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Search for "efficiency" in Full Text gives 1228 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles
Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194
- ring itself to also include benzophenanthridine, dibenzonaphthyridine, and benzophenanthroline heterocycles of previously unreported identity (Figure 2). In addition to studying how naphthalene, quinolone, and isoquinoline incorporation impact click and annulation efficiency, characterizing the
- isoquinoline subunits. Heterocycle subunit identity and triazole C/N connectivity influenced the annulation reaction efficiency. Aromatic π-system expansion resulting from annulation was characterized by NMR, absorption and emission spectroscopy. Five benzotriazolophenanthroline regioisomers sharing structural
Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions
Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192
- bilayers through the shuttling of the macrocycle carrying the ions or through a relay mechanism [10][11]. In one example, the isomerization of an azobenzene photoswitch incorporated into the axle was used to modulate the shuttling rate of the macrocycle and, consequently, the efficiency of potassium ion
Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate
Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191
- cleavage of the S–S bond and the subsequent S-alkylation reaction were successful. To suppress the side reaction and improve reduction efficiency, we next employed DMF as a polar aprotic solvent. In Table 2, entry 4, reduction of disulfide 3 in DMF at 75 °C with NaBH4 was complete within 15 min. The excess
Palladium-catalyzed regioselective C1-selective nitration of carbazoles
Beilstein J. Org. Chem. 2025, 21, 2479–2488, doi:10.3762/bjoc.21.190
- were ineffective in improving the reaction outcome (Table 1, entry 6). Other palladium complexes promoted the formation of 2a but with diminished efficiency (Table 1, entries 7 and 8). Varying the amount of AgNO3 did also not lead to a better yield (Table 1, entry 9), and alternative nitro sources also
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
- University, Liaoning Shenyang 110016, China 10.3762/bjoc.21.189 Abstract Natural products with topologically complex architectures are important sources in drug discovery. The pursuit of conciseness and efficiency in the total synthesis of natural products promotes continuous innovation and the development
Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds
Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185
- . Irritation of a solution of 124 in CH3OH using a medium-pressure Hg lamp resulted in the formation of methyl ester 125 as a single diastereomer with a yield of 30%. Due to the decrease in the efficiency of this reaction at higher loads (>50 mg), the thermal conditions for the Wolff rearrangement were tested
The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions
Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184
- all of the above criteria. For example, it can be synthesized easily and with high efficiency through the biodiesel production process, it can be reused, it is stable under storage conditions, it can be obtained from renewable resources, it is biodegradable, non-flammable etc. It is widely
An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives
Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183
- desired reaction [17]. Under these conditions, the reaction was performed on a 5 mmol scale without any loss of efficiency. We next evaluated the scope of the developed protocol. The electronic and steric nature of substituents had a minimal impact on the product yields and in most cases, the desired
Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs
Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181
- fluorescence quenching efficiency upon iodide binding compared to the rigid WDG (KPBG/KWDG = 22.78), demonstrating its potential as a highly sensitive optical probe and offering a novel strategy for engineering dynamic supramolecular receptors. Two carbazole-based macrocyclic probes, PBG (flexible benzene ring
- cavity, which may not perfectly complement iodide's size or geometry, leading to weaker interactions and a higher-energy (less stable) complex. This energy difference aligns with the observed higher binding constant (K) of PBG, demonstrating that structural flexibility enhances anion-binding efficiency
Adaptive experimentation and optimization in organic chemistry
Beilstein J. Org. Chem. 2025, 21, 2367–2368, doi:10.3762/bjoc.21.180
- analyze experiments using machine learning optimization algorithms [5][6]. Together, these capabilities are dramatically increasing the speed and efficiency of chemical optimization with respect to economic and environmental objectives [7]. The contributions in this thematic issue showcase innovative
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
- experimental and theoretical studies involving these rotaxanes showed that no side reactions occur upon excitation, meaning these compounds can be operated continuously under illumination with very little efficiency loss, making them very effective photoactive units in nanodevices. In 2005, Leigh and co
- -stilbenes have 5-membered rings fused to the carbon–carbon double bond, are more photostable, and undergo reversible photoisomerization with higher efficiency (Figure 2) [75]. Notably, their cis isomer exhibits higher thermal stability than that of other commonly used photoswitches, such as azobenzene. This
- dithienylethene is in the closed form, caused by photoinduced electron transfer (PET) from the fluorescent pyrene stopper to the acceptor dithienylethene (Figure 15). Moreover, the efficiency of the PET is modulated by the macrocycle shuttling motion between the two recognition sites due to differences in
Comparative analysis of complanadine A total syntheses
Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178
- efficiency and step-economy of natural product total synthesis. This symbiotic relationship has also helped to accelerate natural product biological evaluation and the subsequent biomedical development [1]. Lycopodium alkaloids are one of the largest families of natural products [2], from which famous
- and co-workers [19]. In this review article, we summarize these four total syntheses, comparatively analyze their strategic novelty and differences, and highlight the impact of enabling methodologies and concepts on the overall efficiency and economy of each total synthesis [20]. Review The Siegel
- and different approaches were developed. The Siegel synthesis harnesses the power and efficiency of two Co-mediated [2 + 2 + 2] cycloadditions to build the C2–C3’-bipyridyl moiety encoded by complanadine A. The Sarpong synthesis leverages a biomimetic approach to rapidly assemble the tetracyclic core
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
- key late-stage step in this total synthesis, the Norrish–Yang photocyclization exhibits high chemoselectivity and efficiency. It regulates selectivity through C–H bond dissociation energy and restricted bond rotation, constructing a 6/6/4 fused ring system with three contiguous quaternary carbons
- . Moreover, the reaction can be performed on a 300 mg scale, balancing selectivity, efficiency, and practicality. 1.2 Synthetic study toward phainanoids Phainanoids are highly modified triterpenoids first isolated from Phyllanthus hainanensis by Yue's group [24][25]. Biologically, these molecules exhibit
- epimers. This strategy merges photochemical selectivity with cross-coupling efficiency, avoiding reactive metal incompatibility and enabling precise stereocontrol for chiral nitrogen heterocycles. 3 Antibiotics 3.1 Synthetic study toward γ-rubromycin Since 2017, Suzuki's group has developed a
Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes
Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176
- structures for G2W1 and G2W3 suggest that the OMe groups fill their own cavity and thereby decrease their abilities as sequestrants. H2 achieved a removal efficiency of 94% for methylene blue whereas G2W1 demonstrated a 64% removal efficiency for methylene violet; both sequestration processes were largely
- due to its simplicity, efficiency, low cost, and the absence of hazardous byproducts [6]. Many different adsorptive materials have been investigated including activated carbon [7][8][9], hybrid nanomaterials [10], metal oxide-based hybrid materials [11], metal organic frameworks [12], polymers [13
- (Figure 2) from water. Subsequently, we present the X-ray crystal structures of G2W1 and G2W3 which helps rationalize the results from the dye sequestration experiments. Finally, we present a detailed investigation into the methylene blue removal efficiency using H2 [39] (Figure 1) and the methylene
Enantioselective radical chemistry: a bright future ahead
Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174
- chemical oxidant or reductant [80][85], thereby reducing toxicity and waste. With these advantages, organic electrochemistry holds significant promise for improving efficiency and sustainability while enabling the development of new transformations. Meggers and co-workers developed an electrochemical
- for applications in radical chemistry. Compared with conventional batch synthesis, flow chemistry can improve efficiency and facilitate reaction scale-up [87][88][89][90]. Mechanochemistry allows reactions to be conducted with no solvent or with only a small volume of added liquid, thus providing a
Pathway economy in cyclization of 1,n-enynes
Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173
- substrate class. Through mechanistic-guided modulation of catalysts, solvents, ligands, and angle strain, this approach achieves unprecedented reaction pathway control while demonstrating superior temporal and step efficiency compared to conventional methods. The work establishes a sustainable framework for
- transition states. This integrated control framework provides a rational basis for designing reaction conditions to optimize selectivity and efficiency in organic synthesis. In 2014, the Liu group developed an Au(I)-catalyzed cascade cyclization strategy for synthesizing polysubstituted naphthalenes using
- ligands could enhance catalytic activity and efficiency while enabling fine control over chemo-, regio-, stereo-, and enantioselectivity of reactions. Ligands enhance both the thermal/chemical stability and solubility profiles of catalysts in specific reaction media. Thus, ligands function as a regulatory
Pd-catalyzed dehydrogenative arylation of arylhydrazines to access non-symmetric azobenzenes, including tetra-ortho derivatives
Beilstein J. Org. Chem. 2025, 21, 2234–2242, doi:10.3762/bjoc.21.170
- efficacious but face significant challenges when applied to non-symmetric systems [24], particularly in achieving regioselectivity. These methods frequently require a particular reagent pair or an excess of one reactant, which limits their efficiency and versatility. In contrast, Baeyer–Mills reactions, which
- efficiency, as the reaction proceeds smoothly even when both coupling partners possess sterically hindered substituents at the 2,6-positions. For example, the coupling of 2,6-difluorophenylhydrazine with 1-bromo-2,6-dimethoxybenzene yielded tetra-ortho-substituted azobenzene 5a in a notable yield of 63
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
- ][94]. Electrochemical transformations used renewable and clean electricity as a source of electrons and electron holes to generate radical species, showing several superiorities such as safety, economy, high selectivity, scalability, mild reaction conditions, powerful efficiency, environment-friendly
C2 to C6 biobased carbonyl platforms for fine chemistry
Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165
- impact while maintaining the efficiency of the chemical processes [1]. Green Chemistry principles outlined by Anastas and Warner in their work “Green Chemistry: Theory and Practice (2000)” [2] notably highlight atom economy, waste minimization and the use of renewable feedstock as pillars of sustainable
- ). Partial γ-acyloxy-Cy7 possesses a high fluorescence quantum yield and high photothermal conversion efficiency in PBS, two pivotal parameters in fluorescence imaging and image-guided photothermal therapy [196]. A dimerization of furfural has been found to occur at the early stage of formation of humins
- rehydration into levulinic acid (Scheme 70, route b1). It is now preferred considering raw material costs, process efficiency and market demand. Alternatively, C6 monosaccharides can also be fermented to produce pyruvic acid and acetaldehyde, which combine by an aldol reaction and lead to levulinic acid by
The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products
Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164
- . We hope this review can stimulate the methodology development and application of this strategy toward further improving the synthetic efficiency of natural product synthesis. Review Total synthesis of terpenoid and alkaloid natural products through the desymmetric enantioselective reduction of five
- for the synthesis of (+)-26 to complete the first total synthesis of (+)-chamaecydin (27). The successful collective total synthesis of the two structurally complex natural products demonstrated the high efficiency of the modular synthetic strategy based on the desymmetric enantioselective reduction
- efficiency was significantly improved. Despite remarkable progress has been made, there is still a long way to go before the strategy achieves maturity for applications in natural products. Specifically, challenges remain in improving the enantioselectivity and diastereoselectivity of the desymmetric
Further elaboration of the stereodivergent approach to chaetominine-type alkaloids: synthesis of the reported structures of aspera chaetominines A and B and revised structure of aspera chaetominine B
Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162
- confirmation of natural products is no longer a motivation for the total synthesis [1]. Nevertheless, we also witness that each year, cases continue to be reported on the total synthesis enabled revision of misassigned structures of natural products [1][2][3][4][5][6][7][8][9]. Efficiency is one of the major
- cyclization of an intermediate derived from ᴅ-tryptophan [60][61]. Subsequently, we developed a five-step total synthesis of (–)-chaetominine (1) and two diastereomers from ʟ-tryptophan [62]. Taking advantages of the high efficiency and flexibility of our strategy [60], we have synthesized several natural and
- than those using (COCl)2/DIPEA in our previous synthesis of isochaetominines [63]. We realized that employing this lactamization protocol would significantly improve the synthetic efficiency of isochaetominines 4–6. To showcase this possibility, the improved lactamization protocol was applied to
Bioinspired total syntheses of natural products: a personal adventure
Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160
- the synthetic steps and gain efficiency. More significantly, since the exact biosynthetic pathway of a natural product is generally very complicated and hard to elucidate clearly, a biosynthetic pathway is basically proposed by the isolating scientist according to the structural analysis of the
- synthesis probably lead this field to the lane of scientific logic, which would provide guidelines to design a bioinspired strategy. Our group has a long-time of research experience on complex natural product synthesis. To achieve higher efficiency of synthesis, we inevitably exploited the concept of
- 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
Solar thermal fuels: azobenzene as a cyclic photon–heat transduction platform
Beilstein J. Org. Chem. 2025, 21, 2036–2047, doi:10.3762/bjoc.21.159
- visible light under sunlight irradiation [59], achieving a solar efficiency of 0.4% and a solid-state isomerization efficiency of 72.7% (Figure 5b). Feng and co-workers reported the synthesis of three azopyridine polymers (ortho-, meta-, and para-) [60], with the m-azopyridine polymer exhibiting a
- development of azobenzene-based solar thermal fuels and demonstrated their potential applications. Nanocarbon-integrated azobenzene polymers: Their energy storage efficiency (up to >200%) and cycle life are primarily modulated by template confinement effects and electronic coupling. However, high costs and
- , and hinders practical deployment. Third, azobenzene groups release energy through a process involving thermal relaxation or thermally induced cis–trans isomerization. Temperature critically governs the efficiency and kinetics of this process: elevated temperatures accelerate uncontrolled instantaneous
Photochemical reduction of acylimidazolium salts
Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153
- changed from 440 nm (blue LEDs) to 370 nm (UV-A). This resulted in an overall improvement in the reduction efficiency with the fully reduced species 2 becoming the major product formed in 38% yield alongside the O-benzoylated species 3 (9%, Table 1, entry 5). This result is again remarkable in that it
- efficiency observed upon switching from blue to UV-A light irradiation. Nevertheless, alternative scenarios involving the potential formation of excited donor–acceptor (EDA) complexes between benzoylazolium species 1 and DIPEA were considered. Measurements of the UV–vis spectra in the presence of the amine
- products 2 or 3 limits the overall efficiency. To overcome this limitation, we considered whether a different approach could provide reduced products in yields greater than 50% relative to the starting material 1. In particular, addition of chloro(trimethyl)silane (TMSCl) to the reaction mixture could
Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization
Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152
- was treated with p-toluenesulfonic acid (p-TSA) in EtOH at room temperature to afford ketal 24 in 83% yield as a single diastereomer. Subsequently, palladium-catalyzed decarboxylative allylation delivered compound 25 in 89% yield. The efficiency of our first-generation strategy for asymmetric
- synthesis of 4 was unsatisfactory because it required nine steps to prepare bicyclic intermediate 25 with an overall yield of just 2.0%. This low efficiency prompted us to develop a more streamlined synthetic route for target compound 4. Second generation asymmetric total synthesis of tricyclic-PGDM methyl
- ester Although the efficiency of the first-generation asymmetric total synthesis strategy was limited, the development of synthetic methods during this work, particularly the transition-metal-mediated oxidative radical cyclization for stereoselective assembly of the cyclopentanol scaffold bearing the C8
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