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Search for "redox" in Full Text gives 447 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds
Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200
- , tolerates a variety of functional groups, and offers a wide substrate scope. Under the optimized conditions, Rb2CO3 provided better results than DMAP and Cs2CO3. The acyl azolium complex B was synthesized from acyl imidazole 9 using an NHC and Rb2CO3 as the base. Considering the redox potential of 4CzIPN
- organophotocatalyst (3DPAFIPN) was employed, significant amounts of cyclized product were observed and suggesting that the necessary redox potentials fall near its redox range (E1/2 PC*/PC•− to E1/2 PC/PC•− = +1.09 to −1.59 V vs SCE). This catalytic method provides an efficient route for synthesizing complex
Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies
Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198
- successfully accomplished via an epoxide ring-opening/tandem lactonization/olefin hydration sequence. In total, 12 consecutive redox manipulations (7 oxidations and 5 reductions) established all stereocenters, with subsequent functional group transformations completing the total synthesis of garajonone (8
Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity
Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195
- mechanisms including elevation of reactive oxygen species (ROS) or interference with redox homeostasis, and inhibition of kinase or topoisomerase activities essential for cancer cell proliferation. The selective activity of thiouronium salts against cancer cells compared to non-malignant cells can be related
Synthesis of the tetracyclic skeleton of Aspidosperma alkaloids via PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction
Beilstein J. Org. Chem. 2025, 21, 2470–2478, doi:10.3762/bjoc.21.189
- -initiated [2 + 2] cyclization of the tryptamine-substituted cyclobutenone K to form the radical cation L, which has a highly functionalized and rigid bicyclo[2.2.0]hexane core. Fragmentation of the C3–C19 bond would afford a redox-active intermediate which upon further reductive quenching would lead to the
Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications
Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179
- bulky stoppers at both ends to prevent dethreading (Figure 1) [1][8]. Functionalization of the axle with recognition sites allows the macrocycle to shuttle between positions in response to external stimuli, including light, redox, temperature, pH, and reactions with chemicals such as carbodiimides [9
Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177
- converting the biradical to the corresponding zwitterion; (3) oxy-cyclization to afford the product. This process constitutes an intramolecular redox reaction, wherein the quinone is reduced to a hydroquinone while the proximal C–H bond is oxidized to a C–O bond. Although related photoredox reactions had
Enantioselective radical chemistry: a bright future ahead
Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174
- abundance, low cost, less toxicity, and existence of multiple oxidation states (I, II, and III) make copper an essential transition metal for catalytic purposes [60][61]. The fact that copper, like other transition metals, has multiple oxidation states makes it an excellent redox catalyst. Owing to the
- was the use of ferrocene as a redox mediator, which played an important role in preventing substrate decomposition under the electrochemical conditions. An electrochemical method enabled regio- and enantioselective radical reactions of silyl polyenolates with racemic α-branched esters, yielding
Pathway economy in cyclization of 1,n-enynes
Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173
- enabling more efficient utilization of limited raw materials [1][2]. Two years later, Wender proposed “step economy” advocating optimized synthetic routes and strategies to minimize the number of steps required for constructing target molecules [3][4]. In 2008, “redox economy” was introduced by Baran [5
- ]. Similar to “atom and step economies”, this concept emphasizes prioritizing the minimization of redox manipulations during synthesis to achieve linear and stable progression of oxidation states in intermediates. In recent years, “pot economy” and “time economy” were proposed by Hayashi, underscoring the
- circumvents cumbersome late-stage functional group manipulations and perfectly aligns with the principles of step economy, time economy, and redox economy. Over the past few decades, chemists have rapidly directed this efficient synthetic paradigm toward diverse targets by skillfully regulating reaction
Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings
Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166
- transformations far from thermodynamic equilibria have emerged abundantly with the consideration of green chemistry [89][90][91][92]. Redox-active organic compounds, transition metal coordinating compounds and even an electrode surface were commonly employed as catalysts in the electrochemical transformations [93
- ]. Besides, electrochemical cyclization of alkynes is also an important access towards indoles. In 2016, Xu reported the electrochemical intramolecular coupling of urea derivatives to form substituted indoles (Scheme 1) [162]. Using [Cp2Fe] (5 mol %) as the redox catalyst, the intramolecular coupling of
- cationic resonance G quickly. The nucleophilic attack of D2O formed H, which underwent dedeuteration and elimination of DI to form 30a with reduction of deuterated water to generate deuteroxyl ions (OD−) and deuterium gas (D2) at the cathode. This method, using iodide salts as electrolyte and redox
C2 to C6 biobased carbonyl platforms for fine chemistry
Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165
- Meerwein–Ponndorf–Verley reduction, while acetaldehyde is generated in situ by ethanol oxidation (Scheme 50). The equilibrium allows furfural to be simultaneously converted into furfuryl alcohol and 3-(2-furyl)acrolein in one pot through a redox reaction. The highest mass conversion rate of furfural can
Multicomponent reactions IV
Beilstein J. Org. Chem. 2025, 21, 2082–2084, doi:10.3762/bjoc.21.163
- a strong emphasis on heterocycle synthesis. Beyond traditional condensation-based approaches, mechanistically innovative crossovers – linking metal catalysis with radical chemistry and, more recently, with photo(redox) catalysis – are opening entirely new avenues for MCR development. Finally, seven
Bioinspired total syntheses of natural products: a personal adventure
Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160
- approach. This key reaction mimics the plausible biosynthetic pathway and demonstrates great efficiency and sole diastereoselectivity, showcasing the plausibility of the biosynthetic proposal. Further redox manipulations of the last olefin and deprotection ultimately provided chabranol. To clearly confirm
- oxa-carbenium cation triggered by an acid to proceed a Friedel–Crafts reaction to afford the dibenzocyclooctene skeleton. On the other hand, eupomatilone would undergo redox transformations to generate another oxa-carbenium cation to undergo a Friedel–Crafts reaction to form a spirocyclic skeleton
Photochemical reduction of acylimidazolium salts
Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153
- acid derivative substrates [16]. Over the last few years, a wide range of valuable NHC-catalyzed transformations have also been developed that incorporate redox steps. As an enamine species, single-electron oxidation of a Breslow intermediate is comparatively favored with the resulting open shell
- direct excitation of the benzoylazolium salt with the excited state species 1*, which subsequently reacts with TESH. Comparison of the redox potential of the silane (+1.54 V vs ferrocene) with the estimated excited-state potential of the azolium salt 1* (+1.70 V vs ferrocene) suggest that direct electron
Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151
- diastereoselectivity. Compound 288 was then treated with Co(acac)2, 1,1,3,3-tetramethyldisiloxane (TMDSO), and O2 in degassed iPrOH, undergoing a hydrogen-atom-transfer (HAT)-initiated redox radical cascade to give pentacyclic alcohol 289, which was converted to C18/19 diol 290 in two steps. To differentiate the two
Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation
Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149
- -bridged structural analogs of [1n]metacyclophanes. In comparison to all-carbon [1n]metacyclophanes, the incorporation of N atoms endows them with unique features, such as enhanced molecular dynamics and tunable redox property, positioning them as key precursors to construct organic high-spin materials [20
Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs
Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148
- alkylating agents 1–3. The motivation behind these experiments was to explore whether these compounds, which individually exhibit no appreciable redox activity in the potential window applied, can chemically modify (alkylate) serum albumin and thus suppress its characteristic oxidation peaks. Human serum
- themselves exhibit no discernible redox activity in this potential range when tested in the absence of HSA. Consequently, any changes in the recorded voltammogram could be attributed to the interaction (alkylation) of albumin rather than to new electrochemical processes arising directly from the compounds
Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines
Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147
- voltammetry measurements were also carried out in order to evaluate the electrochemical redox properties of the species involved in the process and to provide evidence for the behavior of the monoprotonated and the bisprotonated diimines, 3a and 4a (Scheme 8). The cyclic voltammogram of the starting diimine
Research progress on calixarene/pillararene-based controlled drug release systems
Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139
- times. This bis-vesicle structure possesses the following intelligent responsive characteristics: (1) temperature sensitivity originating from the enthalpy-driven nature of the host–guest interaction; (2) redox responsiveness due to the reversible electron transfer of MVC12; (3) competitive complexation
- making the system sensitive to cyclodextrins. Experiments have confirmed that this carrier can efficiently encapsulate DOX and trigger drug release through multiple stimuli, demonstrating good potential for anticancer therapy in vitro. This intelligent delivery system, integrating temperature, redox, and
Photocatalysis and photochemistry in organic synthesis
Beilstein J. Org. Chem. 2025, 21, 1645–1647, doi:10.3762/bjoc.21.128
- ) transition, resulting in a long-lived charge-separated species. In this excited state, [Ru(bpy)3]Cl2 is both a more potent oxidant and reductant than in its ground state. This reactivity, in combination with the reversible redox behavior of the metal complex, enables reductive or oxidative quenching cycles
Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads
Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121
- energy gap between them. Phenothiazine (PTZ) and perylene (Pe) are well-known molecular components for designing π-orthogonal D–A systems [13][14][15]. PTZ is an excellent electron donor due to its strong electron-donating ability and redox tunability, while Pe is often used as a robust acceptor
Azobenzene protonation as a tool for temperature sensing
Beilstein J. Org. Chem. 2025, 21, 1528–1534, doi:10.3762/bjoc.21.115
- emerged as staple building blocks in smart materials, from light-responsive norbornadienes in molecular solar thermal energy storage [2] to pH-sensitive spiropyrans in cell imaging [3], and redox-active viologens in memory junctions [4]. Among the different molecular switches azobenzenes stand out due to
Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications
Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106
- versatile scaffolds for chiral optoelectronic applications. The incorporation of nitrogen enables precise modulation of electronic structures, redox characteristics, and intermolecular interactions, thereby enhancing performance in circularly polarized luminescence (CPL), thermally activated delayed
- fluorescence (TADF), and chiral sensing. Notably, recent developments have yielded π-extended, structurally robust, and stimuli-responsive azahelicenes exhibiting record-high dissymmetry factors (|gabs| and |glum|), elevated CPL brightness (BCPL), and efficient integration into CPL-OLEDs and redox-switchable
- structures, enhance solubility, and expand functional diversity [6]. Substituting carbon atoms with electron-deficient nitrogen atoms introduces new opportunities to fine-tune redox potentials, charge-transport behavior, and intermolecular interactions [7]. These modifications have proven especially valuable
Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes
Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99
- (89%). Interestingly, the fusion of two azulene units at peri-position induces the significant orbital interaction, resulting in a very narrow HOMO–LUMO gap in 172. Consequently, 172 exhibits NIR absorption properties (λmax = 1180 nm, tail to 1720 nm) and reversible redox behaviours (electrochemical
Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents
Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98
- radical C, which adds to the N-arylacrylamide, followed by intramolecular cyclization and deprotonation to form the final products 19. To further expand the radical difunctionalization toolbox, electrochemical approaches have emerged as a green and efficient alternative, offering precise redox control
- employed as a redox catalyst, Na2CO3 as a base, and n-Bu4NBF4 as the electrolyte, all participating in an undivided electrolytic cell with a reticulated vitreous carbon (RVC) anode and a platinum (Pt) cathode at a constant current of 10 mA, in a co-solvent mixture of MeOH/THF 2:1 for 3 hours to deliver the
- selection, solvents, and current density, the best results were obtained using tetrabutylammonium bromide as the catalyst in CH₃CN, with a low catalyst loading of 2 mol %, and palladium wire as the cathode, yielding the target compound in 81% yield. This study capitalized on the use of bromide ions as redox
Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates
Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96
- -centered radical from diisopropyl H-phosphonate (2a). In addition, the anion affects the redox properties of the copper ion, and thus the optimal choice is important to achieve both sufficient oxidative properties and catalyst recycling by reoxidation with O2. The employment of Mn(acac)3 and FeCl3, which
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