselective allylic substitution of vinylboronic esters.
Scheme 13: (a) Generation of chiral copper species via enantioselective CuH addition to vinylBpin. (b) Regardi...
Scheme 14: CuH-catalyzed enantioselective allylic substitution of 1‐trifluoromethylalkenes with 18-crown-6.
Scheme 15: CuH-catalyzed enantioselective allylic substitution of terminal alkynes.
Scheme 16: Copper-catalyzed enantiotopic-group-selective allylic substitution of 1,1-diborylalkanes.
Scheme 17: (a) Computational and (b) experimental studies to elucidate the mechanistic details of the enantiot...
Scheme 18: Copper-catalyzed regio-, diastereo- and enantioselective allylic substitution of 1,1-diborylalkanes....
Scheme 19: (a) Experimental and (b) computational studies to understand the stereoselectivities in oxidative a...
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
Graphical Abstract
Figure 1: Representation of an antibody–drug conjugate. The antibody shown in this figure is from https://www...
Figure 2: a. Photoredox catalytic cycles; b. absorption spectrum of photosensitizers. Therapeutic window indi...
Figure 3: Graph representing the average number of publications focusing on photoredox chemistry applied to p...
Figure 4: Schematic procedure developed by Sato et al. on histidine photoinduced modification. The antibody s...
Figure 5: Schematic procedure of the divergent method developed by Sato et al. on histidine/tyrosine photoind...
Figure 6: Schematic procedure developed by Bräse et al. on photoinduced disulfide rebridging method.
Figure 7: Schematic procedure developed by Lang et al. on a photoinduced dual nickel photoredox-catalyzed app...
Figure 8: Schematic of the procedure developed by Chang et al. on photoinduced high affinity IgG Fc-binding s...
Figure 9: Potential advantages of photoredox chemistry for bioconjugation applied to antibodies. The antibody...
Figure 10: Representation of the photoinduced control of the DAR. The antibody shown in this figure is from ht...
Figure 11: Representation of a photoinduced control of multi-payloads ADC strategy. The antibody shown in this...
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
Graphical Abstract
Scheme 1: Features of the ideal reaction (redrawn from P. A. Wender et al. [1]).
Scheme 2: Some of the most popular MCRs with formaldehyde as the carbonyl component.
Scheme 3: Ugi reaction under a catalyzed electro-oxidation process using TEMPO (2,2,6,6-tetramethyl-1-piperid...
Scheme 4: Examples of different products obtained by MCRs in which DMSO serves as -SCH3 source.
Scheme 5: Mechanism of the decomposition of DMSO under acidic or thermal conditions. a) In situ generation of...
Scheme 6: Povarov multicomponent reaction to quinolines.
Scheme 7: Example of the Povarov reaction with formaldehyde with a julolidine derivative as main product.
Scheme 8: Povarov multicomponent reaction to quinoline derivatives I and II using DMSO as formaldehyde surrog...
Scheme 9: Example of a Povarov three-component reaction with change of catalyst, yielding regioisomer III. In...
Scheme 10: The Povarov three-component reactions carried out under acidic catalysis to afford quinoline regios...
Scheme 11: Different MCR routes involving DMSO to synthesize complex heterocycles such as diarylpyridines and ...
Scheme 12: Pyrazole synthesis by a three-component reaction using DMSO as a source of a C-1 unit.
Scheme 13: Three-component reactions for the synthesis of aliphatic heterocycles 13 and 14 using DMSO as a for...
Scheme 14: Proposed mechanism for the 3CR between homoallylic amines, disulfides, and DMSO.
Scheme 15: Mannich-type reaction using DMSO as formaldehyde surrogate.
Scheme 16: Mechanism for the 3CR-Mannich-type reaction between aryl ketone 18, saccharine (19), and DMSO. The ...
Scheme 17: Mannich-type reaction using DMSO as formaldehyde surrogate and under oxidative activation.
Scheme 18: Three-component reaction between an indazole, a carboxylic acid, and DMSO.
Scheme 19: Amine–aldehyde–alkyne (AAA) coupling reaction and plausible mechanism.
Scheme 20: AHA coupling for the synthesis of propargylamines using dihalomethanes as C1 building blocks.
Scheme 21: AHA coupling using CH2Cl2 as both solvent and methylene source.
Scheme 22: Examples of propargylamines synthesized under catalytic AHA protocols.
Scheme 23: Proposed mechanism for the synthesis of propargylamines using dichloromethane as a C1 source.
Scheme 24: Mechanism proposed for the generation of the aminal intermediate E by Buckley et al. [68].
Scheme 25: Pudovic and Kabachnik–Fields reactions for the synthesis of α-aminophosphonates.
Scheme 26: a) Abramov side reaction that generates α-hydroxy phosphonate as a byproduct during the Kabachnik-F...
Scheme 27: Catalyst-free three component reaction to afford α-amino phosphorus product 35 using 1,1-dihaloalka...
Scheme 28: a) Proposed mechanism for the three-component reaction of dichloromethane, amine and phosphorus com...
Scheme 29: Ugi-ammonia strategy using HMTA as a formaldehyde surrogate.
Scheme 30: Glyoxylate and its derivatives as C1 building blocks.
Scheme 31: The Groebke–Blackburn–Bienaymé multicomponent reaction (GBB) and its mechanism.
Scheme 32: a) Byproducts in the GBB multicomponent reaction (GBB) when formaldehyde is used as the carbonyl co...
Scheme 33: Possible regioisomers in the GBB multicomponent reaction when formaldehyde is used as the carbonyl ...
Scheme 34: The multicomponent GBB reaction yields 2-unsubstituted 3-aminoimidazo heterocycles 42a using MP-gly...
Scheme 35: GBB multicomponent reaction to 2-unsubstituted 3-amino imidazo heterocycles 42a using glyoxylic aci...
Scheme 36: GBB reaction using glyoxylic acid immobilized on silica as formaldehyde surrogate.
Scheme 37: Bioactive products synthesized by the GBB reaction using glyoxylic acid.
Scheme 38: van Leusen three-component reaction to imidazoles.
Scheme 39: Side reaction during the synthesis of imidazoles with formaldehyde as the carbonyl compound.
Scheme 40: Optimization of the van Leusen three component reaction to 1,4-disubstituted imidazoles 43 using gl...
Scheme 41: Application of the Sisko strategy [96] for the synthesis of CB1 receptor antagonist compounds [97].
Scheme 42: Side reaction, when NH4OH is used as amine component.
Scheme 43: Ugi-type adducts with the ester moiety and the acidic CH to be used for post-cyclization sequences.
Scheme 44: Ugi/cycloisomerization process to pyrrolones 51, butenolides 52, and pyrroline 53.
Scheme 45: Radical cyclization reactions from Ugi adducts promoted by TEMPO.
Scheme 46: Hydrolysis and decarboxylation reactions to products with incorporation of a C1 unit of ethyl glyox...
Scheme 47: One-step synthetic route to pyrrolones 60 using phenylglyoxal.
Scheme 48: Ugi-pseudo-Knoevenagel-pseudo-Dieckmann cascade sequence for the synthesis of fused heterocycles.
Scheme 49: Ugi-pseudo-Knoevenagel reaction from ethyl glyoxylate.
Beilstein J. Org. Chem. 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, 200–216, doi:10.3762/bjoc.21.12
Graphical Abstract
Scheme 1: Formation of isocyanates and amidated arenes from dioxazolones.
Scheme 2: Copper-catalyzed synthesis of δ-lactams via open-shell copper nitrenoid transfer. aCuBr (10 mol %) ...
Figure 1: Proposed reaction pathway for the copper-catalyzed synthesis of δ-lactams from dioxazolones.
Scheme 3: Copper(II)-catalyzed synthesis of 1,2,4-triazole derivatives.
Figure 2: Proposed reaction mechanism for the copper-catalyzed synthesis of 1,2,4-triazole analogues from dio...
Scheme 4: Copper(I)-catalyzed synthesis of N-acyl amidines from dioxazolones, acetylenes, and amines. aPerfor...
Figure 3: Proposed reaction mechanism for the copper(I)-catalyzed synthesis of N-acyl amidines.
Scheme 5: Preparation of N-arylamides from dioxazolones and boronic acids using a copper salt.
Figure 4: Proposed reaction pathway for the copper-mediated synthesis of N-arylamides from dioxazolones.
Scheme 6: Copper-catalyzed preparation of N-acyl iminophosphoranes from dioxazolones.
Figure 5: Proposed reaction pathway for the copper-catalyzed synthesis of N-acyl iminophosphoranes from dioxa...
Scheme 7: Copper-catalyzed synthesis of N-acyl sulfenamides. a1.0 equiv of 18 and 2.0 equiv of 19 were used. b...
Figure 6: Proposed reaction mechanism for the copper-catalyzed S-amidation of thiols.
Scheme 8: Copper-catalyzed asymmetric hydroamidation of vinylarenes. a4 mol % + 2 mol % catalyst was used. b4...
Figure 7: Proposed reaction mechanism for the copper-catalyzed hydroamidation of vinylarenes.
Scheme 9: Copper-catalyzed anti-Markovnikov hydroamidation of alkynes.
Figure 8: Proposed reaction mechanism for the copper-catalyzed amidation of alkynes.
Scheme 10: Copper-catalyzed preparation of primary amides through N–O bond reduction using reducing agent.
Figure 9: Proposed catalytic cycle for the copper-catalyzed reduction of dioxazolones.
Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9
Graphical Abstract
Figure 1: General mechanisms of traditional and radical-mediated cross-coupling reactions.
Figure 2: Types of electrocatalysis (using anodic oxidation).
Figure 3: Recent developments and features of electrochemical copper catalysis.
Figure 4: Scheme and proposed mechanism for Cu-catalyzed alkynylation and annulation of benzamide.
Figure 5: Scheme and proposed mechanism for Cu-catalyzed asymmetric C–H alkynylation.
Figure 6: Scheme for Cu/TEMPO-catalyzed C–H alkenylation of THIQs.
Figure 7: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical enantioselective cyanation of b...
Figure 8: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical asymmetric heteroarylcyanation ...
Figure 9: Scheme and proposed mechanism for Cu-catalyzed enantioselective regiodivergent cross-dehydrogenativ...
Figure 10: Scheme and proposed mechanism for Cu/Ni-catalyzed stereodivergent homocoupling of benzoxazolyl acet...
Figure 11: Scheme and proposed mechanism for Cu-catalyzed electrochemical amination.
Figure 12: Scheme and proposed mechanism for Cu-catalyzed electrochemical azidation of N-arylenamines and annu...
Figure 13: Scheme and proposed mechanism for Cu-catalyzed electrochemical halogenation.
Figure 14: Scheme and proposed mechanism for Cu-catalyzed asymmetric cyanophosphinoylation of vinylarenes.
Figure 15: Scheme and proposed mechanism for Cu/Co dual-catalyzed asymmetric hydrocyanation of alkenes.
Figure 16: Scheme and proposed mechanism for Cu-catalyzed electrochemical diazidation of olefins.
Figure 17: Scheme and proposed mechanism for Cu-catalyzed electrochemical azidocyanation of alkenes.
Figure 18: Scheme and proposed mechanism for Cu-catalyzed electrophotochemical asymmetric decarboxylative cyan...
Figure 19: Scheme and proposed mechanism for electrocatalytic Chan–Lam coupling.
Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7
Graphical Abstract
Figure 1: Plausible general catalytic activation for ionic or radical mechanisms.
Scheme 1: Synthesis of α-aminonitriles 1.
Scheme 2: Synthesis of β-amino ketone or β-amino ester derivatives 3.
Scheme 3: Synthesis of 1-(α-aminoalkyl)-2-naphthol derivatives 4.
Scheme 4: Synthesis of thioaminals 5.
Scheme 5: Synthesis of aryl- or amine-containing alkanes 6 and 7.
Scheme 6: Synthesis of 1-aryl-2-sulfonamidopropanes 8.
Scheme 7: Synthesis of α-substituted propargylamines 10.
Scheme 8: Synthesis of N-propargylcarbamates 11.
Scheme 9: Synthesis of (E)-vinyl sulfones 12.
Scheme 10: Synthesis of o-halo-substituted aryl chalcogenides 13.
Scheme 11: Synthesis of α-aminophosphonates 14.
Scheme 12: Synthesis of unsaturated furanones and pyranones 15–17.
Scheme 13: Synthesis of substituted dihydropyrimidines 18.
Scheme 14: Regioselective synthesis of 1,4-dihydropyridines 20.
Scheme 15: Synthesis of tetrahydropyridines 21.
Scheme 16: Synthesis of furoquinoxalines 22.
Scheme 17: Synthesis of 2,4-substituted quinolines 23.
Scheme 18: Synthesis of cyclic ether-fused tetrahydroquinolines 24.
Scheme 19: Practical route for 1,2-dihydroisoquinolines 25.
Scheme 20: Synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives 26.
Scheme 21: Synthesis of polysubstituted pyrroles 27.
Scheme 22: Enantioselective synthesis of polysubstituted pyrrolidines 30 directed by the copper complex 29.
Scheme 23: Synthesis of 4,5-dihydropyrazoles 31.
Scheme 24: Synthesis of 2 arylisoindolinones 32.
Scheme 25: Synthesis of imidazo[1,2-a]pyridines 33.
Scheme 26: Synthesis of isoxazole-linked imidazo[1,2-a]azines 35.
Scheme 27: Synthesis of 2,3-dihydro-1,2,4-triazoles 36.
Scheme 28: Synthesis of naphthopyrans 37.
Scheme 29: Synthesis of benzo[g]chromene derivatives 38.
Scheme 30: Synthesis of naphthalene annulated 2-aminothiazoles 39, piperazinyl-thiazoloquinolines 40 and thiaz...
Scheme 31: Synthesis of furo[3,4-b]pyrazolo[4,3-f]quinolinones 42.
Scheme 32: Synthesis of spiroindoline-3,4’-pyrano[3,2-b]pyran-4-ones 43.
Scheme 33: Synthesis of N-(α-alkoxy)alkyl-1,2,3-triazoles 44.
Scheme 34: Synthesis of 4-(α-tetrasubstituted)alkyl-1,2,3-triazoles 45.
Beilstein J. Org. Chem. 2024, 20, 3274–3280, doi:10.3762/bjoc.20.271
Graphical Abstract
Figure 1: Giese reaction: Radical addition on olefins with an electron-withdrawing group (EWG) followed by a ...
Figure 2: Alkyl bromide and Dha derivative scope. Reaction conditions: Dha derivative (0.5 mmol), alkyl bromi...
Figure 3: Scaled-up reaction. Reaction conditions: Dha derivative (2.2 mmol), alkyl bromide (5.4 mmol), tris(...
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, 2891–2920, doi:10.3762/bjoc.20.243
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.
Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236
Graphical Abstract
Figure 1: Some biologically active compounds and organic fluorophores containing the imidazo[1,2-a]pyrimidine...
Figure 2: Existing approaches to imidazo[1,2-a]pyrimidines.
Scheme 1: Reaction of 2-aminoimidazole (1) with N-substituted maleimides (2) and N-arylitaconimides (3).
Scheme 2: Plausible synthetic routes for the interaction of N-substituted maleimides 2 with 2-aminoimidazole (...
Scheme 3: Plausible synthetic routes for the interaction of or N-arylitaconimides 3 with 2-aminoimidazole (1)....
Figure 3: Key correlations observed in the NOESY and HMBC spectra of the products 4d and 5d.
Scheme 4: Results of MEP calculations for the reaction of N-phenylmaleimide (2a) with 2-aminoimidazole (1).
Scheme 5: Results of MEP calculations for the reaction of N-phenylithaconimide (3a) with 2-aminoimidazole (1)....
Figure 4: Structures of imidazo[1,2-a]pyrimidines selected for docking and voriconazole selected for comparis...
Figure 5: (A) Position of the (S)-isomer of compound 4e in the active site of CYP51 after molecular dockinga....
Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218
Graphical Abstract
Figure 1: Aminoquinazolines and our new target molecules.
Scheme 1: Synthesis of the desired targets 4.
Figure 2: Target molecules 4 prepared with the yields for the last step.
Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209
Graphical Abstract
Figure 1: Functional molecules containing a substituted pyrrolidine core.
Scheme 1: A) Our previous report on N-alkenylamide cyclizations. B) An overview of the present work.
Scheme 2: Calculated mechanism for the cyclization of amide 3a optimized at the B3LYP/ 6-31+G(d,p) level of t...
Scheme 3: Scope of cyclization reaction.
Scheme 4: Reactions of di- and trisubstituted alkene substrates.
Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207
Graphical Abstract
Figure 1: Examples of trifluoromethoxylated drugs.
Scheme 1: Proposed mechanism of the reaction and 19F NMR of the DDPYOCF3/PhSeBr mixture.
Scheme 2: Phenylseleno trifluoromethoxylation of various alkenes. Yields determined by 19F NMR spectroscopy w...
Scheme 3: Degradation of 2a under acidic conditions.
Scheme 4: Radical deselenylation of 2. Yields determined by 19F NMR spectroscopy with PhCF3 as internal stand...
Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201
Graphical Abstract
Scheme 1: The position of homoallylic amines in the landscape of alkaloid and nitrogen compounds syntheses.
Scheme 2: 3,3’-Diaryl-BINOL-catalysed asymmetric organocatalytic allylation of acylimines [24].
Scheme 3: Aminophenol-catalysed reaction between N-phosphinoylimines and pinacol allylboronic ester. Imine sc...
Scheme 4: Asymmetric geranylation and prenylation of indoles catalysed by (R)- or (S)-3,3’-dibromo-BINOL [25]. aA...
Scheme 5: (R)-3,3’-Di(3,5-di(trifluoromethyl)phenyl-BINOL-catalysed asymmetric geranylation and prenylation o...
Scheme 6: Microwave-induced one-pot asymmetric allylation of in situ-formed arylimines, catalysed by (R)-3,3’...
Scheme 7: Microwave-induced one-pot asymmetric allylation of in situ-formed arylimines, catalysed by (R)-3,3’...
Scheme 8: Kinetic resolution of chiral secondary allylboronates [15,30].
Scheme 9: (E)-Stereospecific asymmetric α-trifluoromethylallylation of cyclic imines and hydrazones [31].
Scheme 10: Hosomi–Sakurai-type allylation of in situ-formed N-Fmoc aldimines [32].
Figure 1: Two different pathways for the Hosomi–Sakurai reaction of allyltrimethylsilane with N-Fmoc aldimine...
Scheme 11: Chiral squaramide-catalysed hydrogen bond-assisted chloride abstraction–allylation of N-carbamoyl α...
Figure 2: The pyrrolidine unit gem-methyl group conformational control in the squaramide-based catalyst [34].
Figure 3: The energetic difference between the transition states of the two proposed modes of the reaction (SN...
Scheme 12: One-pot preparation procedure for oxazaborolidinium ion (COBI) 63 [37].
Scheme 13: Chiral oxazaborolidinium ion (COBI)-catalysed allylation of N-(2-hydroxy)phenylimines with allyltri...
Scheme 14: The two-step N-(2-hydroxy)phenyl group deprotection procedure [37].
Scheme 15: Low-temperature (−40 °C) NMR experiments evidencing the reversible formation of the active COBI–imi...
Figure 4: Two computed reaction pathways for the COBI-catalysed Strecker reaction (TS1 identical to allylatio...
Scheme 16: Highly chemoselective and stereospecific synthesis of γ- and γ,δ-substituted homoallylic amines by ...
Scheme 17: Catalytic cycle for the three-component allylation with HBD/πAr–Ar catalyst [39].
Scheme 18: Reactivity of model electrophiles [39].
Scheme 19: HBD/πAr–Ar catalyst rational design and optimisation [39].
Scheme 20: Scope of the three-component HBD/πAr–Ar-catalysed reaction [39].
Scheme 21: Limitations of the HBD/πAr–Ar-catalysed reaction [39].
Scheme 22: Asymmetric chloride-directed dearomative allylation of in situ-generated N-acylquinolinium ions, ca...
Scheme 23: Chiral phosphoric acid-catalysed aza-Cope rearrangement of in situ-formed N-α,α’-diphenyl-(α’’-ally...
Scheme 24: Tandem (R)-VANOL-triborate-catalysed asymmetric aza-Cope rearrangement of in situ-formed aldimines ...
Scheme 25: (S)-TRIP-catalysed enantioconvergent aza-Cope rearrangement of β-formyl amides, substrate scope [43]. a...
Scheme 26: (S)-TRIP-catalysed enantioconvergent aza-Cope rearrangement of β-formyl amides 16–19, amide and all...
Scheme 27: Synthetic applications of homoallylic N-benzophenone imine products 131 [43].
Scheme 28: Chiral organocatalysed addition of 2,2,2-trifluoroethyl ketimines to isatin-derived Morita–Baylis–H...
Scheme 29: Chiral chinchona-derived amine-catalysed reaction between isatin-based Morita–Baylis–Hilman carbona...
Scheme 30: (R)-VAPOL-catalysed hydrogen atom transfer deracemisation [45].
Scheme 31: Chiral PA-catalysed [1,3]-rearrangement of ene-aldimines [46].
Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187
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].
Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184
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...
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, 1955–1966, doi:10.3762/bjoc.20.171
Graphical Abstract
Scheme 1: 1,2-Difluoroethylene synthesis from HFO-1123.
Scheme 2: 1,2-Difluoroethylene synthesis from CFC-112 and HCFC-132.
Scheme 3: 1,2-Difluoroethylene synthesis from HFC-143.
Scheme 4: 1,2-Difluoroethylene synthesis from HCFC-142 via HCFC-142a.
Scheme 5: 1,2-Difluoroethylene synthesis from CFO-1112.
Scheme 6: 1,2-Difluoroethylene synthesis from 1,2-dichloroethylene.
Scheme 7: 1,2-Difluoroethylene synthesis from perfluoropropyl vinyl ether.
Scheme 8: Deuteration reaction of 1,2-difluoroethylene.
Scheme 9: Halogen addition to 1,2-difluoroethylene.
Scheme 10: Hypohalite addition to 1,2-difluoroethylene.
Scheme 11: N-Bromobis(trifluoromethyl)amine addition to 1,2-difluoroethylene.
Scheme 12: N-Chloroimidobis(sulfonyl fluoride) addition to 1,2-difluoroethylene.
Scheme 13: Trichlorosilane addition to 1,2-difluoroethylene.
Scheme 14: SF5Br addition to 1,2-difluoroethylene.
Scheme 15: PCl3/O2 addition to 1,2-difluoroethylene.
Scheme 16: Reaction of tetramethyldiarsine with 1,2-difluoroethylene.
Scheme 17: Reaction of trichlorofluoromethane with 1,2-difluoroethylene.
Scheme 18: Addition of perfluoroalkyl iodides to 1,2-difluoroethylene.
Scheme 19: Cyclopropanation of 1,2-difluoroethylene.
Scheme 20: Diels–Alder reaction of 1,2-difluoroethylene and hexachlorocyclopentadiene.
Scheme 21: Cycloaddition reaction of 1,2-difluoroethylene and fluorinated ketones.
Scheme 22: Cycloaddition reaction of 1,2-difluoroethylene and perfluorinated aldehydes.
Scheme 23: Photochemical cycloaddition of 1,2-difluoroethylene and hexafluorodiacetyl.
Scheme 24: Reaction of 1,2-difluoroethylene with difluorosilylene.
Scheme 25: Reaction of 1,2-difluoroethylene with aryl iodides.
Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163
Graphical Abstract
Scheme 1: Description of the 2-heteroarylethylamine scope of the present review featuring appropriate heteroa...
Scheme 2: 2-Aminoethylpyridine derivatives with therapeutic activity.
Scheme 3: 2-Aminoethylfuran derivatives with therapeutic activity.
Scheme 4: 2-Aminoethylthiophene derivatives with therapeutic activity, part 1.
Scheme 5: 2-Aminoethylthiophene derivatives with therapeutic activity, part 2.
Scheme 6: 2-Aminoethylthiophene derivatives with therapeutic activity, part 3.
Scheme 7: 2-Aminoethylpyrrole derivatives with therapeutic activity.
Scheme 8: Histamine metabolic pathway.
Scheme 9: 2-Aminoethylimidazole derivatives with therapeutic activity, part 1. Krel is referred as histamine ...
Scheme 10: Conformationally restricted 2-aminoethylimidazole derivatives with therapeutic activity, part 2.
Scheme 11: 2-Aminoethylimidazole derivatives with therapeutic activity, part 3.
Scheme 12: 2-Aminoethylimidazole derivatives with therapeutic activity, part 4.
Scheme 13: 2-Aminoethylpyrazole derivatives with therapeutic activity.
Scheme 14: 2-Aminoethylisoxazole derivatives with therapeutic activity.
Scheme 15: 2-Aminoethylthiazole derivatives with therapeutic activity.
Scheme 16: 2-Aminoethyloxadiazole derivatives with therapeutic activity.
Scheme 17: 2-Aminoethyltriazole derivatives with therapeutic activity.
Scheme 18: 2-Aminoethyloxadiazole derivatives with therapeutic activity.
Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162
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...
Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152
Graphical Abstract
Figure 1: Steroidal spiro heterocycles with remarkable pharmacological activity.
Scheme 1: Synthesis of the spirooxetanone 2. a) t-BuOK, THF, rt, 16%.
Scheme 2: Synthesis of the 17-spirooxetane derivative 7. a) HC≡C(CH2)2CH2OTBDPS, n-BuLi, THF, BF3·Et2O, −78 °...
Scheme 3: Pd-catalyzed carbonylation of steroidal alkynols to produce α-methylene-β-lactones at C-3 and C-17 ...
Scheme 4: Catalyst-free protocol to obtain functionalized spiro-lactones by an intramolecular C–H insertion. ...
Scheme 5: One-pot procedure from dienamides to spiro-β-lactams. a) 1. Ac2O, DMAP, Et3N, CH2Cl2, 2. malononitr...
Scheme 6: Spiro-γ-lactone 20 afforded from 7α-alkanamidoestrone derivative 17. a) HC≡CCH2OTHP, n-BuLi, THF, –...
Scheme 7: Synthesis of the 17-spiro-γ-lactone 23, a key intermediate to obtain spironolactone. a) Ethyl propi...
Scheme 8: Synthetic pathway to obtain 17-spirodihydrofuran-3(2H)-ones from 17-oxosteroids. a) 1-Methoxypropa-...
Scheme 9: One-pot procedure to obtain 17-spiro-2H-furan-3-one compounds. a) NaH, diethyl oxalate, benzene, rt...
Scheme 10: Synthesis of 17-spiro-2H-furan-3-one derivatives. a) RCH=NOH, N-chlorosuccinimide/CHCl3, 99%; b) H2...
Scheme 11: Intramolecular condensation of a γ-acetoxy-β-ketoester to synthesize spirofuranone 37. a) (CH3CN)2P...
Scheme 12: Synthesis of spiro 2,5-dihydrofuran derivatives. a) Allyl bromide, DMF, NaH, 0 °C to rt, 93%; b) G-...
Scheme 13: First reported synthesis of C-16 dispiropyrrolidine derivatives. a) Sarcosine, isatin, MeOH, reflux...
Scheme 14: Cycloadducts 47 with antiproliferative activity against human cancer cell lines. a) 1,4-Dioxane–MeO...
Scheme 15: Spiropyrrolidine compounds generated from (E)-16-arylidene steroids and different ylides. a) Acenap...
Scheme 16: 3-Spiropyrrolidines 52a–c obtained from ketones 50a–c. a) p-Toluenesulfonyl hydrazide, MeOH, rt; b)...
Scheme 17: 16-Spiropyrazolines from 16-methylene-13α-estrone derivatives. a) AgOAc, toluene, rt, 78–81%.
Scheme 18: 6-Spiroimidazolines 57 synthesized by a one-pot multicomponent reaction. a) R3-NC, T3P®, DMSO, 70 °...
Scheme 19: Synthesis of spiro-1,3-oxazolines 60, tested as progesterone receptor antagonist agents. a) CF3COCF3...
Scheme 20: Synthesis of spiro-1,3-oxazolidin-2-ones 63 and 66a,b. a) RNH2, EtOH, 70 °C, 70–90%; b) (CCl3O)2CO,...
Scheme 21: Formation of spiro 1,3-oxazolidin-2-one and spiro 2-substituted amino-4,5-dihydro-1,3-oxazoles from ...
Scheme 22: Synthesis of diastereomeric spiroisoxazolines 74 and 75. a) Ar-C(Cl)=N-OH, DIPEA, toluene, rt, 74 (...
Scheme 23: Spiro 1,3-thiazolidine derivatives 77–79 obtained from 2α-bromo-5α-cholestan-3-one 76. a) 2-aminoet...
Scheme 24: Method for the preparation of derivative 83. a) Benzaldehyde, MeOH, reflux, 77%; b) thioglycolic ac...
Scheme 25: Synthesis of spiro 1,3-thiazolidin-4-one derivatives from steroidal ketones. a) Aniline, EtOH, refl...
Scheme 26: Synthesis of spiro N-aryl-1,3-thiazolidin-4-one derivatives 91 and 92. a) Sulfanilamide, DMF, reflu...
Scheme 27: 1,2,4-Trithiolane dimers 94a–e selectively obtained from carbonyl derivatives. a) LR, CH2Cl2, reflu...
Scheme 28: Spiro 1,2,4-triazolidin-3-ones synthesized from semicarbazones. a) H2O2, CHCl3, 0 °C, 82–85%.
Scheme 29: Steroidal spiro-1,3,4-oxadiazoline 99 obtained in two steps from cholest-5-en-3-one (97). a) NH2NHC...
Scheme 30: Synthesis of spiro-1,3,4-thiadiazoline 101 by cyclization and diacetylation of thiosemicarbazone 100...
Scheme 31: Mono- and bis(1,3,4-thiadiazolines) obtained from estrane and androstane derivatives. a) H2NCSNHNH2...
Scheme 32: Different reaction conditions to synthesize spiro-1,3,2-oxathiaphospholanes 108 and 109.
Scheme 33: Spiro-δ-lactones derived from ADT and epi-ADT as inhibitors of 17β-HSDs. a) CH≡C(CH2)2OTHP, n-BuLi,...
Scheme 34: Spiro-δ-lactams 123a,b obtained in a five-step reaction sequence. a) (R)-(+)-tert-butylsulfinamide,...
Scheme 35: Steroid-coumarin conjugates as fluorescent DHT analogues to study 17-oxidoreductases for androgen m...
Scheme 36: 17-Spiro estradiolmorpholinones 130 bearing two types of molecular diversity. a) ʟ- or ᴅ-amino acid...
Scheme 37: Steroidal spiromorpholinones as inhibitors of enzyme 17β-HSD3. a) Methyl ester of ʟ- or ᴅ-leucine, ...
Scheme 38: Steroidal spiro-morpholin-3-ones achieved by N-alkylation or N-acylation of amino diols 141, follow...
Scheme 39: Straightforward method to synthesize a spiromorpholinone derivative from estrone. a) BnBr, K2CO3, CH...
Scheme 40: Pyrazolo[4,3-e][1,2,4]-triazine derivatives 152–154. a) 4-Aminoantipyrine, EtOH/DMF, reflux, 82%; b...
Scheme 41: One-pot procedure to synthesize spiro-1,3,4-thiadiazine derivatives. a) NH2NHCSCONHR, H2SO4, dioxan...
Scheme 42: 1,2,4-Trioxanes with antimalarial activity. a) 1. O2, methylene blue, CH3CN, 500 W tungsten halogen...
Scheme 43: Tetraoxanes 167 and 168 synthesized from ketones 163, 165 and 166. a) NaOH, iPrOH/H2O, 80 °C, 93%; ...
Scheme 44: 1,2,4,5-Tetraoxanes bearing a steroidal moiety and a cycloalkane. a) 30% H2O2/CH2Cl2/CH3CN, HCl, rt...
Scheme 45: Spiro-1,3,2-dioxaphosphorinanes obtained from estrone derivatives. a) KBH4, MeOH, THF or CH2Cl2; b)...
Scheme 46: Synthesis of steroidal spiro-ε-lactone 183. a) 1. Jones reagent, acetone, 0 °C to rt, 2. ClCOCOCl, ...
Scheme 47: Synthesis of spiro-2,3,4,7-tetrahydrooxepines 185 and 187 derived from mestranol and lynestrenol (38...
Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146
Graphical Abstract
Figure 1: Oceanic distribution and marine holobiont sources of Microbulbifer strains described in the literat...
Figure 2: The chemical structure of agarose with the key β-1,4 linkage denoted.
Figure 3: The chemical structure of the biopolymer alginate.
Figure 4: The chemical structure of chitin.
Figure 5: Chemical structures of sulfated polysaccharides κ-, ι-, and λ-carrageenans.
Figure 6: Chemical structures of 4HBA (1) and parabens (2–14) isolated from Microbulbifer strains, and synthe...
Figure 7: Chemical structures of nucleosides 18–20 isolated from Microbulbifer strains.
Figure 8: Chemical structures of alkaloids 21–24 isolated from Microbulbifer strains.
Figure 9: Chemical structures of (2Z,4E)-3-methyl-2,4-decadienoic acid (25) and 4-BP (26) natural products is...
Figure 10: Chemical structures of bulbiferamides 27–30 and pseudobulbiferamides 31–35.
Figure 11: Proposed NRPS assembly lines for the biosynthesis of (A) bulbiferamide A (27) and (B) pseudobulbife...
Figure 12: Chemical structures of 2-heptyl-1H-quinolin-4-one (36, HHQ), 2-heptyl-1-hydroxyquinolin-4-one (37, ...
Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141
Graphical Abstract
Scheme 1: Representative protocols for the oxidative aromatic chlorination and bromination with iodine(III) r...
Scheme 2: Chlorination of 2-naphthol using the PIFA/AlCl3, 1:2 system.
Scheme 3: Bromination of 2-naphthol using the PIDA/AlBr3, 1:2 system.
Scheme 4: Reaction mechanism for the chlorination of 2-naphthol using the PIFA/AlCl3, 1:2 system.
Figure 1: Energy profile for the chlorination of 2-naphthol in the presence of PIFA and AlCl3.
Scheme 5: Calculated reaction mechanism for the bromination of 2-naphthol using the PIDA/AlBr3, 1:2 system.
Figure 2: Calculated mechanism for the bromination of 2-naphthol in the presence of PIDA and AlBr3.