Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• crystal XRD analysis confirmed the presence of the expected products and the stereochemistry of the newly created olefinic compound as being Z, as expected. Compound 3n crystallizes in the monoclinic crystal system with four molecules in the asymmetric unit whereas 4n crystallizes in the triclinic crystal

Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies

• Zhi-Qi Cao,
• Jin-Bao Qiao and
• Yu-Ming Zhao

Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198

• carbonyl, a silyl transform, and oxidation of the C2 secondary hydroxy group afforded intermediate 54. This sequence successfully installed the C3 hydroxy group with the requisite stereochemistry for 3-epi-ryanodol (5). Subsequent introduction of an isopropyl group at C2 and global deprotection yielded the

• C10 stereochemistry, thereby completing the total synthesis of anhydroryanodol (10). By applying established strategies developed by Deslongchamps and Reisman to this intermediate, they enabled the formal total syntheses of ryanodol (4) and ryanodine (1). Summary and Outlook Ryania diterpenoid natural

Rapid access to the core of malayamycin A by intramolecular dipolar cycloaddition

• Yilin Liu,
• Yuchen Yang,
• Chen Yang,
• Sha-Hua Huang,
• Jian Jin and
• Ran Hong

Beilstein J. Org. Chem. 2025, 21, 2542–2547, doi:10.3762/bjoc.21.196

• stereochemistry of substituents, as well as the heterocyclic anomeric unit. Uncertainty regarding the mode of action, along with inadequate synthetic approaches toward a lead compound, remains elusive. The well-established synthetic route reported by Hanessian and co-workers began with ᴅ-ribonolactone which bears

• undesired stereochemistry at C3 due to a possible chair-like transition state like 10a (Scheme 2B). This phenomenon is consistent with the observations from previous syntheses [31][35][36]. We anticipated that late-stage epimerization might invert the configuration once the acyl group is revealed at the C2

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• regioselectivity (>99:1) and complete preservation of the stereochemistry at both quaternary carbon centers (Scheme 17). Through a series of synthetic transformations, the target products (+)-cuparene (91) and (+)-tochuinylacetate (92) were synthesized from acids 96a and 96b with high regioselectivity. In [53

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• difference between TS30b (ΔΔG‡ = 0.3 kcal/mol) and TS30a (ΔΔG‡ = 0), resulting in the formation of 31 as a 1:1 mixture of regioisomers (Scheme 5c). In this work, to address unsatisfactory C4 stereochemistry in initial synthesis, the authors introduced a double bond to alter substrate conformation, enabling

Enantioselective radical chemistry: a bright future ahead

• Anna C. Renner,
• Sagar S. Thorat,
• Hariharaputhiran Subramanian and
• Mukund P. Sibi

Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174

• synthesis. Strategies for asymmetric radical reactions Stereoselectivity in radical reactions can be challenging to control. Many radicals are highly reactive, and radicals moreover have typically low inversion barriers, resulting in no permanent chirality at the radical center. Stereochemistry in radical

• occurred in an anti fashion. Products were obtained with up to 97% ee via catalysis by complexes of magnesium or copper(II) with ligand L1. The absolute stereochemistry of the product could be controlled by a simple change from copper(II) to magnesium Lewis acids while using the same chiral ligand, thus

A chiral LC–MS strategy for stereochemical assignment of natural products sharing a 3-methylpent-4-en-2-ol moiety in their terminal structures

• Rei Suo,
• Raku Irie,
• Hinako Nakayama,
• Yuta Ishimaru,
• Yuya Akama,
• Masato Oikawa and
• Shiro Itoi

Beilstein J. Org. Chem. 2025, 21, 2243–2249, doi:10.3762/bjoc.21.171

• terminal position of various polyketide natural products such as a series of azaphilones including chaetomugilins [14], chaetoviridins [14][15], and some other α-pyrone polyketides [16][17][18] (Figure 1). Among the available strategies for elucidating the stereochemistry of MPO, X-ray crystallographic

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

• structures of aspera chaetominines A and B and revision of stereochemistry of aspera chaetominine B Several years after we have had accomplished the abovementioned investigations, Liu and co-workers reported the isolation and structural elucidation of two new alkaloids, aspera chaetominines A (12) and B (13

• chaetominine A (12) and monocyclization product 26 in 31% and 45% yield, respectively. The spectral (1H and 13C NMR) data of our synthetic compound are different from those reported for the natural aspera chaetominine A, suggesting that the originally proposed stereochemistry for aspera chaetominine A (12) was

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

• 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

Understanding the origin of stereoselectivity in the photochemical denitrogenation of 2,3-diazabicyclo[2.2.1]heptene and its derivatives with non-adiabatic molecular dynamics

• Leticia A. Gomes and
• Steven A. Lopez

Beilstein J. Org. Chem. 2025, 21, 2007–2020, doi:10.3762/bjoc.21.156

• effects. Previous studies, summarized in Scheme 3, predicted that a diazenyl diradical (az-DZ) with one broken C–N bond would retain the stereochemistry of the reactant, leading directly to the formation of retained housane. However, this pathway was not observed when dynamical effects were included in

• . At the hopping point (274 fs), both θ₁ and θ₂ are significantly increased (149° and 153°, respectively). Here, all carbons of the methylene bridge are located above the molecular plane, indicating complete inversion of stereochemistry. Using kernel density estimation [101], we found that partially

• dynamically concerted but asynchronous denitrogenation reaction, characterized by breaking one σCN bond in the S1 state and the second σCN bond in the S0 state. After the first σCN bond breaks, the stereochemistry of the carbon bonded to N2 begins to invert, suggesting that dynamic effects promote this

Measuring the stereogenic remoteness in non-central chirality: a stereocontrol connectivity index for asymmetric reactions

• Ivan Keng Wee On,
• Yu Kun Choo,
• Sambhav Baid and
• Ye Zhu

Beilstein J. Org. Chem. 2025, 21, 1995–2006, doi:10.3762/bjoc.21.155

• stereochemical differentiation should at least be traced to the two pilot atoms that are directly attached, but not within the stereogenic plane – similar to the assignment of stereochemistry for cyclophanes. This way, the asymmetric Pd-catalyzed coupling [19][20] would be assigned as [30] (Scheme 5B and 5C). On

• . Nonetheless, the stereocontrol connectivity index can provide information on the stereochemical properties of reactions, beyond the existing binary (yes/no) stereochemistry classifications in widely used chemical databases such as CAS SciFinder and Reaxys. This exercise applies not only to existing asymmetric

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

• -triisopropylbenzenethiol (TRIPSH) through a hydrogen atom transfer (HAT) process to afford intermediate 30 [39], which then cyclized to yield product 21. To install the allyl group at C8 with the desired stereochemistry, we treated compound 21 with p-TSA in EtOH at room temperature, and ketal 31 was obtained in 87% yield

• stereochemistry at C9. Therefore, alcohol 32 was subjected to a one-pot Mitsunobu reaction, hydrolyzation, and spirolactonization to give the corresponding alcohol 26 with inversed configuration at C9. Finally, terminal alkene 26 was transformed by Dai’s Ru-catalyzed Z-selective cross-metathesis with 33 [9][40

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

• of an oxime, itself prepared in situ from an aldehyde. The stereochemistry of one of the spirooxindoles was determined by single crystal X-ray diffraction studies via crystallisation using encapsulated nanodroplet crystallisation (ENaCt) protocols. The chemistry involves cascade or tandem

• condensation, cyclisation, and cycloaddition as an efficient strategy for the rapid formation of complex spirocyclic products that could have value for the formation of novel, bioactive oxindoles. Keywords: cascade; cycloaddition; oxindole; spirocycle; stereochemistry; Introduction The Alstonia alkaloids are

• rate of evaporation from a nanolitre solution of analyte encased within oil [33], suitable single crystals were obtained. The X-ray analysis allowed the determination of the relative stereochemistry, as shown in Figure 2. Compound 5a crystallised as a racemic mixture in the space group P21/c. The major

[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

• thiohydantoin derivatives, since the initial compounds 2 had a predominant Z-configuration. At the same time, for cases 1, 3 and 4, both a synchronous and stepwise mechanism are possible. The discovered stereochemistry of the reaction correlates well with the previously obtained data, when the most

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

• Unless otherwise stated, all BINOL derivatives were used as the (S)-enantiomers and the stereochemistry will not be mentioned further. Synthesis of macrocycles featuring one BINOL unit We first investigated the synthesis of crown ether-type macrocycles M1 which feature a single BINOL unit. Our previous

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• applications. The assembly of nonreducing 1,1′-linked disaccharides presents greater challenges than conventional chemical glycosylation due to the need for simultaneous control of stereochemistry at two anomeric centers. The structural complexity of natural biomolecules entailing 1,1′-disaccharides, which

• . The glycosylation reaction for forming nonreducing (1,1'-linked) disaccharides is inherently more complex than traditional glycosylation protocols, due to the importance of controlling the stereochemistry at two anomeric centers simultaneously. Consequently, the 1,1'-glycosylation reaction

Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides

• Tsun-Yi Chiang,
• Mei-Huei Lin,
• Chun-Wei Chang,
• Jinq-Chyi Lee and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2025, 21, 1671–1677, doi:10.3762/bjoc.21.131

• biomolecules in organisms. However, the R/S stereochemistry of pyruvate ketal is difficult to control through chemical methods. In this study, the acid-labile pyruvate ketal linked to the 4- and 6-positions of galactose was cautiously constructed, and the X-ray analysis of the R-configured product was

• modifications of bacterial polysaccharides, and the interaction of 4,6-O-pyruvylated pyranoses with lectins depends on the stereochemistry of the pyruvate ketal. Moreover, this chemical modification is crucial, as the distinct R or S diastereochemistry at the ketal center directly influences its biological

• define the stereochemistry of pyruvate ketals as either R- or S-configurations. Typically, S-configuration exhibits 13C NMR shifts between δ 17–24 ppm and 1H NMR shifts δ 1.60–2.10 ppm, whereas the R-configuration shows 13C shifts downfield at δ 24-27 ppm and 1H shifts at δ 1.40–2.00 ppm [19][20][21][22

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• ] and pyrenylenes [17][18] were reported to adopt unique chiral arrangements depending on their stereochemistry. Helical motifs such as carbo[4]helicene and oxa[5]helicene were incorporated into cyclic structures, giving rise to cyclic carbo[4]helicenylene A and cyclic oxa[5]helicenylene-biphenylene B

N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B

• Joy E. Rajakulendran,
• Emmanuel Tope Oluwabusola,
• Michela Cerone,
• Terry K. Smith,
• Olusoji O. Adebisi,
• Adefolalu Adedotun,
• Gagan Preet,
• Sylvia Soldatou,
• Hai Deng,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103

• H-11 to C-10 (δC 173.5), H3-12 to C-9 (δC 128.1) and C-11 (δC 133.9). The relative stereochemistry of the double bond of the dehydrobutyrine moiety was established as Z based on a medium NOE correlation observed between the amide proton, H-8 (δH 9.82) and the methyl protons, H3-12 (see Figure 2 and

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

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

• the correct stereochemistry of the newly formed three stereocenters. Additionally, replacing cesium carbonate with triethylamine proved crucial for achieving efficient asymmetric hydrogenation in this case. Subsequently, the carboxylic acid group of 57 was reduced with LiAlH4 in THF to produce primary

• stereochemistry (Scheme 11). A further two-carbon homologation of compound 76 through an oxidation and Wittig olefination sequence yielded unsaturated ester 77 in 92% yield. The ester group in 77 was reduced using DIBAL-H, achieving a 95% yield. Sharpless epoxidation of alcohol 78 was then performed using (−)-DET

• stereocenter, significantly reducing overall efficiency. To overcome this challenge, Laschat’s approach leveraged a chiral pool building block – methyl-branched preen gland wax ester – as the starting material. This ester already contained three methyl groups pre-installed with the stereochemistry necessary

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• . Optimization studies identified the tetraphenyl-substituted PyBox ligand L1 as particularly effective in controlling the stereochemistry of the polycyclization, yielding high enantioselectivity for most substrates. As illustrated in Scheme 5, tertiary enamides with a tethered electron-rich arene could undergo

Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes

• Shyam Sathyamoorthi,
• Appasaheb K. Nirpal,
• Dnyaneshwar A. Gorve and
• Steven P. Kelley

Beilstein J. Org. Chem. 2025, 21, 947–954, doi:10.3762/bjoc.21.78

• diacetate was necessary for product formation (Table 3, products 20 and 25–28). X-ray crystallographic analysis of 20 (CCDC 2391529) allowed us to unambiguously determine its identity and relative stereochemistry, and we have assigned other products by analogy. A variety of carbamate substrates were

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• a dihedral angle of 49.86(10) 86.22(11)° with the phenyl rings C6–C11 and C18–C23, respectively. The angle between both phenyl rings is 70.76(11)°. The stereochemistry around the double bond is Z, allowing an intramolecular N–H···O hydrogen bond between one of the carbonyl oxygen atoms and the amino

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• , conformations in which the two C–F bonds are aligned gauche will be favoured in water due to their high molecular dipole moment. A final layer of complexity is afforded by the stereochemistry of the 1,2-difluoroalkane motif: the various conformational factors described above will aggregate differently depending

• upon whether the 1,2-difluoro stereochemistry is threo or erythro. For example, the diastereoisomeric difluorinated stearic acids 14 and 15 (Figure 3) are found to have very different physical properties [28]. When deposited into a monolayer above a water phase, the threo-isomer 14 occupies a small

• emerges. The 1,3-C–F bonds tend to avoid a parallel alignment, due to dipolar repulsion (III, Figure 3) [30][31][32]. This phenomenon can be harnessed to control molecular conformations in a predictable way, and once again the stereochemistry is important. For example, compare the natural product