C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• level of oxygen content in biomass, small molecules arising from biomass often possess a carbonyl group. This is why biobased platform molecules possessing a carbonyl group, either under the form of an aldehyde, a ketone, an acid or an ester, play a dominant role in biobased chemistry. This review aims

• , and illustrating their high-value conversion methods towards fine chemicals. Review C2 biobased carbonyl platforms Glycolaldehyde Developing accesses from biomass to structures such as glycolic acid (GA) and glycolaldehyde (GCA) with high atomic economy is challenging. Hu et al. reported a new route

• –Crafts alkylation products were then converted into an intermediate tryptaldehyde that underwent intramolecular olefination to form the targeted product [34]. Glycolic acid (GA) The growing impact of fossil fuel consumption has heightened the need for advancing renewable energy technologies. One

The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• on the reported method for asymmetric transfer hydrogenation of commercially available cyclopentadione 62 [54], the authors adapted an efficient method for the desymmetric enantioselective reduction of 62 using commercially available (R,R)-Ts-DENEB (63) as the catalyst and formic acid as the hydrogen

• -catalyzed intermolecular Diels–Alder reaction of 106 with methacrolein 107 afforded the common intermediate 108 in high yield. Sequential Grignard reagent addition and acid-promoted ethoxy elimination provided the separable planar diene 109 (dr = 1:1), which underwent a Mn-catalyzed HAT hydrogenation to

• give (15R)-110 and (15S)-110 in 65% and 54% yield, respectively. Subsequently, ten functional group manipulations of the diastereomeric mixture 110 produced ketoester 111. Finally, the introduction of conjugated double bond in 111 followed by hydrolysis of the methyl ester to carboxylic acid and DCC

Multicomponent reactions IV

• Thomas J. J. Müller and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2082–2084, doi:10.3762/bjoc.21.163

• between an aldehyde, an amine, a carboxylic acid, and an isonitrile in 1959 [8], which marked the beginning of modern MCR chemistry, continues to attract undiminished attention. It has since been applied in manifold ways, from breathtaking reaction sequences and post-Ugi transformations to the generation

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

• Jin-Fang Lü,
• Jiang-Feng Wu,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162

• compound 14, an intermediate in our synthesis of (–)-isochaetominine A (4) [63]. Indeed, EDCI/HOBt-mediated lactamization of 14 derived amino acid (not shown) via debenzylation increased the yield of (–)-isochaetominine A (4) from 75% to 91% (Scheme 1). Thus, overall yield of the total synthesis of

• (–)-isochaetominine A (4) increased to 30.8% over five steps. Similarly, EDCI/HOBt-mediated lactamization of amino acid (not shown) derived from 15 [63] via debenzylation produced the known (–)-2,3,14-tris-epi-isochaetominine C (16) with a significantly increased 92% yield. The epoxidation-triggered stereodivergent

• , anthranilic acid, and ᴅ-tryptophan”. Such speculation regarding the absolute configurations is clearly not convincing. Moreover, neither optical rotation data nor melting point (both 12 and 13 were isolated as white powder) have been reported by Liu et al. [32]. Additionally, the solvents used for measuring

Discovery of cytotoxic indolo[1,2-c]quinazoline derivatives through scaffold-based design

• Daniil V. Khabarov,
• Valeria A. Litvinova,
• Lyubov G. Dezhenkova,
• Dmitry N. Kaluzhny,
• Alexander S. Tikhomirov and
• Andrey E. Shchekotikhin

Beilstein J. Org. Chem. 2025, 21, 2062–2071, doi:10.3762/bjoc.21.161

• introduce the carboxylic acid group a sequence of formylation/oxidation reactions was used. Vilsmeier–Haack reaction of 1 afforded 6-oxoindolo[1,2-c]quinazoline-12-carbaldehyde (2) (Scheme 1). All attempts to oxidize the aldehyde group of 2 to the corresponding carboxylic acid were hampered by the oxidative

• sensitivity of the indole moiety, resulting in poor selectivity and formation of complex product mixtures. In particular, Jones oxidation of 2 gave the corresponding 6-oxoindolo[1,2-c]quinazoline-12-carboxylic acid (3) in a low yield (Scheme 1) making it necessary to look another synthetic pathway. Of

• (5) (Scheme 1), a structural analogue of the biologically active alkaloid tryptanthrin (Figure 1). An alternative scheme to indolo[1,2-c]quinazoline-12-carboxylic acid (3) was based on initial acylation followed by a haloform reaction. Refluxing compound 1 with trifluoroacetic anhydride (TFAA) in

Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• symbiotic natural products. The proposal lacks strong evidences, no matter it is scientifically reasonable or not. The bioinspired synthetic would provide evidences to support such a plausible biogenetic pathway through chemical transformations under simple biomimetic reaction conditions like acid, base, or

• aldehyde 3. This linear aldehyde would be activated by an acid to trigger a key Prins cyclization with the trisubstituted olefin through reaction model 3 and generate a putative tertiary carbocation to be trapped by the chiral alcohol, providing bicycle 4 stereoselectively. Finally, the last olefin would

• with an acid and base-promoted saponification inversed the C12 alcohol stereochemistry, which ultimately provided (12R)-hydroxymonocerin. Total synthesis and bioinspired skeletal diversification of (12-MeO)-tabertinggine In 2013, Kam and co-workers reported the discovery of two novel indole alkaloids

Switchable pathways of multicomponent heterocyclizations of 5-amino-1,2,4-triazoles with salicylaldehydes and pyruvic acid

• Yana I. Sakhno,
• Oleksander V. Buravov,
• Kostyantyn Yu. Yurkov,
• Anastasia Yu. Andryushchenko,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2030–2035, doi:10.3762/bjoc.21.158

• -triazoles, pyruvic acid, and salicylaldehydes were studied under different conditions. Upon conventional heating, benzotriazolooxadiazocine-5-carboxylic acids were formed in the three-component reactions as single reaction products. Upon ultrasonic activation or mechanical stirring at room temperature, the

• also was described in several other publications [13][14][15]. On the other hand, three-component reactions of aminoazoles, salicylaldehyde, and esters (or amides) of acetoacetic acid with isolation of other types of heterocylic compounds were described in some papers [16][17]. Our early works were

• devoted to the study of the reactions of aminoazoles, pyruvic acid and its derivatives with salicylaldehydes and it was found that depending on the conditions (reaction time, temperature, and method of process activation, in particular ultrasound and microwave irradiation), different types of heterocycles

α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

• Vladyslav O. Honcharov,
• Yana I. Sakhno,
• Olena H. Shvets,
• Vyacheslav E. Saraev,
• Svitlana V. Shishkina,
• Tetyana V. Shcherbakova and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157

• library of bis- and tetraamides was synthesized by the Ugi reaction with α-ketoglutaric acid, tert-butyl isocyanide, aromatic aldehydes, and aromatic amines. When o-azidoanilines were used, azidated peptidomimetics were obtained, the post-cyclization of which by the aza-Wittig reaction yielded a series of

• substituted 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoic acids containing a pharmacophore quinoxalinone moiety. The tandem Ugi/aza-Wittig combination was also carried out in a one-pot procedure without isolation of the intermediate. Keywords: α-ketoglutaric acid; aza-Wittig reaction; multicomponent reaction

• nitrogen-containing heterocyclic compounds using various modifications of this sequence [32][33][34][35][36]. Among others, Yan et al. [31] described a facile way to quinoxalinone derivatives using an Ugi/Staudinger/aza-Wittig tandem combination with pyruvic acid or phenylglyoxylic acid. Quinoxalinones are

Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis

• Rasma Kroņkalne,
• Rūdolfs Beļaunieks,
• Armands Sebris,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154

• chemoselectivity towards diene formation (Table 1, entries 15 and 16). In accordance with the proposed reaction mechanism (Scheme 2), an equimolar amount of protons is generated in the reaction, which would likely induce the formation of additional side-products either by protodecupration [27] or the acid

• acid, its sodium salt or the silylated carboxylic acid), the arylation reaction of aliphatic chain-containing propargylsilane 7b (standard conditions; see Scheme 3) only resulted in the arylation of the oxygen nucleophile itself. Next, we proceeded to expand the substrate scope by exploring other

• internal nucleophiles (Scheme 4), that could be used instead of the alcohol. The carboxylic acid-containing silane 7 (R = COOH), which was obtained by stepwise oxidation of the alcohol 7d, failed to give the desired lactone 8t product due to O-arylation of the carboxylic acid, leading to phenyl alkyl ester

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• suitably electrophilic substrate at the carboxylic acid oxidation level provides an acylazolium species B, which typically reacts directly with nucleophiles or may first be transformed into the corresponding enolate derivative. Regardless of the individual pathway, NHC-catalyzed reactions of this type

• 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

• manifold with carboxylic acid derivatives, numerous coupling processes affording ketone products have been developed. Since the initial report from Scheidt and co-workers using 4-alkyl-substituted Hantzsch esters as coupling partners [31][32][33][34][35][36], several alkyl radical sources have been

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

• Miao Xiao,
• Liuyang Pu,
• Qiaoli Shang,
• Lei Zhu and
• Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

• reaction at 50 °C for 36 h, and extensive decomposition of the starting material β-keto ester 15 occurred (Table 1, entry 1). Solvent screening of EtOH [26], acetic acid [26], and hexafluoroisopropanol (HFIP) [27] demonstrated that HFIP afforded optimal results, delivering cyclopentanone 14 in 63% yield as

• 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

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• . Lipases commonly share typical sequences of α-helices and β-strands and possess a catalytic triad consisting of serine (Ser), histidine (His), and aspartate (Asp) or glutamate (Glu). These three amino residues function as a nucleophile-base–acid catalytic system to facilitate esterification, and the

• Lewis acid-mediated semi-pinacol rearrangement, this work involved a CRL-catalyzed desymmetrization of prochiral diol 51 (prepared from aldehyde 50 in four steps), providing monoester 53 in 57% yield with 83% ee. Notably, 1-ethoxyvinyl 2-furoate (52) was selected as the acyl donor in this step to

• functional group manipulations, alcohol 103 was subjected to enzymatic oxidative kinetic resolution with the bacterium Gluconobacter oxydans, producing alcohol 104 and acid 105. The alcohol 104 with the desired C9 stereocenter was then converted into fragment 106 in nine steps, while acid 105 was recycled to

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• ][3]. Established sets of reactive probes are typically armed with electrophilic warheads that have the potential to target nucleophilic amino acid side chains. Most reactive probe sets bear cysteine-directed warheads [3][4][5][6][7], although sets have also been designed to target a wider range of

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• oxidation of amide and other amino acid side‐chain fragments. By tracking changes in this oxidation signal upon addition of an alkylating agent, we can infer whether the agent has effectively reacted with (and thus structurally altered) the protein. As illustrated by the black trace in the LSV plot, pure

• . When these agents alkylate the HSA amino acid residues (particularly reactive sites like lysine, cysteine, serine NH2, SH, OH-side chains, and possibly other nucleophilic groups), the resulting covalent modification can disrupt the electroactive centers responsible for the protein’s oxidation peaks

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• for different N-benzyl benzaldimines in moderate to good yields. In 1991, Shono’s research group described the electroreductive intramolecular coupling of aromatic diimines, carried out in DMF in the presence of methanesulfonic acid in a divided cell equipped with a lead cathode, a carbon rod anode

• reaction and a screening of reaction parameters such as solvents, electrodes materials, electrolytes, total charges, and concentrations of the reaction mixture was performed. All optimization studies were carried out using 0.5 mmol of 1a in the presence of methanesulfonic acid in an undivided cell (5 mL

• co-workers [44], the presence of a strong protic acid, such as methanesulfonic acid, MsOH, is essential to promote the intramolecular coupling. A control experiment revealed that when the electroreduction of 1a was performed in the absence of MsOH (Table 1, entry 3), no formation of the desired

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• the presence of a Lewis acid. The use of BF3·OEt2 gave a low yield of the desired alcohol 2 [29]. This was improved slightly with Sc(OTf)3 as the Lewis acid, which could be used substoichiometrically [30]. The alcohol 2 was converted to the tosylate 3 and subsequent ozonolysis gave the aldehyde 4. The

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• with the more recently introduced inherent chirality. As one of the most prominent chiral organocatalysts, chiral phosphoric acid (CPA) catalysis has proven highly effective in synthesizing centrally and axially chiral molecules. However, its potential in the asymmetric construction of other types of

• within this domain. Keywords: asymmetric catalysis; chiral phosphoric acid; helical chirality; inherent chirality; planar chirality; Introduction Since the seminal works by Akiyama [1] and Terada [2] et al. in 2004 demonstrated the application of BINOL-derived chiral phosphoric acids (CPAs) in

• catalytic sites. The OH group on the phosphorus atom functions as a Brønsted acid site, while P=O serves as a Lewis base site, which enables the simultaneous activation of both nucleophiles and electrophiles in one reaction (Figure 1). The chiral properties of the catalysts are derived from the chiral

Systematic pore lipophilization to enhance the efficiency of an amine-based MOF catalyst in the solvent-free Knoevenagel reaction

• Pricilla Matseketsa,
• Margret Kumbirayi Ruwimbo Pagare and
• Tendai Gadzikwa

Beilstein J. Org. Chem. 2025, 21, 1854–1863, doi:10.3762/bjoc.21.144

• efficiency. Keywords: metal-organic frameworks; post-synthesis modification; supramolecular catalysis; Introduction Most enzymatic reactions take place in multifunctional cavities in which multiple amino acid residues work cooperatively to orient and activate reactants [1][2][3]. These residues may also

• enhance covalent and/or acid–base catalysis via any combination of non-covalent interactions (hydrogen bonding, π–π stacking, lipophilic interactions, etc) [4][5][6]. Inspired by enzymes, Nature's most efficient catalysts, chemists have long endeavored to synthesize catalytic materials in which multiple

• by increasing the binding affinity for the lipophilic reactants and by decreasing the energy required to desolvate acid/base amino acid catalysts [34][35]. Lipophilicity has also been found to be beneficial in condensation reactions as the removed water molecules are repelled by the hydrophobic

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

• and subsequent reduction of 45 (if substrates 43 and 44 contain a NO2 group, this will also be reduced, Scheme 13A) [54], or by Wittig reaction and reduction of the isomeric mixture of alkenes 48 (Scheme 13B) [57]. Oxidation of 49 with oxone [58] or m-chloroperbenzoic acid [54] yields 35. Wittig

• methods for N-arylation depending on the aryl type: electron-rich and electron-neutral substituents are introduced via Chan–Lam coupling with an arylboronic acid, electron-poor aromatics via Cu(I)-catalysed cross-coupling with aryliodonium salts, and monosubstitution is achieved via Ullman–Goldberg

• 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

Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp²)–C(sp²) bond scission of styrenes

• Prafull A. Jagtap,
• Manish M. Petkar,
• Vaishnavi R. Sawant and
• Bhalchandra M. Bhanage

Beilstein J. Org. Chem. 2025, 21, 1799–1807, doi:10.3762/bjoc.21.142

• [53]. In this work, the authors used a stoichiometric amount of Zn(OTf)3 as a Lewis acid catalyst and air as the oxidant for the reaction. Jana and colleagues demonstrated an atom-efficient pseudo-three-component C–H annulation reaction catalyzed by Yb and Cu, which involved nitrosoarenes and styrene

• , the present C–H annulation reaction of aniline (1a) with styrene (2a) was initially carried out in TFE (trifluoroethanol) as solvent in the presence of 25 mol % FeCl3·6H2O as a catalyst and 1.5 equiv of TFA (trifluoroacetic acid) as an additive (Table 1, entry 1). For this reaction, 12% of 2,4

• cleavage as well as inadequate Lewis acid activation of N-methylaniline (1a′), which hinders its further cyclization into the final product 3a′. The reaction, when conducted in the absence of a catalyst, failed to proceed, thereby highlighting the crucial role of catalytic activation in facilitating the

[3 + 2] Cycloaddition of thioformylium methylide with various arylidene-azolones in the synthesis of 7-thia-3-azaspiro[4.4]nonan-4-ones

• Daniil I. Rudik,
• Irina V. Tiushina,
• Anatoly I. Sokolov,
• Alexander Yu. Smirnov,
• Alexander R. Romanenko,
• Alexander A. Korlyukov,
• Andrey A. Mikhaylov and
• Mikhail S. Baranov

Beilstein J. Org. Chem. 2025, 21, 1791–1798, doi:10.3762/bjoc.21.141

• 1–5e with para-methoxy group in the aromatic ring (Table 1, Supporting Information File 1, part 2). Typically thioformylium methylide is generated from compound I by action of CsF or TBAF [16][23][24]. We also tested other fluorides and trifluoroacetic acid (Supporting Information File 1, part 2

Synthesis of chiral cyclohexane-linked bisimidazolines

• Changmeng Xi,
• Qingshan Sun and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140

• bisimidazolines are efficient chiral ligands in metal-catalyzed asymmetric organic transformations. Chiral cyclohexane-linked bisimidazolines were prepared from optically active cyclohexane-1,2-dicarboxylic acid and 1,2-diphenylethane-1,2-diamines via the monosulfonylation of 1,2-diphenylethane-1,2-diamines

• , condensation of N-sulfonylated 1,2-diphenylethane-1,2-diamines and cyclohexane-1,2-dicarboxylic acid, and the final cyclization with the in situ generated Hendrickson reagent. Keywords: bisimidazoline; cyclohexane; cyclohexane-1,2-dicarboxylic acid; 1,2-diphenylethane-1,2-diamine; Introduction Chiral

• bisimidazoline (PyBim) ligands derived from pyridine-2,6-dicarbonitrile or pyridine-2,6-dicarboxylic acid and vicinal diamines, as analogues of pyridine-linked bisoxazoline (PyBOX) ligands [16][17]. They exhibited excellent performance in metal-catalyzed asymmetric organic reactions. Chiral rigid backbone-linked

Research progress on calixarene/pillararene-based controlled drug release systems

• Liu-Huan Yi,
• Jian Qin,
• Si-Ran Lu,
• Liu-Pan Yang,
• Li-Li Wang and
• Huan Yao

Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139

• solubility, this can be improved through derivatization. Water-soluble calixarene derivatives can be obtained through functional modifications, including the introduction of sulfonic acid, amine, and carboxylic acid groups [57][58][59]. These water soluble macrocycle derivatives can be used to increase the

• a hot topic [75]. PAs can be prepared via the Friedel–Crafts condensation, which involves combining 1,4-dimethoxybenzene with paraformaldehyde in the presence of a Lewis acid. The central axis of these aromatic hydrocarbon molecules possesses n fold rotational symmetry [76]. PAs possess highly

• ]arene (WP7) by adding 14 anionic carboxylic acid groups to both sides [102]. They explored the pH-dependent complexation of WP7 with paraquat derivative G1 in water. The host WP7 and guest G1 form a 1:1 pseudorotaxane, with an association constant of (2.96 ± 0.31) × 105 M−1. Furthermore, they leveraged

Preparation of a furfural-derived enantioenriched vinyloxazoline building block and exploring its reactivity

• Madara Darzina,
• Anna Lielpetere and
• Aigars Jirgensons

Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136

• oxidation in methanol in batch electrolysis conditions, providing unsaturated esters S-3d and R-3d, respectively (Scheme 2). The previously used one-reactor two-step conditions were found to be productive for the electrosynthesis of S-3d, requiring the addition of acetic acid for the intermediate spiroketal

• reaction, and we found that acetic acid served well for this purpose (Table 1, entry 4). Using the reaction conditions with acetic acid as additive, the reaction could be performed also in a 0.5 g scale for the synthesis of both ester enantiomers S-3d and R-3d (Table 1, entries 5 and 6). In the absence of

• acetic acid or HFIP the electrochemical oxidation also provided the desired product 3d, although in reduced yield (Table 1, entry 7). An increased amount of acetic acid (1 mL or ≈ 18 equiv) also reduced the yield (Table 1, entry 8). The attempt to use LiOAc as electrolyte instead of LiClO4 was not

Convenient alternative synthesis of the Malassezia-derived virulence factor malassezione and related compounds

• Karu Ramesh and
• Stephen L. Bearne

Beilstein J. Org. Chem. 2025, 21, 1730–1736, doi:10.3762/bjoc.21.135

• receptor agonist and potential glucokinase activator, we developed a convenient synthetic route from commercially available indole-3-acetic acid. Treatment of the N-Boc-protected indole-3-acetic acid with N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide (EDC) in the presence of DMAP generates the N,N′-Boc

• ]. Herein, we report an alternative synthesis from commercially available indole acetic acid, and demonstrate that the approach can be extended to related compounds. Results and Discussion Previously, malassezione had either been (i) isolated from cultures of M. furfur grown on ʟ-tryptophan as the sole

• nitrogen source followed by thin-layer chromatography and reversed-phase (RP)-HPLC to isolate and purify the compound from a complex mixture of indole alkaloids [11], (ii) prepared by aerobic incubation of indole-3-pyruvic acid at pH 7.4, 37 °C for 24 h followed by isolation and purification using RP-HPLC