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Search for "nucleophilic substitution" in Full Text gives 363 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Photoswitches beyond azobenzene: a beginner’s guide
- Michela Marcon,
- Christoph Haag and
- Burkhard König
Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143
- (37) followed by reduction with Zn/Ba(OH)2 and partial re-oxidation (Scheme 12A) [52]. They can also be obtained from o-halogenated benzyl bromides 40 by lithium–halogen exchange followed by nucleophilic substitution and a second lithium–halogen exchange with iodine (Scheme 12B) or by nickel-catalysed
- aldehyde and, if required, N-functionalisation via nucleophilic substitution (for aliphatic substituents) or palladium-catalysed cross-coupling (for aromatic substituents) (Scheme 25) [77]. Hemithioindigo can be synthesised by treating phenylthioacetic acid (83) with triflic acid. Then, the product is
Graphical Abstract
Figure 1: Energy diagram of a two-state photoswitch. Figure 1 was redrawn from [2].
Figure 2: Example of the absorption spectra of the isomers of a photoswitch with most efficient irradiation w...
Scheme 1: Photoswitch classes described in this review.
Figure 3: Azoheteroarenes.
Scheme 2: E–Z Isomerisation (top) and mechanisms of thermal Z–E isomerisation (bottom).
Scheme 3: Rotation mechanism favoured by the electron displacement in push–pull systems. Selected examples of...
Figure 4: A) T-shaped and twisted Z-isomers determine the thermal stability and the Z–E-PSS (selected example...
Figure 5: Effect of di-ortho-substitution on thermal half-life and PSS.
Figure 6: Selected thermal lifetimes of azoindoles in different solvents and concentrations. aConcentration o...
Figure 7: Aryliminopyrazoles: N-pyrazoles (top) and N-phenyl (bottom).
Scheme 4: Synthesis of symmetrical heteroarenes through oxidation (A), reduction (B), and the Bayer–Mills rea...
Scheme 5: Synthesis of diazonium salt (A); different strategies of azo-coupling: with a nucleophilic ring (B)...
Scheme 6: Synthesis of arylazothiazoles 25 (A) and heteroaryltriazoles 28 (B).
Scheme 7: Synthesis of heteroarylimines 31a,b [36-38].
Figure 8: Push–pull non-ionic azo dye developed by Velasco and co-workers [45].
Scheme 8: Azopyridine reported by Herges and co-workers [46].
Scheme 9: Photoinduced phase transitioning azobispyrazoles [47].
Figure 9: Diazocines.
Scheme 10: Isomers, conformers and enantiomers of diazocine.
Scheme 11: Partial overlap of the ππ* band with electron-donating substituents and effect on the PSS. Scheme 11 was ada...
Figure 10: Main properties of diazocines with different bridges. aMeasured in n-hexane [56]. bMeasured in THF. cMe...
Scheme 12: Synthesis of symmetric diazocines.
Scheme 13: Synthesis of asymmetric diazocines.
Scheme 14: Synthesis of O- and S-heterodiazocines.
Scheme 15: Synthesis of N-heterodiazocines.
Scheme 16: Puromycin diazocine photoswitch [60].
Figure 11: Indigoids.
Figure 12: The main representatives of the indigoid photoswitch class.
Scheme 17: Deactivation process that prevents Z-isomerisation of indigo.
Figure 13: Stable Z-indigo derivative synthesised by Wyman and Zenhäusern [67].
Figure 14: Selected examples of indigos with aliphatic and aromatic substituents [68]. Dashed box: proposed π–π in...
Scheme 18: Resonance structures of indigo and thioindigo involving the phenyl ring.
Scheme 19: Possible deactivation mechanism for 4,4'-dihydroxythioindigo [76].
Scheme 20: Effect of different heteroaryl rings on the stability and the photophysical properties of hemiindig...
Figure 15: Thermal half-lives of red-shifted hemithioindigos in toluene [79]. aMeasured in toluene-d8.
Scheme 21: Structures of pyrrole [81] and imidazole hemithioindigo [64].
Figure 16: Examples of fully substituted double bond hemithioindigo (left), oxidised hemithioindigos (centre),...
Scheme 22: Structure of iminothioindoxyl 72 (top) and acylated phenyliminoindolinone photoswitch 73 (bottom). ...
Scheme 23: (top) Transition states of iminothioindoxyl 72. The planar transition state is associated with a lo...
Scheme 24: Baeyer–Drewsen synthesis of indigo (top) and N-functionalisation strategies (bottom).
Scheme 25: Synthesis of hemiindigo.
Scheme 26: Synthesis of hemithioindigo and iminothioindoxyl.
Scheme 27: Synthesis of double-bond-substituted hemithioindigos.
Scheme 28: Synthesis of phenyliminoindolinone.
Scheme 29: Hemithioindigo molecular motor [85].
Figure 17: Arylhydrazones.
Scheme 30: Switching of arylhydrazones. Note: The definitions of stator and rotor are arbitrary.
Scheme 31: Photo- and acidochromism of pyridine-based phenylhydrazones.
Scheme 32: A) E–Z thermal inversion of a thermally stable push–pull hydrazone [109]. B) Rotation mechanism favoured...
Scheme 33: Effect of planarisation on the half-life.
Scheme 34: The longest thermally stable hydrazone switches reported so far (left). Modulation of thermal half-...
Figure 18: Dependency of t1/2 on concentration and hypothesised aggregation-induced isomerisation.
Figure 19: Structure–property relationship of acylhydrazones.
Scheme 35: Synthesis of arylhydrazones.
Scheme 36: Synthesis of acylhydrazones.
Scheme 37: Photoswitchable fluorophore by Aprahamian et al. [115].
Scheme 38: The four-state photoswitch synthesised by the Cigáň group [116].
Figure 20: Diarylethenes.
Scheme 39: Isomerisation and oxidation pathway of E-stilbene to phenanthrene.
Scheme 40: Strategies adapted to avoid E–Z isomerisation and oxidation.
Scheme 41: Molecular orbitals and mechanism of electrocyclisation for a 6π system.
Figure 21: Aromatic stabilisation energy correlated with the thermal stability of the diarylethenes [127,129].
Figure 22: Half-lives of diarylethenes with increasing electron-withdrawing groups [128,129].
Scheme 42: Photochemical degradation pathway promoted by electron-donating groups [130].
Figure 23: The diarylethenes studied by Hanazawa et al. [134]. Increased rigidity leads to bathochromic shift.
Scheme 43: The dithienylethene synthesised by Nakatani's group [135].
Scheme 44: Synthesis of perfluoroalkylated diarylethenes.
Scheme 45: Synthesis of 139 and 142 via McMurry coupling.
Scheme 46: Synthesis of symmetrical derivatives 145 via Suzuki–Miyaura coupling.
Scheme 47: Synthesis of acyclic 148, malonic anhydride 149, and maleimide derivatives 154.
Figure 24: Gramicidin S (top left) and two of the modified diarylethene derivatives: first generation (bottom ...
Scheme 48: Pyridoxal 5'-phosphate and its reaction with an amino acid (top). The analogous dithienylethene der...
Figure 25: Fulgides.
Scheme 49: The three isomers of fulgides.
Scheme 50: Thermal and photochemical side products of unsubstituted fulgide [150].
Figure 26: Maximum absorption λc of the closed isomer compared with the nature of the aromatic ring and the su...
Scheme 51: Possible rearrangement of the excited state of 5-dimethylaminoindolylfulgide [153].
Figure 27: Quantum yields of ring closure (ΦE→C) and E–Z isomerisation (ΦE→Z) correlated with the increasing s...
Scheme 52: Active (Eα) and inactive (Eβ) conformers (left) and the bicyclic sterically blocked fulgide 169 (ri...
Scheme 53: Quantum yield of ring-opening (ΦC→E) and E–Z isomerisation (ΦE→Z) for different substitution patter...
Scheme 54: Stobbe condensation pathway for the synthesis of fulgides 179, fulgimides 181 and fulgenates 178.
Scheme 55: Alternative synthesis of fulgides through Pd-catalysed carbonylation.
Scheme 56: Optimised synthesis of fulgimides [166].
Scheme 57: Photoswitchable FRET with a fulgimide photoswitch [167].
Scheme 58: Three-state fulgimide strategy by Slanina's group.
Figure 28: Spiropyrans.
Scheme 59: Photochemical (left) and thermal (right) ring-opening mechanisms for an exemplary spiropyran with a...
Figure 29: Eight possible isomers of the open merocyanine according to the E/Z configurations of the bonds hig...
Scheme 60: pH-Controlled photoisomerisation between the closed spiropyran 191-SP and the open E-merocyanine 19...
Scheme 61: Behaviour of spiropyran in water buffer according to Andréasson and co-workers [180]. 192-SP in an aqueo...
Scheme 62: (left box) Proposed mechanism of basic hydrolysis of MC [184]. (right box) Introduction of electron-dona...
Scheme 63: Photochemical interconversion of naphthopyran 194 (top) and spirooxazine 195 (bottom) photoswitches...
Scheme 64: Synthesis of spiropyrans and spirooxazines 198 and the dicondensation by-product 199.
Scheme 65: Alternative synthesis of spiropyrans and spirooxazines with indolenylium salt 200.
Scheme 66: Synthesis of 4’-substituted spiropyrans 203 by condensation of an acylated methylene indoline 201 w...
Scheme 67: Synthesis of spironaphthopyrans 210 by acid-catalysed condensation of naphthols and diarylpropargyl...
Scheme 68: Photoswitchable surface wettability [194].
Figure 30: Some guiding principles for the choice of the most suitable photoswitch. Note that this guide is ve...
3,3'-Linked BINOL macrocycles: optimized synthesis of crown ethers featuring one or two BINOL units
- Somayyeh Kheirjou,
- Jan Riebe,
- Maike Thiele,
- Christoph Wölper and
- Jochen Niemeyer
Beilstein J. Org. Chem. 2025, 21, 1719–1729, doi:10.3762/bjoc.21.134
- ]. For the synthesis of macrocycles M2 with two BINOL units, we relied on the monoiodide 12, which was first reacted in a two-fold Suzuki coupling to install the first linker, followed by silyl deprotection and introduction of the second linker via nucleophilic substitution [51]. Both procedures require
Graphical Abstract
Figure 1: a–d) Selected structures of previously reported BINOL-based crown ether macrocycles; e) previous sy...
Figure 2: Optimized synthetic routes towards 3,3'-substituted BINOL crown ethers (this work).
Figure 3: Synthetic routes towards macrocycles featuring one BINOL unit. a) Two-fold Suzuki coupling and b) t...
Figure 4: Molecular structure of macrocycle (R)-Me-M16 in the solid state (hydrogen atoms are omitted for cla...
Figure 5: Initially attempted route towards bis-BINOL macrocycles based on precursors Me-36 or Me-46. Conditi...
Figure 6: Synthetic route towards macrocycles featuring two BINOL units linked via hexaethylene glycol spacer...
Figure 7: Synthetic route towards macrocycles featuring two BINOL units linked via diethylene glycol spacers....
Figure 8: 1H NMR spectra of a) (S,S)-H-M22, b) (S,S)-iPr-M22, c) (S,S)-HiPr-M22, and d) (R,S)-HiPr-M22 (all: ...
Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides
- Nadezhda M. Metalnikova,
- Nikita S. Antonkin,
- Tuan K. Nguyen,
- Natalia S. Soldatova,
- Alexander V. Nyuchev,
- Mikhail A. Kinzhalov and
- Pavel S. Postnikov
Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110
- for unsymmetrical iodonium salts. Therefore, we moved to these to test the selectivity of aryl transfer under the established conditions. Since iodonium salts are prone to repeat the selectivity pattern of nucleophilic substitution in photoredox processes [35][36][37][38][39][40][41], we evaluated
Graphical Abstract
Scheme 1: Background and conception.
Scheme 2: Reaction scope of iodonium salts 1 and isonitriles. aReaction conditions: isonitrile (0.2 mmol), io...
Scheme 3: Selectivity experiments and scope of unsymmetrical iodoniums salts. aReaction conditions: 2-isocyan...
Scheme 4: Proposed reaction mechanism.
Wittig reaction of cyclobisbiphenylenecarbonyl
- Taito Moribe,
- Junichiro Hirano,
- Hideaki Takano,
- Hiroshi Shinokubo and
- Norihito Fukui
Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107
- nucleophilic substitution of the thus generated alkoxide to form an oxygen-containing five-membered ring. At least, density functional theory (DFT) calculations support that the nucleophilic attack of methylenetriphenylphosphorane to the exo-methylene unit is slightly favorable over reaction with the carbonyl
Graphical Abstract
Figure 1: Synthesis and structures of CBBC 1.
Scheme 1: Wittig reactions of CBBC 1.
Figure 2: X-ray crystal structures of (a) 3, (b) 4, and (c) 5 with thermal ellipsoids at 50% probability; all...
Figure 3: VT 1H NMR spectra of 5 in CD2Cl2 at (a) 298 K, (b) 243 K, and (c) 203 K. Blue circle and red triang...
Figure 4: Simulated dynamics of bis-olefin 5 at the B3LYP/6-31G(d) level of theory. The description for the c...
Figure 5: (a) UV–vis absorption (solid lines) and emission (dashed lines) spectra of 1 (black), 3 (blue), and ...
Scheme 2: Conversion of mono-olefin 3 to internally functionalized DBC derivative 6.
Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes
- Bartłomiej Pigulski
Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99
- bathochromically shifted compared to isomeric terrylenebisimide (λmax = 650 nm) [86] and even larger rylene bisimides like hexarylenebisimide (λmax = 953 nm) [87]. Bisimide 129 might be regioselectivily brominated using NBS, yielding PAH 130 in 80%. The bromide 130 undergoes nucleophilic substitution with
Graphical Abstract
Figure 1: a) Stone–Wales (red) and azulene (blue) defects in graphene; b) azulene and its selected resonance ...
Figure 2: Examples of azulene-embedded 2D allotropic forms of carbon: a) phagraphene and b) TPH-graphene.
Scheme 1: Synthesis of non-alternant isomers of pyrene (2 and 6) using dehydrogenation.
Scheme 2: Synthesis of non-alternant isomer 9 of benzo[a]pyrene and 14 of benzo[a]perylene using dehydrogenat...
Scheme 3: Synthesis of azulene-embedded isomers of benzo[a]pyrene (18 and 22) inspired by Ziegler–Hafner azul...
Figure 3: General strategies leading to azulene-embedded nanographenes: a) construction of azulene moiety in ...
Scheme 4: Synthesis of biradical PAHs possessing significant biradical character using oxidation of partially...
Scheme 5: Synthesis of dicyclohepta[ijkl,uvwx]rubicene (29) and its further modifications.
Scheme 6: Synthesis of warped PAHs with one embedded azulene subunit using Scholl-type oxidation.
Scheme 7: Synthesis of warped PAHs with two embedded azulene subunits using Scholl oxidation.
Scheme 8: Synthesis of azulene-embedded PAHs using [3 + 2] annulation accompanied by ring expansion.
Scheme 9: Synthesis of azulene-embedded isomers of linear acenes using [3 + 2] annulation accompanied by ring...
Scheme 10: Synthesis of azulene-embedded PAHs using intramolecular C–H arylation.
Scheme 11: Synthesis of azulene-embedded isomers of acenes using intramolecular C–H arylation.
Scheme 12: Synthesis of azulene-embedded PAHs using intramolecular condensations.
Scheme 13: Synthesis of azulene-embedded PAH 89 using palladium-catalysed [5 + 2] annulation.
Scheme 14: Synthesis of azulene-embedded PAHs using oxidation of substituents around the azulene core.
Scheme 15: Synthesis of azulene-embedded PAHs using the oxidation of reactive positions 1 and 3 of azulene sub...
Scheme 16: Synthesis of azulene-embedded PAHs using intramolecular C–H arylation.
Scheme 17: Synthesis of an azulene-embedded isomer of terylenebisimide using tandem Suzuki coupling and C–H ar...
Scheme 18: Synthesis of azulene embedded PAHs using a bismuth-catalyzed cyclization of alkenes.
Scheme 19: Synthesis of azulene-embedded nanographenes using intramolecular cyclization of alkynes.
Scheme 20: Synthesis of azulene-embedded graphene nanoribbons and azulene-embedded helicenes using annulation ...
Scheme 21: Synthesis of azulene-fused acenes.
Scheme 22: Synthesis of non-alternant isomer of perylene 172 using Yamamoto-type homocoupling.
Scheme 23: Synthesis of N- and BN-nanographenes with embedded azulene unit(s).
Scheme 24: On-surface synthesis of azulene-embedded nanographenes from benzenoid precursors via dehydrogenatio...
Scheme 25: On-surface synthesis of azulene-embedded nanographenes from benzenoid precursors.
Scheme 26: On-surface synthesis of azulene-embedded nanoribbons.
Synthetic approach to borrelidin fragments: focus on key intermediates
- Yudhi Dwi Kurniawan,
- Zetryana Puteri Tachrim,
- Teni Ernawati,
- Faris Hermawan,
- Ima Nurasiyah and
- Muhammad Alfin Sulmantara
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- iodide, and subsequent nucleophilic substitution with deprotonated (R,R)-91. The introduction of the OPMB functionality in compound 88 could then be achieved by following the steps employed in the transformation of 84 to 83. The synthesis via route A began with efforts to optimize the epimerization of
Graphical Abstract
Figure 1: Chemical structure of borrelidin (1).
Scheme 1: Synthetic strategy for Morken’s C2–C12 intermediate 20 as reported by Uguen et al. [41].
Scheme 2: Preparation of monoacetates 37 and ent-38 by Uguen et al. [41].
Scheme 3: Preparation of sulfones 27 and ent-27 by Uguen et al. [41].
Scheme 4: Attempts to couple sulfones 27 and ent-27 with epoxides 23a–c reported by Uguen et al. [41].
Scheme 5: Modified synthetic plan for Morken’s C2–C12 intermediate by Uguen [41].
Scheme 6: Revised synthetic strategy for Morken’s C2–C12 intermediate 20 by Uguen [41].
Scheme 7: Iterative synthesis of polydeoxypropionates developed by Zhou et al. [40].
Scheme 8: Application of iterative synthesis of polydeoxypropionate to construct the C3–C11 fragment 60 of bo...
Scheme 9: Retrosynthetic analysis of borrelidin by Yadav et al. [39].
Scheme 10: Two-carbon homologation of precursor 66 in the synthesize C1–C11 fragment 61 of borrelidin [39].
Scheme 11: Synthesis of the C1–C11 fragment 61 of borrelidin from monoalcohol 65 [39].
Scheme 12: Synthetic plan for Theodorakis’ C3–C11 fragment 82 of borrelidin by Laschat et al. [38].
Scheme 13: Synthesis of Theodorakis’ C3–C11 fragment 82 from compound 88 [38].
Scheme 14: Retrosynthesis of 61 and 62b by Minnaard and Madduri [37].
Scheme 15: Synthesis of intermediate 98 by Minnaard and Madduri [37].
Scheme 16: Synthesis of Ōmura’s C1–C11 fragment 61 by Minnaard and Madduri [37].
Scheme 17: Synthesis of fragment 62b of borrelidin as proposed by Minnaard and Madduri [37].
Scheme 18: Iterative directed allylation for the synthesis of deoxypropionates by Herber and Breit [33].
Scheme 19: Iterative copper-mediated directed allyl substitution for the synthesis of Theodorakis’ C3–C11 frag...
Scheme 20: Retrosynthesis of the C3–C17 fragment of borrelidin by Iqbal and co-workers [35].
Scheme 21: Synthesis of key intermediates 137 and 147 for the synthesis of the C3–C17 fragment of borrelidin.
Scheme 22: Synthesis of the C3–C17 fragment 150a,b of borrelidin.
Scheme 23: Synthesis of the C11–C15 fragment 155a of borrelidin.
Scheme 24: Macrocyclization of borrelidin model compounds 155a and 155b using ring-closing metathesis.
Recent advances in the electrochemical synthesis of organophosphorus compounds
- Babak Kaboudin,
- Milad Behroozi,
- Sepideh Sadighi and
- Fatemeh Asgharzadeh
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- )(OR)2. The final product was formed by a simple nucleophilic substitution of the phosphorus center (Scheme 20). The N–P bond formation is a critical process in organic synthesis due to the preparation of various materials with different biological and medicinal activities. In 2021 Wang et al. [65
- reaction proceeded with anodic oxidation of iodide to iodine, followed by a reaction with dialkyl phosphite to give I–P(O)(OR)2. The final product was formed by a simple nucleophilic substitution of phenols with I–P(O)(OR)2. In 2021, Wang et al. [65] presented a report on electrochemical P–O bond formation
- the rings contained electron-withdrawing groups. It is suggested that the reaction proceeded via single-electron oxidation of thiocyanate at the anode. DBU was used in the reaction for a simple nucleophilic substitution of phosphonate with a cyanide group in the formed intermediate (Scheme 28). In
Graphical Abstract
Scheme 1: Electrosynthesis of phenanthridine phosphine oxides.
Scheme 2: Electrosynthesis of 1-aminoalkylphosphine oxides.
Scheme 3: Various electrochemical C–P coupling reactions.
Scheme 4: Electrochemical C–P coupling reaction of indolines.
Scheme 5: Electrochemical C–P coupling reaction of ferrocene.
Scheme 6: Electrochemical C–P coupling reaction of acridines with phosphites.
Scheme 7: Electrochemical C–P coupling reaction of alkenes.
Scheme 8: Electrochemical C–P coupling reaction of arenes in a flow system.
Scheme 9: Electrochemical C–P coupling reaction of heteroarenes.
Scheme 10: Electrochemical C–P coupling reaction of thiazoles.
Scheme 11: Electrochemical C–P coupling reaction of indole derivatives.
Scheme 12: Electrosynthesis of 1-amino phosphonates.
Scheme 13: Electrochemical C–P coupling reaction of aryl and vinyl bromides.
Scheme 14: Electrochemical C–P coupling reaction of phenylpyridine with dialkyl phosphonates in the presence o...
Scheme 15: Electrochemical P–C bond formation of amides.
Scheme 16: Electrochemical synthesis of α-hydroxy phosphine oxides.
Scheme 17: Electrochemical synthesis of π-conjugated phosphonium salts.
Scheme 18: Electrochemical phosphorylation of indoles.
Scheme 19: Electrochemical synthesis of phosphorylated propargyl alcohols.
Scheme 20: Electrochemical synthesis of phosphoramidates.
Scheme 21: Electrochemical reaction of carbazole with diphenylphosphine.
Scheme 22: Electrochemical P–N coupling of carbazole with phosphine oxides.
Scheme 23: Electrochemical P–N coupling of indoles with a trialkyl phosphite.
Scheme 24: Electrochemical synthesis of iminophosphoranes.
Scheme 25: Electrochemical P–O coupling of phenols with dialkyl phosphonate.
Scheme 26: Electrochemical P–O coupling of alcohols with diphenylphosphine.
Scheme 27: Electrochemical P–S coupling of thiols with dialkylphosphines.
Scheme 28: Electrochemical thiophosphorylation of indolizines.
Scheme 29: Electrosynthesis of S-heteroaryl phosphorothioates.
Scheme 30: Electrochemical phosphorylation reactions.
Scheme 31: Electrochemical P–Se formation.
Scheme 32: Electrochemical selenation/halogenation of alkynyl phosphonates.
Scheme 33: Electrochemical enantioselective aryl C–H bond activation.
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
- Leon M. Friedrich and
- Thisbe K. Lindhorst
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- azobenzene derivative 9 [34] to furnish 10. This reaction had to be carried out at −78 °C in order to suppress nucleophilic substitution of the ortho-fluorine substituents in 9 by the thiol 8, a reaction that competes with the desired cross-coupling. For the second Buchwald–Hartwig–Migita cross-coupling, the
Graphical Abstract
Figure 1: Cartoon of the photoswitchable glycoconjugates investigated in this account. The previously describ...
Scheme 1: Synthesis of the homobivalent azobenzene glycocluster 6αMan3αMan 2. Reagents and conditions: a) BF3...
Scheme 2: Synthesis of the antennas 6βGlc 3 and 3αMan 4 (A), and 6αMan 5 (B). Reagents and conditions: a) DTT...
Figure 2: A: Wavelength-selective photoswitching of the α-ᴅ-mannopyranosyloxy-AB and -ABF4 antennas comprised...
Figure 3: Comparison of the inhibitory potencies of 1, 2, 4, and 5 in the different isomeric states. The depi...
Figure 4: Three-dimensional representation of the superimposed most stable ligand–protein complexes from IFD ...
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
- last step (nucleophilic substitution in intermediate C by the amine compound). Depending on the conditions, the role of the base can be fulfilled by the amine itself [63] or by the addition of another base such as DBU [66], DABCO [64], or TMG [65]. This mechanism is supported by experimental evidence
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.
Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages
- Keith G. Andrews
Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30
- generated large electrostatic effects by functionalizing the capsule exteriors with charged groups (Figure 4D) [136][137]. Observed rate accelerations for capsule-promoted nucleophilic substitution reactions demonstrate significant enthalpic stabilization of the transition state attributable due to the
- nucleophile and electrophile in a glycosylation reaction [105]. (D) An externally charged cavitand promotes charge-stabilized nucleophilic substitution reactions of hydrophobically encapsulated substrates [136][137]. (A) Metal-organic cages and key modes in catalysis. (B) Charged metals or ligands can result
Graphical Abstract
Figure 1: Catalytic rate enhancements from a reduction in the Gibbs free energy transition barrier can be fra...
Figure 2: Typical catalysis modes using macrocycle cavities performing (non-specific) hydrophobic substrate b...
Figure 3: (A) Cram’s serine protease model system [87,88]. The macrocycle showed strong substrate binding (organizat...
Figure 4: (A) Self-assembling capsules can perform hydrophobic catalysis [116,117]. (B) Resorcin[4]arene building bloc...
Figure 5: (A) Metal-organic cages and key modes in catalysis. (B) Charged metals or ligands can result in +/−...
Figure 6: (A) Frameworks (MOFs, COFs) can be catalysts. (B) Example of a 2D-COF, assembled by dynamic covalen...
Figure 7: (A) Examples of dynamic covalent chemistry used to synthesize organic cages. (B) Organic cages are ...
Figure 8: (A) Design and development of soluble, functionalized, robust organic cages. (B) Examples of modula...
Figure 9: (A) There are 13 metastable conformers (symmetry-corrected) for cage 1 due to permutations of amide...
The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation
- Rituparna Das and
- Balaram Mukhopadhyay
Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27
- glycosylation. Conventional glycosylation involves the ‘nucleophilic substitution’ of the leaving group at the sp3 anomeric centre of the donor moiety with a suitable carbohydrate or non-carbohydrate-based aglycon with the help of an electrophilic promoter to form the equatorial glycoside 7 or the axial
Graphical Abstract
Scheme 1: Continuum in the mechanistic pathway of glycosylation [32] reactions ranging between SN2 and SN1.
Scheme 2: Formation of 1,2-trans glycosides by neighbouring group participation with acyl protection in C-2 p...
Scheme 3: Solvent-free activation [92] of disarmed per-acetylated (15) and per-benzoylated (18) glycosyl donors.
Scheme 4: Synthesis of donor 2-(2,2,2-trichloroethoxy)glucopyrano-[2,1-d]-2-oxazoline 22 [94] and regioselective ...
Scheme 5: The use of levulinoyl protection for an orthogonal glycosylation reaction.
Figure 1: The derivatives 32–36 of the pivaloyl group.
Scheme 6: Benzyl and cyanopivalolyl ester-protected hexarhamnoside derivative 37 and its global deprotection ...
Scheme 7: Orthogonal chloroacetyl group deprotection in oligosaccharide synthesis [113].
Figure 2: The derivatives of the chloroacetyl group: CAMB protection (41) [123], CAEB protection (42) [124], POMB prote...
Scheme 8: Use of the (2-nitrophenyl)acetyl protecting group [126] as the neighbouring group protecting group at th...
Scheme 9: Neighbouring group participation protocol by the BnPAc protecting group [128] in the C-2 position.
Scheme 10: Glycosylation reaction with O-PhCar (54) and O-Poc (55) donors showing high β-selectivity [133].
Scheme 11: Neighbouring group participation rendered by an N-benzylcarbamoyl (BnCar) group [137] at the C-2 positio...
Scheme 12: Stereoselectivity obtained from glycosylation [138] with 2-O-(o-trifluoromethylbenzenesulfonyl)-protecte...
Scheme 13: (a) Plausible mechanistic pathway for glycosylation with C-2 DMTM protection [139] and (b) example of a ...
Scheme 14: Glycosylation reactions employing MOM 78, BOM 81, and NAPOM 83-protected thioglycoside donors. Reag...
Scheme 15: Plausible mechanistic pathway for alkoxymethyl-protected glycosyl donors. Path A. Expected product ...
Scheme 16: Plausible mechanistic pathway for alkoxymethyl-protected glycosyl donors [147].
Scheme 17: A. Formation of α-glycosides and B formation of β-glycosides by using chiral auxiliary neighbouring...
Scheme 18: Bimodal participation of 2-O-(o-tosylamido)benzyl (TAB) protecting group to form both α and β-isome...
Scheme 19: (a) 1,2-trans-Directing nature using C-2 cyanomethyl protection and (b) the effect of acceptors and...
Scheme 20: 1,3-Remote assistance by C-3-ester protection for gluco- and galactopyranosides to form 1,2-cis gly...
Scheme 21: 1,6-Remote assistance by C-6-ester protection for gluco- and galactopyranosides to form 1,2-cis gly...
Scheme 22: 1,4-Remote assistance by C-4-ester protection for galactopyranosides to form 1,2-cis glycosidic pro...
Scheme 23: Different products obtained on activation of axial 3-O and equatorial 3-O ester protected glycoside...
Scheme 24: The role of 3-O-protection on the stereochemistry of the produced glycoside [191].
Scheme 25: The role of 4-O-protection on the stereochemistry of the produced glycosides.
Scheme 26: Formation and subsequent stability of the bicyclic oxocarbenium intermediate formed due to remote p...
Scheme 27: The role a C-6 p-nitrobenzoyl group on the stereochemistry of the glycosylated product [196].
Scheme 28: Difference in stereoselectivity obtained in glycosylation reactions by replacing non-participating ...
Scheme 29: The role of electron-withdrawing and electron-donating substituents on the C-4 acetyl group in glyc...
Scheme 30: Effect of the introduction of a methyl group in the C-4 position on the glycosylation with more rea...
Figure 3: Remote group participation effect exhibited by the 2,2-dimethyl-2-(o-nitrophenyl)acetyl (DMNPA) pro...
Scheme 31: The different stereoselectivities obtained by Pic and Pico donors on being activated by DMTST.
Figure 4: Hydrogen bond-mediated aglycon delivery (HAD) in glycosylation reactions for 1,2-cis 198a and 1,2-t...
Scheme 32: The role of different acceptor with 6-O-Pic-protected glycosyl donors.
Scheme 33: The role of the remote C-3 protection on various 4,6-O-benzylidene-protected mannosyl donors affect...
Scheme 34: The dual contribution of the DTBS group in glycosylation reactions [246,247].
Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles
- Zi-Ying Xiao,
- Jing Sun and
- Chao-Guo Yan
Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21
- Zi-Ying Xiao Jing Sun Chao-Guo Yan College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China 10.3762/bjoc.21.21 Abstract In this paper, the nucleophilic substitution reactions of various N- and P-containing nucleophiles to MBH carbonates of isatins were investigated
- synthetic methodologies and in continuation of our aim to develop domino reactions based on MBH carbonates of isatins for efficient construction of diverse polycyclic spiroindolinones [42][43][44][45][46][47][48][49][50][51][52], herein, we wish to report the nucleophilic substitution reactions of various N
- investigated nucleophilic substitution reactions of various N- and P-containing nucleophiles to MBH carbonates of isatins. It is interesting to find that diverse functionalized 3-substituted oxindole derivatives were successfully prepared in satisfactory yields and with high diastereoselectivity. In addition
Graphical Abstract
Scheme 1: Reaction of arylamines and MBH carbonates of isatins. Reaction conditions: MBH carbonate of isatin ...
Scheme 2: Reaction of arylamines and MBH maleimides of isatins. Reaction conditions: MBH maleimide of isatin ...
Figure 1: Single crystal structure of compound 5a.
Figure 2: Single crystal structure of compound 5j.
Scheme 3: Reactions of MBH carbonates of isatins and triphenylphosphine. Reaction conditions: MBH carbonate o...
Figure 3: Single crystal structure of compound 6e.
Figure 4: Single crystal structure of compound 7a.
Figure 5: Single crystal structure of compound 8a.
Scheme 4: Proposed reaction mechanism for the various compounds.
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
- -catalyzed reaction of indoles 210 with 2-nitrosonaphthalenes 211 was conducted in 2020 (Scheme 63) [93]. In combination with catalyst hydrogen bonding, the nitroso group was identified as a suitable partner for the nucleophilic substitution by possessing a sufficiently low LUMO energy value. Based on the
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.
Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives
- Shuxian Qiu,
- Duan Dong,
- Jiahui Li,
- Huiting Wen,
- Jinpeng Li,
- Yu Yang,
- Shengxian Zhai and
- Xingyuan Gao
Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274
- available 2-bromo-4-fluoro-1-nitrobenzene, featuring a noble-metal-free system, mild reaction conditions, and a good yield, especially for the final Cs2CO3-facilitated nucleophilic substitution (77–91% yield). The characterization data obtained from IR and NMR spectroscopy (1H, 13C, 19F, and 31P) as well as
- hand, we turned our attention to the synthesis of PhFlOP-based compounds through a Cs2CO3-facilitated nucleophilic substitution with substituted carbazoles as the nucleophiles (Scheme 2). For example, tert-butyl, bromo, carbazolyl, or phenyl substituents were introduced into the carbazoles. To our
Graphical Abstract
Scheme 1: Preparation of key intermediate 5.
Scheme 2: Synthesis of PhFlOP-based molecules 7.
Figure 1: An ORTEP drawing obtained using the X-ray crystallographic data of 7-H.
Figure 2: (a) UV–vis absorption spectra of the PhFlOP-based emitters 7 measured at a concentration of ≈10−5 M...
Figure 3: (a) PL spectra of the PhFlOP-based emitters 7 measured in toluene at room temperature. (b) PL spect...
Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases
- Yang Chen,
- Jiao He,
- Hang Lin,
- Hai-Feng Wang,
- Ping Hu,
- Bi-Qin Wang,
- Ke-Qing Zhao and
- Bertrand Donnio
Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270
- chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SNFAr) of various types of commercially available fluoroarenes with the electrophilic
- subsequent second annulation, yielding a new series of extended polyaromatic mesomorphic compounds, i.e., 1,1',3,3',4,4'-hexafluoro-6,6',7,7',10,10',11,11'-octaalkoxy-2,2'-bitriphenylene (Gnm) which were found to display a Colrec mesophase. The specific nucleophilic substitution patterns of the Fn
- red-shift of the emission peak. Keywords: arene–perfluoroarene interaction; decafluorobiphenyl; fluorinated triphenylene; fluoroarene nucleophilic substitution; organolithium; Introduction Non-covalent arene–fluoroarene intermolecular interactions [1][2] are drawing increasing attention due to their
Graphical Abstract
Figure 1: Fluorotriphenylene derivatives and their nonfluorinated homologs obtained by SNFAr from 2,2'-dilith...
Scheme 1: Synthesis, yields, and nomenclature of 1,2,4-trifluoro-6,7,10,11-tetraalkoxy-3-(perfluorophenyl)tri...
Figure 2: Single crystal structure of 1,2,4-trifluoro-3-(perfluorophenyl)triphenylene (F) viewed along the ma...
Figure 3: POM textures, observed between crossed polarizers of Janus and dimer, F6, F12, G66, and G48, respec...
Figure 4: Comparative bar graph summarizing the thermal behavior of Fn, BTP6, and PHn derivatives (2nd heatin...
Figure 5: Representative S/WAXS patterns of Fn and Gnm compounds.
Figure 6: Absorption (a) and emission (b) spectra of F6 and G66, measured in different solvents at a concentr...
Figure 7: DFT calculated frontier molecular orbitals and optimized molecular structures for F1 and G11.
Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines
- Sergio Torres-Oya and
- Mercedes Zurro
Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268
- -derived azadiene by H-bonding. This dual activation promotes a stereoselective addition of 3-chlorooxindole to the azadiene leading to intermediate A. The latter is also activated by the chiral guanidine and undergoes an intramolecular nucleophilic substitution which delivers the product 19b with the
Graphical Abstract
Figure 1: Reactivity of α,β-unsaturated imines and variety of structures.
Figure 2: The hetero-Diels–Alder and inverse electron demand hetero-Diels–Alder reactions.
Figure 3: Different strategies to promote the activation of dienes and dienophiles in IEDADA reactions.
Figure 4: Examples of non-covalent interactions in organocatalysis.
Scheme 1: Enantioselective bifunctional thiourea-catalyzed inverse electron demand Diels–Alder reaction of N-...
Scheme 2: Cinchona-derived thiourea-catalyzed stereoselective (3 + 2) reaction of α,β-unsaturated imines and ...
Scheme 3: Cinchona-derived thiourea-catalyzed stereoselective (3 + 2)/(4 + 2) cascade reaction of α,β-unsatur...
Scheme 4: Enantioselective bifunctional squaramide-catalyzed formal [4 + 2] cycloaddition of malononitrile wi...
Scheme 5: Bifunctional squaramide-catalyzed IEDADA reaction of saccharin-derived 1-azadienes and azlactones.
Scheme 6: Chiral guanidine-catalyzed enantioselective (4+1) cyclization of benzofuran-derived azadienes with ...
Scheme 7: Bifunctional squaramide-catalyzed [4 + 2] cyclization of benzofuran-derived azadienes and azlactone...
Scheme 8: Chiral bifunctional squaramide-catalyzed domino Mannich/formal [4 + 2] cyclization of 2-benzothiazo...
Scheme 9: Chiral bifunctional thiourea-catalyzed formal IEDADA reaction of β,γ-unsaturated ketones and benzof...
Scheme 10: Dihydroquinine-derived squaramide-catalyzed (3 + 2) cycloaddition reaction of isocyanoacetates and ...
Scheme 11: Enantioselective squaramide-catalyzed asymmetric IEDADA reaction of benzofuran-derived azadienes an...
Scheme 12: Scale up and derivatizations of benzofuran-fused 2-piperidinol derivatives.
Scheme 13: Dihydroquinine-derived squaramide-catalyzed Mannich-type reaction of isocyanoacetates with N-(2-ben...
Figure 5: Structure of a cinchona alkaloid and (DHQD)2PHAL.
Scheme 14: Enantioselective modified cinchona alkaloid-catalyzed [4 + 2] annulation of γ-butenolides and sacch...
Scheme 15: Chiral tertiary amine-catalyzed [2 + 4] annulation of cyclic 1-azadiene with γ-nitro ketones.
Scheme 16: Inverse electron demand aza-Diels–Alder reaction (IEDADA) of 1-azadienes with enecarbamates catalyz...
Scheme 17: Phosphoric acid-catalyzed enantioselective [4 + 2] cycloaddition of benzothiazolimines and enecarba...
Scheme 18: Phosphoric acid-catalyzed enantioselective inverse electron demand aza-Diels–Alder reaction of in s...
Scheme 19: Proposed reaction mechanism for the phosphoric acid-catalyzed enantioselective inverse electron dem...
Scheme 20: Enantioselective dearomatization of indoles by a (3 + 2) cyclization with azoalkenes catalyzed by a...
Scheme 21: Synthetic applicability of the pyrroloindoline derivatives.
Scheme 22: Chiral phosphoric acid-catalyzed (2 + 3) dearomative cycloaddition of 3-alkyl-2-vinylindoles with a...
Scheme 23: Chiral phosphoric acid-catalyzed asymmetric [4 + 2] cycloaddition of aurone-derived 1-azadienes and...
Scheme 24: Phosphoric acid-catalyzed enantioselective formal [4 + 2] cycloaddition of dienecarbamates and 2-be...
Scheme 25: Chiral phosphoric acid-catalyzed asymmetric inverse electron demand aza-Diels–Alder reaction of 1,3...
Scheme 26: Chiral phosphoric acid-catalyzed asymmetric Attanasi reaction between 1,3-dicarbonyl compounds and ...
Scheme 27: Synthetic applicability of the NPNOL derivatives.
Scheme 28: Chiral phosphoric acid-catalyzed asymmetric intermolecular formal (3 + 2) cycloaddition of azoalken...
Scheme 29: Enantioselective [4 + 2] cyclization of α,β-unsaturated imines and azlactones.
Scheme 30: Catalytic cycle for the chiral phosphoric acid-catalyzed enantioselective [4 + 2] cyclization of α,...
Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures
- Yosuke Akae
Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252
- structure in the early days. Rotaxane bearing a dumbbell comprising only covalent bonds was first reported by Harada and co-workers in 1997 (Scheme 1B) [38]. In this system, the end-capping reaction was based on the nucleophilic substitution of the amino groups on the axle ends. Afterward, such nucleophilic
- synthesis, Harada and co-workers reported the end-capping reaction based on nucleophilic substitution by the amino groups on axle ends (Scheme 2) [43]. Similarly, other highly efficient reactions have been performed as end-capping reactions to produce polyrotaxane [13][14][15]. In addition to the simple
- substitution/addition reactions became the standard for end-capping reactions, although a transition metal–catalyzed cross-coupling reaction has also been used to synthesize CD-based rotaxane. Typically, water-soluble components are prepared, after which the Suzuki coupling reaction in water is used to
Graphical Abstract
Figure 1: Overview of the CD-based rotaxane as a polymer material covered in this review.
Figure 2: CD structure.
Figure 3: Typical pathway for synthesizing CD-based rotaxanes.
Scheme 1: (A) Synthesis of α-CD-based [2]rotaxane via a metal–ligand complex. (B) Chemical structures of meth...
Scheme 2: Synthesis of α-CD-based polyrotaxane.
Scheme 3: Facile [3]rotaxane synthesis by the urea end-capping method.
Figure 4: (A) Single-crystal structure of α-CD-based [3]rotaxane 3 and PMα-CD-based [3]rotaxane 4. (B) Schema...
Figure 5: Structural control of CD-based [2]rotaxane via (A) light irradiation and (B) light irradiation and ...
Figure 6: Relationship among the plus–minus signs of ICD, the position of the guest molecule, and the axis of...
Figure 7: Structural control of CD-based rotaxane via (A) redox reaction and (B) in a solvent.
Scheme 4: (A) Synthesis of pseudopolyrotaxane bearing an ABA triblock copolymer as an axle. (B) Two synthetic...
Scheme 5: Slippage of size-complementary rotaxanes.
Figure 8: (A) Reversible formation of the CD-based [2]rotaxane. (B) Deslipping reaction of the CD-based size-...
Figure 9: (A) Chemical structures of [3]rotaxanes 2 and 3. (B) Schematic of the deslipping reaction of [3]rot...
Figure 10: (A) Modification of the axle ends of [3]rotaxane by (1) bromination and (2) the Suzuki coupling rea...
Figure 11: (A) ICD spectra of [3]rotaxanes bearing acylated (top) and conventional (bottom) CDs. (B) Schematic...
Figure 12: Synthesis of macromolecular[3]rotaxane via a size-complementary protocol.
Figure 13: Conjugated polymer insulated by (A) β-CD. (B) Triphenylamine-substituted β-CD.
Figure 14: Synthesis of the VSC and successive rotaxane-crosslinked polymer (RCP) preparation.
Figure 15: (A) Chemical structure of the [3]rotaxane crosslinker (RC). (B) Schematic of the synthesis and de-c...
Figure 16: (A) Random vinylation of the CD-based [3]rotaxane; (B) Schematic of the reaction between α-CD and m...
Figure 17: (A) Aggregation of CD-based [3]rotaxane. (B) Schematic of the plausible mechanism of the aggregatio...
Advances in radical peroxidation with hydroperoxides
- Oleg V. Bityukov,
- Pavel Yu. Serdyuchenko,
- Andrey S. Kirillov,
- Gennady I. Nikishin,
- Vera A. Vil’ and
- Alexander O. Terent’ev
Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249
- mainly include: nucleophilic addition or nucleophilic substitution with H2O2 or ROOH [17][18], autoxidation with O2, pericyclic reactions of unsaturated bonds with O3 or O2, and metal-catalyzed peroxidation (Isayama–Mukaiyama hydrosilylperoxidation [19][20], for example) [21][22][23]. As the topic is
- styrenes 217, oxygen sources (water or alcohol), and TBHP mediated by ammonium iodine has been developed (Scheme 68) [137]. Addition of the tert-butylperoxy radical to alkene 217 followed by SN2 nucleophilic substitution with O-source was considered as a possible pathway to the formation of products 218
Graphical Abstract
Scheme 1: Organic peroxide initiators in polymer chemistry.
Scheme 2: Synthesis of organic peroxides.
Scheme 3: Richness of radical cascades with species formed from hydroperoxides in redox conditions.
Scheme 4: Co-catalyzed allylic peroxidation of alkenes 1 and 3 by TBHP.
Scheme 5: Allylic peroxidation of alkenes 6 by Pd(II)TBHP.
Scheme 6: Cu(I)-catalyzed allylic peroxidation.
Scheme 7: Enantioselective peroxidation of alkenes 10 with TBHP in the presence of copper(I) compounds.
Scheme 8: Oxidation of α-pinene (12) by the Cu(I)/TBHP system.
Scheme 9: Introduction of the tert-butylperoxy fragment into the α-position of cyclic ketones 15 and 17.
Scheme 10: α-Peroxidation of β-dicarbonyl compounds 19 using the Cu(II)/TBHP system.
Scheme 11: Co-catalyzed peroxidation of cyclic compounds 21 with TBHP.
Scheme 12: Co-, Mn- and Fe-catalyzed peroxidation of 2-oxoindoles 23, barbituric acids 25, and 4-hydroxycoumar...
Scheme 13: Cu-catalyzed and metal-free peroxidation of barbituric acid derivatives 31 and 3,4-dihydro-1,4-benz...
Scheme 14: Electrochemical peroxidation of 1,3-dicarbonyl compounds 35.
Scheme 15: Peroxidation of β-dicarbonyl compounds, cyanoacetic esters and malonic esters 37 by the TBAI/TBHP s...
Scheme 16: Cu-catalyzed peroxidation of malonodinitriles and cyanoacetic esters 39 with TBHP.
Scheme 17: Mn-catalyzed remote peroxidation via trifluromethylation of double bond.
Scheme 18: Cu-catalyzed remote peroxidation via trifluromethylthiolation of double bond.
Scheme 19: Fe-, Mn-, and Ru-catalyzed peroxidation of alkylaromatics 45, 47, 49, and 51 with TBHP.
Scheme 20: Cu-catalyzed peroxidation of diphenylacetonitrile (53) with TBHP.
Scheme 21: Cu-catalyzed peroxidation of benzyl cyanides 60 with TBHP.
Scheme 22: Synthesis of tert-butylperoxy esters 63 from benzyl alcohols 62 using the TBAI/TBHP system.
Scheme 23: Enantioselective peroxidation of 2-phenylbutane (64) with TBHP and chiral Cu(I) complex.
Scheme 24: Photochemical synthesis of peroxides 67 from carboxylic acids 66.
Scheme 25: Photochemical peroxidation of benzylic C(sp3)–H.
Scheme 26: Cu- and Ru-catalyzed peroxidation of alkylamines with TBHP.
Scheme 27: Peroxidation of amides 76 with the TBAI/TBHP system.
Scheme 28: Fe-catalyzed functionalization of ethers 78 with TBHP.
Scheme 29: Synthesis of 4-(tert-butylperoxy)-5-phenyloxazol-2(3H)-ones 82 from benzyl alcohols 80 and isocyana...
Scheme 30: Fe- and Co-catalyzed peroxidation of alkanes with TBHP.
Scheme 31: Rh-catalyzed tert-butylperoxy dienone synthesis with TBHP.
Scheme 32: Rh- and Cu-catalyzed phenolic oxidation with TBHP.
Scheme 33: Metal-free peroxidation of phenols 94.
Scheme 34: Cu-catalyzed alkylation–peroxidation of acrylonitrile.
Scheme 35: Cu-catalyzed cycloalkylation–peroxidation of coumarins 99.
Scheme 36: Metal-free cycloalkylation–peroxidation of coumarins 102.
Scheme 37: Difunctionalization of indene 104 with tert-butylperoxy and alkyl groups.
Scheme 38: Acid-catalyzed radical addition of ketones (108, 111) and TBHP to alkenes 107 and acrylates 110.
Scheme 39: Cu-catalyzed alkylation–peroxidation of alkenes 113 with TBHP and diazo compounds 114.
Scheme 40: Cobalt(II)-catalyzed addition of TBHP and 1,3-dicarbonyl compound 116 to alkenes 117.
Scheme 41: Cu(0)- or Co(II)-catalyzed addition of TBHP and alcohols 120 to alkenes 119.
Scheme 42: Fe-catalyzed functionalization of allenes 122 with TBHP.
Scheme 43: Fe-catalyzed alkylation–peroxidation of alkenes 125 and 127.
Scheme 44: Fe- and Co-catalyzed alkylation–peroxidation of alkenes 130, 133 and 134 with TBHP and aldehydes as...
Scheme 45: Carbonylation–peroxidation of alkenes 137, 140, 143 with hydroperoxides and aldehydes.
Scheme 46: Carbamoylation–peroxidation of alkenes 146 with formamides and TBHP.
Scheme 47: TBAB-catalyzed carbonylation–peroxidation of alkenes.
Scheme 48: VOCl2-catalyzed carbonylation–peroxidation of alkenes 152.
Scheme 49: Acylation–peroxidation of alkenes 155 with aldehydes 156 and TBHP using photocatalysis.
Scheme 50: Cu-catalyzed peroxidation of styrenes 158.
Scheme 51: Fe-catalyzed acylation-peroxidation of alkenes 161 with carbazates 160 and TBHP.
Scheme 52: Difunctionalization of alkenes 163, 166 with TBHP and (per)fluoroalkyl halides.
Scheme 53: Difunctionalization of alkenes 169 and 172 with hydroperoxides and sodium (per)fluoromethyl sulfina...
Scheme 54: Trifluoromethylation–peroxidation of styrenes 175 using MOF Cu3(BTC)2 as a catalyst.
Scheme 55: Difunctionalization of alkenes 178 with tert-butylperoxy and dihalomethyl fragments.
Scheme 56: Difunctionalization of alkenes 180 with the tert-butylperoxy and dihalomethyl moieties.
Scheme 57: The nitration–peroxidation of alkenes 182 with t-BuONO and TBHP.
Scheme 58: Azidation–peroxidation of alkenes 184 with TMSN3 and TBHP.
Scheme 59: Co-catalyzed bisperoxidation of butadiene 186.
Scheme 60: Bisperoxidation of styrene (189) and acrylonitrile (192) with TBHP by Minisci.
Scheme 61: Mn-catalyzed synthesis of bis(tert-butyl)peroxides 195 from styrenes 194.
Scheme 62: Bisperoxidation of arylidene-9H-fluorenes 196 and 3-arylidene-2-oxoindoles 198 with TBHP under Mn-c...
Scheme 63: Synthesis of bisperoxides from styrenes 200 and 203 using the Ru and Rh catalysis.
Scheme 64: Iodine-catalyzed bisperoxidation of styrenes 206.
Scheme 65: Synthesis of di-tert-butylperoxyoxoindoles 210 from acrylic acid anilides 209 using a Pd(II)/TBHP o...
Scheme 66: Pinolation/peroxidation of styrenes 211 catalyzed by Cu(I).
Scheme 67: TBAI-catalyzed acyloxylation–peroxidation of alkenes 214 with carboxylic acids and TBHP.
Scheme 68: Difunctionalization of alkenes 217 with TBHP and water or alcohols.
Scheme 69: TBAI-catalyzed hydroxyperoxidation of 1,3-dienes 220.
Scheme 70: Hydroxyperoxidation of 1,3-dienes 220.
Scheme 71: Iodination/peroxidation of alkenes 223 with I2 and hydroperoxides.
Scheme 72: The reactions of cyclic enol ethers 226 and 228 with I2/ROOH system.
Scheme 73: Synthesis of 1-(tert-butylperoxy)-2-iodoethanes 231.
Scheme 74: Synthesis of 1-iodo-2-(tert-butylperoxy)ethanes 233.
Scheme 75: Cu-catalyzed phosphorylation–peroxidation of alkenes 234.
Scheme 76: Co-catalyzed phosphorylation–peroxidation of alkenes 237.
Scheme 77: Ag-catalyzed sulfonylation–peroxidation of alkenes 241.
Scheme 78: Co-catalyzed sulfonylation–peroxidation of alkenes 244.
Scheme 79: Synthesis of α/β-peroxysulfides 248 and 249 from styrenes 247.
Scheme 80: Cu-catalyzed trifluoromethylthiolation–peroxidation of alkenes 250 and allenes 252.
Scheme 81: Photocatalytic sulfonyl peroxidation of alkenes 254 via deamination of N-sulfonyl ketimines 255.
Scheme 82: Photoredox-catalyzed 1,4-peroxidation–sulfonylation of enynones 257.
Scheme 83: Cu-catalyzed silylperoxidation of α,β-unsaturated compounds 260 and enynes 261.
Scheme 84: Fe-catalyzed silyl peroxidation of alkenes.
Scheme 85: Cu-catalyzed germyl peroxidation of alkenes 267.
Scheme 86: TBAI-catalyzed intramolecular cyclization of diazo compounds 269 with further peroxidation.
Scheme 87: Co-catalyzed three-component coupling of benzamides 271, diazo compounds 272 and TBHP.
Scheme 88: Co-catalyzed esterification-peroxidation of diazo compounds 274 with TBHP and carboxylic acids 275.
Scheme 89: Cu-catalyzed alkylation–peroxidation of α-carbonylimines 277 or ketones 280.
Scheme 90: Mn-catalyzed ring-opening peroxidation of cyclobutanols 282 with TBHP.
Scheme 91: Peroxycyclization of tryptamines 284 with TBHP.
Scheme 92: Radical cyclization–peroxidation of homotryptamines 287.
Scheme 93: Iodine-catalyzed oxidative coupling of indoles 288, cyanoacetic esters and TBHP.
Scheme 94: Summary of metal-catalyzed peroxidation processes.
Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins
- Mike Brockmann,
- Jonas Lobbel,
- Lara Unterriker and
- Rainer Herges
Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248
- 20 in a yield of 89% [13]. To convert the iodo to an OH group, compound 20 was reacted with Cu2O, 2-pyridinaldoxime and CsOH to give 2-hydroxy-3,4,5-trimethoxybenzaldehyde (21, 65%) [13]. In a subsequent nucleophilic substitution, the fluorinated alkyl chains of 16, 17, and 18 were linked via a
Graphical Abstract
Scheme 1: Synthesis of the starting materials 16, 17, and 18 for the subsequent Williamson ether synthesis wi...
Scheme 2: Synthesis of perfluoroalkyl ester-functionalized aldehydes 22, 23, and 24. Conditions: a) NIS, TFA,...
Scheme 3: Porphyrin synthesis. a) Rothemund porphyrin synthesis of metal-free porphyrins 26, 27, and 28; b) m...
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
- compounds (Scheme 16) [68]. The novel iodine(III) intermediate was generated through nucleophilic substitution of a heteroatom nucleophile, which initiated the reaction. A subsequent aryl migration from the iodine to the heteroatom resulted in the formation of the arylated nucleophile. In addition to
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.
Copper-catalyzed yne-allylic substitutions: concept and recent developments
- Shuang Yang and
- Xinqiang Fang
Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232
- ). Preliminary mechanistic studies have ruled out the 1,3-sigmatropic shift, indicating that the reaction proceeds through a nucleophilic substitution–annulation process of a reactive π-extended copper-allenylidene intermediate (Scheme 43). At the same time, Qi and Xu et al. [79] also realized the dearomative
- spiroannulation of 2-naphthols or electron-enriched phenols under mild conditions with excellent regioselectivities, enantioselectivities and diastereoselectivities (Scheme 44, 43a–g, 44a–q). In addition, the nucleophilic substitution–dearomative cyclization process between indoles and yne-allylic esters can also
- and rearomatization. Arylation by alkynylcopper driven dearomatization and rearomatization. Remote substitution/cyclization/1,5-H shift process. Proposed mechanism. Arylation or amination by alkynylcopper driven dearomatization and rearomatization. Remote nucleophilic substitution of 5
Graphical Abstract
Scheme 1: Copper-catalyzed allylic and yne-allylic substitution.
Scheme 2: Challenges in achieving highly selective yne-allylic substitution.
Scheme 3: Yne-allylic substitutions using indoles and pyroles.
Scheme 4: Yne-allylic substitutions using amines.
Scheme 5: Yne-allylic substitution using 1,3-dicarbonyls.
Scheme 6: Postulated mechanism via copper acetylide-bonded allylic cation.
Scheme 7: Amine-participated asymmetric yne-allylic substitution.
Scheme 8: Asymmetric decarboxylative yne-allylic substitution.
Scheme 9: Asymmetric yne-allylic alkoxylation and alkylation.
Scheme 10: Proposed mechanism for Cu(I) system.
Scheme 11: Asymmetric yne-allylic dialkylamination.
Scheme 12: Proposed mechanism of yne-allylic dialkylamination.
Scheme 13: Asymmetric yne-allylic sulfonylation.
Scheme 14: Proposed mechanism of yne-allylic sulfonylation.
Scheme 15: Aymmetric yne-allylic substitutions using indoles and indolizines.
Scheme 16: Double yne-allylic substitutions using pyrrole.
Scheme 17: Proposed mechanism of yne-allylic substitution using electron-rich arenes.
Scheme 18: Aymmetric yne-allylic monofluoroalkylations.
Scheme 19: Proposed mechanism.
Scheme 20: Aymmetric yne-allylic substitution of yne-allylic esters with anthrones.
Scheme 21: Aymmetric yne-allylic substitution of yne-allylic esters with coumarins.
Scheme 22: Aymmetric yne-allylic substitution of with coumarins by Lin.
Scheme 23: Proposed mechanism.
Scheme 24: Amination by alkynylcopper driven dearomatization and rearomatization.
Scheme 25: Arylation by alkynylcopper driven dearomatization and rearomatization.
Scheme 26: Remote substitution/cyclization/1,5-H shift process.
Scheme 27: Proposed mechanism.
Scheme 28: Arylation or amination by alkynylcopper driven dearomatization and rearomatization.
Scheme 29: Remote nucleophilic substitution of 5-ethynylthiophene esters.
Scheme 30: Proposed mechanism.
Scheme 31: [4 + 1] annulation of yne-allylic esters and cyclic 1,3-dicarbonyls.
Scheme 32: Asymmetric [4 + 1] annulation of yne-allylic esters.
Scheme 33: Proposed mechanism.
Scheme 34: Asymmetric [3 + 2] annulation of yne-allylic esters.
Scheme 35: Postulated annulation step.
Scheme 36: [4 + 1] Annulations of vinyl ethynylethylene carbonates and 1,3-dicarbonyls.
Scheme 37: Proposed mechanism.
Scheme 38: Formal [4 + 1] annulations with amines.
Scheme 39: Formal [4 + 2] annulations with hydrazines.
Scheme 40: Proposed mechanism.
Scheme 41: Dearomative annulation of 1-naphthols and yne-allylic esters.
Scheme 42: Dearomative annulation of phenols or 2-naphthols and yne-allylic esters.
Scheme 43: Postulated annulation mechanism.
Scheme 44: Dearomative annulation of phenols or 2-naphthols.
Scheme 45: Dearomative annulation of indoles.
Scheme 46: Postulated annulation step.
Scheme 47: Asymmetric [4 + 1] cyclization of yne-allylic esters with pyrazolones.
Scheme 48: Proposed mechanism.
Scheme 49: Construction of C–C axially chiral arylpyrroles.
Scheme 50: Construction of C–N axially chiral arylpyrroles.
Scheme 51: Construction of chiral arylpyrroles with 1,2-di-axial chirality.
Scheme 52: Proposed mechanism.
Scheme 53: CO2 shuttling in yne-allylic substitution.
Scheme 54: CO2 fixing in yne-allylic substitution.
Scheme 55: Proposed mechanism.
5th International Symposium on Synthesis and Catalysis (ISySyCat2023)
- Anthony J. Burke and
- Elisabete P. Carreiro
Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227
- nucleophilic substitution reaction between cyanuric chloride and 4-aminophenylphosphonate or 4-hydroxyphenylphosphonate derivatives. These synthesized dopants were used to prepare the modified Nafion membranes using a casting methodology. Almodovar and Tomé reported the synthesis and characterization of nine
Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine
- Alfiya R. Gimadieva,
- Yuliya Z. Khazimullina,
- Aigiza A. Gilimkhanova and
- Akhat G. Mustafin
Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219
- reactions was made. It has been suggested that a nucleophilic substitution of the peroxide oxygen atom occurs in peroxydisulfate [32]. Regarding phenols (Elbs reaction), there is also a nucleophilic substitution of the phenolate ion. For aromatic amines (Boyland–Sims reaction), a neutral nitrogen atom of
Graphical Abstract
Figure 1: Derivatives of 6-methyluracil and 2-hydroxypyridine demonstrating pharmacological activity: 5-hydro...
Scheme 1: Peroxydisulfate oxidation of 6-methyluracil and 1,3,6-trimethyluracil. Сonditions: a) (NH4)2S2O8, 2...
Scheme 2: Peroxydisulfate oxidation of pyridine and 2-hydroxypyridine. Сonditions: a) (NH4)2S2O8, 24% NaOH, 4...
Scheme 3: Potential mechanism of peroxydisulfate oxidation of 6-methyluracil and 1,3,6-trimethyluracil.
Phenylseleno trifluoromethoxylation of alkenes
- Clément Delobel,
- Armen Panossian,
- Gilles Hanquet,
- Frédéric R. Leroux,
- Fabien Toulgoat and
- Thierry Billard
Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207
- trifluoromethoxylation by nucleophilic substitution, using an excess of DNTFB as a reservoir of CF3O− [68]. Thus, by adding cyclohexene (1a) to the preformed mixture of DNTFB (2 equiv) and DMAP (1 equiv), followed by the addition of PhSeCl, only a low yield of the expected α-trifluoromethoxylated,β-phenylselenylated
- are difficult to synthesize by nucleophilic substitution, such as products 5a and 5b [68]. Conclusion In this work, an efficient phenylseleno trifluoromethoxylation of alkenes has been developed to readily obtain β-selenylated trifluoromethoxylated compounds. These compounds can also undergo radical
- deselenylation to provide trifluoromethoxylated molecules that can be difficult to access by nucleophilic substitution. These results contribute to the further valorization of the DDPyOCF3 salt (arising from DNTFB/DMAP) as an efficient tool in organic fluorine chemistry. Experimental Typical procedure: Synthesis
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...
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
- corresponding thiol [35][36][37][38], in the nucleophilic substitution reaction in the aromatic ring of catechol [39][40] or under electrochemical conditions [41][42][43]. An anodic activation of catechols in the presence of a thiol leads to S-functionalized catechols with triazole, triazine, pyrimidine
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...
