Search results
Search for "ester" in Full Text gives 1513 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Synthesis of diaryl phosphates using phytic acid as a phosphorus source
Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15
- rely on phosphate rock but instead uses biomass as a phosphorus source. Keywords: diaryl phosphates; phosphate esters; phosphate ester synthesis; phosphorus recovery; phytic acid; Introduction Phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, Scheme 1) is a phosphorus-rich molecule, which is
- phosphates [16]. Drugs and reagents containing phosphate ester moieties were designed as analogs of these molecules [16][17][18][19][20]. Phosphate monoesters with long aliphatic chains have also been used as surfactants [21]. Phosphate triesters are utilized as flame retardants and plasticizers for polymers
- esterification with alcohols using sustainable biomass-derived phytic acid as a phosphorus source (Figure 2E). This approach can facilitate the development of environmentally friendly phosphate ester production as well as phosphorus recovery and recycling techniques. To date, the preparation of phosphate esters
Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation
Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13
- migration in the formed tetrahedral intermediate to afford formate ester; c) hydrolysis of the latter to form phenols [28]. The development of methods for the construction of heterocycles and their modification is an important area of organic synthesis [29]. Although the Dakin oxidation has become a
Circumventing Mukaiyama oxidation: selective S–O bond formation via sulfenamide–alcohol coupling
Beilstein J. Org. Chem. 2026, 22, 158–166, doi:10.3762/bjoc.22.9
- conditions, the selective S–O bond formation has been largely overlooked, rendering the direct synthesis of sulfinimidate esters from alcohols a nontrivial and underdeveloped transformation. Results and Discussion To validate our hypothesis and identify optimal conditions for sulfilimidate ester formation
- bearing an iodoalkyl side chain provided the product 3w’ in 39% yield. Also a hydroxy-functionalized alcohol, derived from prop-1,3-diol, afforded the corresponding sulfinimidate ester 3x’ in 35% yield under the standard conditions (conditions d), where 2.5 equivalents of the alcohol, NBS and NaHCO3 were
- with improved chemoselectivity toward monosubstitution and the yield of product 3x’ increased to 64%. Notably, although ester 3x’ contains two hydroxy groups, no bis-substituted product could be detected under either set of conditions. To demonstrate the practicality and synthetic utility of this
Asymmetric Mannich reaction of aromatic imines with malonates in the presence of multifunctional catalysts
Beilstein J. Org. Chem. 2026, 22, 151–157, doi:10.3762/bjoc.22.8
- stirred at room temperature until a suspension was formed (ca 5 min). After that, the reaction mixture was cooled to −20 °C. The malonic ester (0.171 mmol, 3.0 equiv) was added to the reaction vessel via syringe. The reaction was stirred at −20 °C for an appropriate time. The progress of the reaction was
Total synthesis of natural products based on hydrogenation of aromatic rings
Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4
- % yield over two steps [76]. Alkylation with MeI furnished pyridinium 91, which was hydrogenated in two steps with NaBH3CN to the fully saturated piperidine 92. Acidic removal of the benzoyl group triggered auto-oxidation to the indole, and subsequent hydrolysis of methyl ester delivered the target
- , Johnson–Claisen rearrangement, enol ester formation, and methylation afforded 140. Finally, hydrogenation of 140 via PtO2/H2 generated the target molecule (±)-corynoxine, and under acidic conditions, (±)-corynoxine could be isomerized to (±)-corynoxine B (Scheme 19). Total synthesis of (+)-serratezomine E
Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene
Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2
- reactions mainly involve the initial electrophilic attack onto the α-position relative to the hydrogen atom. The selectivity is either due to the high stability of the α-nucleophilic conformer or due to the promotion by the adjacent ester group. Cascade reactions upon the target connection, if installed
- planarity of the two neighboring ester groups and thereby stabilize the anion. The prevalence of this isomer is also confirmed by the NMR data [21], however, other conformers with different charge distributions are also available in solution. To understand the nucleophilic reactivity of the most stable
- 11. The 1,5-arylazo shift has been previously investigated in cyclopentadiene systems [32]. Subsequent formation of norcaradienes 12 and azocyclopropane rearrangement [33][34][35] afford a mixture of isomeric dihydroindazole derivatives 8 and 9 which differ in positioning of one ester group. The
Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review
Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1
- also be applied to hydroxy- or carboxylic acid-containing olefins by adding 1.1 equivalents of HB(pin) to perform traceless protection of these functional groups, which are otherwise incompatible with molybdenum metathesis catalysts. The in situ-generated boronic ester is conveniently cleaved by silica
One-pot synthesis of ethylmaltol from maltol
Beilstein J. Org. Chem. 2025, 21, 2755–2760, doi:10.3762/bjoc.21.212
- commenced our investigation with acetylation of maltol (2) using acetic anhydride to afford ester 8a. Unfortunately, the acetate group proved labile upon treatment of 8a with lithium bis(trimethylsilyl)amide (LiHMDS), resulting exclusively in deprotection to give maltol (2, Table 2, entry 1). Turning to the
Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides
Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211
- -nitro-2-nitrosopropanoates (1g and 1h), which contain an additional electron-withdrawing ester group in geminal position. Finally, 1-nitrosocyclohexane-1-carbonitrile (1i) was also tolerated under the reaction conditions, affording product 2i in 61% yield. The robustness of the developed protocol was
Total synthesis of asperdinones B, C, D, E and terezine D
Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210
- bond formation and functional group compatibility presented unforeseen challenges. Methods for the chemical synthesis of prenyltryptophans (approach A, A–C) are scarce [25][26]. Adopting a bio-inspired approach, Ishikawa et al. treated tryptophan ethyl ester with prenyl alcohol in the presence of 2
- amorphous powder. Viswanathan [25] and Chen [28] reported a C-2 prenylation of tryptophan methyl ester mediated by acid salts and Lewis acids, respectively. A prenylation at C-4 in bis-N-Boc-tryptophan methyl ester has been achieved by Chein utilizing optimized Suzuki coupling conditions [29]. Results and
- alternative approach to C-7 functionalization of Nα-Boc-tryptophan methyl ester, we chose a CH activation protocol [33]. Treatment of N1-Piv-Nα-Boc-tryptophan methyl ester (10) with but-3-en-2-one (MVK) in the presence of [RhCp*Cl2]2 catalyst according to Ma et al. [34] led to the 7-(3-keto-1-butyl)-alkylated
Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones
Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209
- are cyclized with aldehydes and ammonia (monoamines) or urea to yield a certain type of products only: pyridines and pyrimidines; and formation of the products proceeds with the involvement of an acyl fragment and the meso-position of an oxo ester component [9]. Although the introduction of 2
- for 3-polyfluoroalkyl-3-oxo esters containing an activated carbonyl group capable of adding α-methylene ketones. It is characterized by the cyclization at the 1,3-dicarbonyl fragment of 3-oxo ester and offers a possibility of using a variety of nucleophilic agents to form hydrogenated diastereomeric
- a microwave (MW) reactor (Table 1, entry 6). It turned out that after 24 hours of heating the complete conversion of oxo ester 1 occurred and the overall yield increased to 83% (Table 1, entry 5), whereas the use of MW reduced the reaction time down to five hours (Table 1, entry 6), but the contents
Recent advancements in the synthesis of Veratrum alkaloids
Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206
- -methylene group and an ester reduction/Appel reaction sequence to convert the ester moiety to an iodide leaving group. The right-hand fragment (E/F-ring) was synthesized from tert-butylsiloxyfuran 39. Commencing via an asymmetric allylic alkylation and an aza-Michael reaction, butanolide 40 was obtained in
- (12), only one synthesis is reported [14]. The Masamune group disclosed this synthesis in 1968, starting with a sequential ring construction of the C, B and A-ring from Hagemann’s ester (61) to C-nor-D-homo steroid precursor 62 (Scheme 13). The piperidine F-ring was then coupled after D-ring
- oxidation and the double bond installation mentioned, including several redox manipulations and protecting group removals. In total, the Masamune group reported the total synthesis of jervine (12) from Hagemann’s ester (61) in 47 steps in the LLS and a total of 49 steps. Not all yields were reported, so no
Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system
Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205
- ): reduction of 8 with NaBH4, followed by chlorination of alcohol 36 with SOCl2 and substitution of chloro derivative 37 with various amines resulted in compounds 38a–c. Tianeptine analogue 38d was obtained by hydrolysis of ester 38c. The synthesis of the new regioisomeric tetracyclic compounds containing the
- regioselectivity. Reduction of 51 with NaBH4 and subsequent chlorination of alcohol 52 with SOCl2 gave chloro derivative 53, which was treated with amines to afford compounds 54a–e. 7-Aminoheptanoic acid ester derivative 54e was hydrolyzed to tianeptine analogue 54f. Conclusion As continuation of our efforts to
- (1 Cl); HRESIMS (m/z): [M + H]+ calcd for C25H32ClN2O6S, 523.1664; found, 523.1668. 7-[(9-Chloro-6-methyl-7,7-dioxido-2,3,6,12-tetrahydro[1,4]benzodioxino[6,7-c]benzo[f][1,2]thiazepin-12-yl)amino]heptanoic acid (21b): To a solution of ester 21a (2.615 g, 5 mmol) in EtOH (30 mL), NaOH (0.240 g, 6 mmol
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
- , particularly the synergistic combination of N-heterocyclic carbenes (NHCs) with organic photocatalysts, has opened new avenues in molecular construction, particularly for the novel, practical preparation of carbonyl group-containing compounds [13][14][15][16]. These ubiquitous ketone, ester, and amide
- presence of NHC (10 mol %) and 4CzIPN (2 mol %) and Na2HPO4 in DMSO at rt for 10–24 h. The key to success lies in the photocatalytic dual system, which combines two organocatalysts (NHC/4CzIPN) and visible light irradiation to permit a novel umpolung single-electron reduction of respective imino ester 2
- arylcyclopropanes 5 by applying NHC/ photoredox cooperative organocatalysis under visible-light irradiation. This method allows sequential C–O and C–C bond formation, leading to access to various γ-aroyloxy keto-ester derivatives 6 in good yield up to 81% and excellent functional group tolerance, including electron
Recent advances in total synthesis of illisimonin A
Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199
- , which was subsequently subjected to a one-pot desilylation to afford 24. Reduction of both the ester and ketone functionalities in 24, followed by selective protection of the primary alcohol and re-oxidation of the secondary alcohol to ketone, furnished compound 25 in three steps. The ketone in 25 was
- NaOH facilitated a retro-Claisen reaction, yielding the intermediate 106, which subsequently underwent an intramolecular aldol reaction to form the five-membered ring. The resulting carboxylic acid was then esterified with TMSCHN2 to furnish ester 107, which possesses the characteristic tricyclo
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
- activities and serves as a potent modulator of intracellular calcium release channels. In contrast to ryanodol (4), compound 1 possesses a pyrrole-2-carboxylate ester moiety at the C3 position. This ester group can be cleaved via hydrolysis to yield 4. However, the reverse transformation – the synthesis of
- reported the first total synthesis of ryanodine from ryanodol [47] (Scheme 5). Their strategy utilized a novel boronate protecting group to mask the four syn-oriented hydroxy groups. A critical step was the in-situ generation of the pyrrole-2-carboxylate unit from a glycine ester and 1,3-bis(dimethylamino
- effectively resolved a major obstacle in the synthesis of ryanodine (1) and established a versatile approach for introducing diverse C3 ester substituents for future SAR studies [49]. The synthesis commenced from advanced intermediate 71 (from their prior work). Sequential SeO2-mediated oxidation, triflation
Ni-promoted reductive cyclization cascade enables a total synthesis of (+)-aglacin B
Beilstein J. Org. Chem. 2025, 21, 2548–2552, doi:10.3762/bjoc.21.197
- File 1). The generated ester 10 was then converted into the corresponding acyl chloride by saponification and subsequent reaction with pivaloyl chloride. The resulting acyl chloride was then trapped by (S)-4-phenyl-2-oxazolidinone (11) to produce the desired α,β-unsaturated amide 7. Next, the
Isoorotamide-based peptide nucleic acid nucleobases with extended linkers aimed at distal base recognition of adenosine in double helical RNA
Beilstein J. Org. Chem. 2025, 21, 2513–2523, doi:10.3762/bjoc.21.193
- % of the final desired monomer 8 was also isolated in the coupling step, presumably due to hydrolysis of the allyl ester in the iron reduction step. The remaining allyl ester 7 was deallylated via Pd(PPh3)4 to afford the monomer 8 in 51% yield. Db2 Synthesis Db2 was prepared through a convergent
- perform equally well using conventional heating methods. Aniline 10 and carboxylic acid 13 were combined under standard (HBTU) amide coupling conditions to afford benzyl ester 14 in 52% yield. Compound 14 was subsequently debenzylated via hydrogenolysis to afford the target Db2 monomer 15 in 77% yield
- -nitroaniline into benzyl acrylate to afford compound 17 in 57% yield (Scheme 3). Aniline 17 then was subjected to a three-step Boc protection, nitro reduction, and coupling with isoorotic acid derivative 6 that afforded 18 in 39% yield over 3 steps. The benzyl ester was then cleaved under hydrogenolysis
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
- the nucleophilic substitution of the nitro group in 2-nitrobenzonitriles using Na2S in a DMF/water medium, followed by alkylation of the resulting 2-cyanophenylthiolates and subsequent cyclization [31]. However, in our case, the reaction of ester 1 with Na2S in either acetone or a DMF/water mixture
- to be an unsuitable route for nucleophilic substitution of its nitro group. Next, we explored an alternative route using potassium thioacetate (KSAc) as a softer nucleophile. Unexpectedly, the reaction of ester 1 with KSAc in acetone gave a mixture of products other than the desired 3-AcS-substituted
- , necessitates consideration of a reaction mechanism beyond straightforward nucleophilic substitution of the nitro group in ester 1. Although the initial reaction probably involves a nucleophilic attack by the S-nucleophile on the activated thiophene ring, resulting in displacement of the nitro group, the
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
- pentacyclic structure, 2,11-dioxo-A-norolean-12,18(19)-dien-30-oic acid 39, from pharmaceutical 18,19-dehydroglycyrrhetic acid (18,19-dehydro-GLA) 33. Compound 33 was converted to its methyl ester 34 and oxidized by pyridinium dichromate (PDC) in CH2Cl2 to 3-oxo-18,19-dehydro-GLA 35 with a 75% yield. α
- -Ethylformylation of compound 35 and subsequent oxidation of ketoenol 36 with 30% aqueous H2O2 in the presence of a 28% MeONa/MeOH solution resulted in the formation of a diacid, which was then converted into dimethyl ester 37 with a yield of 55%. Refluxing ester 37 with an excess of t-BuOK in benzene gave acid 39
- with a yield of 53% yield. The excess of base (t-BuOK) caused simultaneous decarboxylation and hydrolysis of ester 37, forming the new nortriterpenoid 39 with a pentacyclic ring A (Scheme 7). In the work of Rath et al. [32], a similar method was proposed for the interconversion of cycles in the
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
- characteristics, arising from the ester group and the non-polar hydrocarbon chain, respectively. The nitrone contains a polar functional group (N–O) and two aromatic rings, which serve to generate both polar and dispersion forces. Consequently, these findings indicate that fatty acid methyl esters may possess
Synthetic study toward vibralactone
Beilstein J. Org. Chem. 2025, 21, 2376–2382, doi:10.3762/bjoc.21.182
- , although the corresponding enone product was not isolated. Facing a dead-end, the synthetic route to precursor 14 needed to be revised. From 15, after sodium methoxide-mediated ring opening of lactone, the Fráter–Seebach alkylation [39][40][41] was applied to afford β-hydroxy ester 18. At this stage, the
- the β-lactone was converted into the linear methyl ester 19 to decrease the potential steric hinderance associated with the fused bicyclic skeleton, substrates containing a free hydroxy group or the corresponding TES ether still failed to close the cyclopentene ring. In this scenario, it was necessary
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
- macrocycle occurs along a thread containing fumaramide and succinic amide ester units as recognition sites, with highly fluorescent perylene bisimide and pyrene serving as stoppers [67]. The macrocycle features two pyridine units that, upon protonation, effectively quench the fluorescence of both
Comparative analysis of complanadine A total syntheses
Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178
- lycodine 34 underwent Ir-catalyzed C3–H borylation mainly guided by steric factors to provide boronic ester 35 in 75% yield. With the boronic ester handle at the C3 position, the subsequent Suzuki–Miyaura cross coupling between 35 and 33 occurred smoothly to deliver pseudo-dimer 36, which upon acidic
- used in the Sarpong synthesis was again utilized here to introduce a boronic ester at the C3 position, which was further converted to 3-bromopyridine 55 with CuBr2. With both 54 and 55, Tsukano and co-workers employed a remarkable pyridine N-oxide directed C–H arylation method developed by Fagnou et al
- skeleton and the newly developed C–H borylation to install a boronic ester handle at the desired position for a Suzuki–Miyaura cross coupling to build the C2–C3’ linkage which was hidden in bis(trimethylsilyl)butadiyne (20) of the Siegel synthesis. Both the groups of Tsukano and Dai utilized a pyridine N
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
- by the Yang group [22]. Installation of the hydroxymethyl group in 4 was achieved through sequential formylation and reduction. Compound 4 then underwent a one-pot, substrate-controlled diastereoselective Johnson−Claisen rearrangement/acetylation to install ester 5. Treating 5 with m-CPBA (meta
- . This transformation proceeded via sequential regio- and stereoselective Norrish−Yang annulation, followed by intramolecular lactonization mediated by 12a. Notably, when the ethyl ester in 12 was replaced with a methyl group to form 14 with R = Et (Scheme 3), photoreaction of 14 led to 15 in 95% yield
- drives this migration, due to the highly sterically congested environment – exacerbated by the 1,3-strain between the methyl groups at C10 and C14. The observed 1,2-methyl migration also underscores the critical role of the preinstalled ester group in 12: it suppresses potential methyl migration
Other Beilstein-Institut Open Science Activities
