Kinetic resolution of racemic planar-chiral vinylcymantrenes by molybdenum-catalyzed asymmetric metathesis dimerization

• Haruna Imazu,
• Hitoshi Izu,
• Yasuhiro Ohki and
• Masamichi Ogasawara

Beilstein J. Org. Chem. 2026, 22, 568–574, doi:10.3762/bjoc.22.42

• Science Institute, Tokushima University, Tokushima 770-8501, Japan 10.3762/bjoc.22.42 Abstract Highly diastereo- and enantioselective kinetic resolution (KR) of a series of racemic planar-chiral 1-R-2-vinylcymantrenes (rac-1; R = Br, Me, I) was realized by an asymmetric metathesis dimerization (AMD

• chiral-2a/meso-2a = 96:4 molar ratio, and the selectivity factor (krel) was calculated to be 754 based on a second-order equation. In all the three substrates examined, the dimerized products, chiral-2, were obtained in >98% ee thanks to the outstanding enantioselectivity. Keywords: cymantrene; kinetic

• the excellent tolerance of the Mo-/Ru-metathesis catalysts toward the organometallic substrates. The olefin metathesis protocols could be extended to the asymmetric synthesis of diverse planar-chiral transition metal complexes either by the kinetic resolution of the racemic substrates [14][15][16] or

Get a better glimpse on sequential photoreactions of trisnorbornadienes with ¹⁹F NMR spectroscopy

• Julian Felix Maria Hebborn,
• Ben Eric Merten,
• Thomas Paululat and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 527–534, doi:10.3762/bjoc.22.38

• and 2f1,2 decreased steadily, while the content of the trisquadricyclane 2f0,3 increased (Figure 3). This proposed consecutive, stepwise photoreaction was supported by theoretical analysis which showed a consistent fitting of the experimental data to the proposed kinetic model (see Supporting

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• 119. The addition of propargyl bromide led to racemic 120. By the use of a flow setup involving a column packed with Amano lipase, an enzyme from the bacterium Pseudomonas fluorescens, a kinetic resolution of 120 was performed leading to the continuous production of acetate 121 and free alcohol 122

• ketophosphonate 169 using MePO(OMe)2 and n-BuLi. Notably, building block 171 used herein can be synthesized from 170 within 6 steps including a kinetic resolution with Amano lipase PS-800. [94] Another fragment, 181, was synthesized from alcohols 173 and 174, which were perpared from tri-O-acetyl-ᴅ-glucal and (S

• . Hydrolytic kinetic resolution of 209 afforded enantioenriched epoxide (S)-209, which was opened regioselectively with lithium acetylide. The allylation and [3 + 2]-cycloaddition with tosyl azide led to 212. Treatment with Rh2(OAc)4 induced a [2,3]-Wittig rearrangement and subsequent hydrolysis afforded 213

Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• independently and that their activities and modulation by inhibitors and activators are closely coupled. Both enzymes exist in at least two distinguishable states that differ in their kinetic properties, consistent with the two distinct structural states of the complex observed in the cryo-EM maps [10]. However

Recent advances in the stereoselective synthesis of distal biaxially chiral molecules

• Fanxing Zhou,
• Chen Zhang,
• Lingyu Sun,
• Yiyun Fang,
• Siming Zheng,
• Lina Hu,
• Mengyang Shen,
• Zhen Zhao,
• Wei Xu,
• Yunqiang Sun and
• Zi-Qiang Rong

Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34

• alkylation for dynamic kinetic resolution. Moreover, additional alkylation at a sterically congested second rotational axis enabled the construction of remote, double axially chiral molecules 26. Further advances have come from transition-metal catalysis. Li’s group established a rhodium-catalyzed protocol

• organocatalytic approach. The mechanistic study revealed that the reaction proceeds through a stepwise double cyclization process: The first cyclization generates an intermediate bearing a stereogenic axis, while the second cyclization involves dynamic kinetic resolution of the spiral reaction intermediate under

• biaxial terphenyl atropisomers with chlorinated and brominated variants to achieve high diastereo- and enantioselectivity. The process takes place via a two-step kinetic resolution. In 2021, Shi and co-workers reported a highly trans-selective synthesis of axially chiral styrenes 76 containing a

Synthesis and stereochemical analysis of dynamic planar chiral oxa[7]orthocyclophene

• Yukiho Hashimoto,
• Yuuya Kawasaki,
• Kazunobu Igawa and
• Katsuhiko Tomooka

Beilstein J. Org. Chem. 2026, 22, 436–442, doi:10.3762/bjoc.22.30

• nm). Plausible phenyl-substituent effect on the stereochemical stability of 1ac. Kinetic measurements for the racemization of 1ab and 1ad. HPLC analysis of 1ab and 1ad using a CD detector at 5 °C (OJ-H column, 4.6 mm × 250 mm, eluent: hexane/iPrOH 95:5, flow rate: 0.5 mL/min, monitoring wavelength

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• thermodynamic and kinetic stability of the capsules and the guest exchange processes [55][56][57][58][59][60]. This has made dimerization of tetraureacalix[4]arenes one of the most explored self-organization processes in calixarene supramolecular chemistry, which has been used in the template synthesis of

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• corresponding amide products 26 were obtained using only 10−4 mol % Pd(COD)Cl2 in combination with 1-benzyl-1H-1,2,3-triazole (L1). Based on kinetic curves, TEM images, catalyst poisoning experiments, MS identification of intermediates, and EPR spectra of the crude mixture, the authors proposed two kinetically

• reacted smoothly with p-methoxyphenyl (PMP) amine, p-methoxybenzyl (PMB) amine, N-benzyl-N-methylamine, and indole, generating the corresponding amides 99–102 in good to excellent yields. Based on kinetic studies, the authors proposed a plausible mechanism in which the dihydrogen tetrametaphosphate

Arene activation via π-bond localization: concepts and opportunities

• Paul Meiners,
• Julian J. Melder and
• Tobias Morack

Beilstein J. Org. Chem. 2026, 22, 257–273, doi:10.3762/bjoc.22.19

• arene activation offers powerful opportunities in reactivity design. Notably, the small-ring annelation exerts a dual influence: it lowers kinetic barriers and enhances regioselectivity, with strain-release providing the key thermodynamic driving force to overcome aromatic stabilization. Synthetic

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• renders the pyranoquinoline carbonyl more electrophilic than that of the acyclic ester, facilitating its alcoholysis at elevated temperature and extended reaction times. Consequently, pyranoquinolines may be regarded as kinetic products, formed rapidly under mild conditions, whereas the open-chain esters

• derivatives. These 3-(4-hydroxyquinolin-3-yl)propanoate esters were previously inaccessible, as earlier protocols consistently afforded cyclic pyranoquinolinones. Pyranoquinolinones are the kinetic products, whereas the open-chain esters represent the thermodynamically favored species formed via controlled

Screwing the helical chirality through terminal peri-functionalization

• Devesh Chandra,
• Sachin and
• Upendra Sharma

Beilstein J. Org. Chem. 2026, 22, 205–212, doi:10.3762/bjoc.22.14

• through a catalytic kinetic resolution (KR) process was developed by Liu and co-workers [32]. The authors screened a range of organocatalysts, i.e., Takemoto’s thiourea catalyst, (S,S)-1,2-cyclohexanediamine-derived thioureas, cinchona alkaloid-derived thiourea, and squaramides to achieve the desired

• enantioselectivity. Notably, [6]helicene 3k was also readily produced, via kinetic resolution (Scheme 1). Computational studies suggested that hydrogen bonding and π interactions between the reactants and catalyst L1 controlled the stereochemical output of the products 3. The catalyst proximate both reactants to

• helical chiral entities was reported by Wang and co-workers. They reported an organocatalyzed asymmetric synthesis of phosphorus-containing chiral helicenes enabled by dynamic kinetic resolution using copper and peptide-mimetic phosphonium salts, i.e. amino acid-derived phosphonium iodide and bromide as

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• in water of 8.5 ± 0.3 mg/mL, leading to a solution with a pH of 6.24 ± 0.01. However, the kinetic solubility appears low; when preparing a solution of 5 mg/mL, the container must be shaken for several minutes. Previously, we reported the solubility of 1 in buffer at pH 7.4 to be 0.4 mg/mL, which is

Circumventing Mukaiyama oxidation: selective S–O bond formation via sulfenamide–alcohol coupling

• Guoling Huang,
• Huarui Zhu,
• Shuting Zhou,
• Wanlin Zheng,
• Fangpeng Liang,
• Zhibo Zhao,
• Yifei Chen and
• Xunbo Lu

Beilstein J. Org. Chem. 2026, 22, 158–166, doi:10.3762/bjoc.22.9

• previously disclosed a PIDA-mediated oxidative strategy for alcohol incorporation via activation of the S–NH bond (Scheme 1a) [14]. More recently, Wu and co-workers advanced the field by developing a dynamic kinetic resolution protocol for the enantioselective synthesis of sulfinimidate esters from racemic

• exceeds the theoretical maximum of 23% expected from the starting diastereomeric ratio, suggesting that the two diastereomers of 5 did not react at identical rates. These results are consistent with a partial kinetic resolution, wherein the major diastereomer of 5 reacts preferentially, leading to the

• reactivities of the two diastereomers. Although these findings strongly support the occurrence of a partial kinetic resolution, further kinetic measurements would be required for definitive confirmation. A plausible mechanism is outlined as follows. First, the sulfenamide 1 is oxidatively brominated by N

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• hydrogenation reaction (Scheme 7) [60]. Using an acid-assisted dynamic kinetic resolution method, they obtained a series of chiral indolines 56 containing exocyclic stereocenters in high yields and excellent enantioselectivity. Mechanistic studies of the reaction revealed that the dynamic kinetic resolution

• the reaction include high functional group tolerance and excellent stereocontrol. In the same year, Zhou and co-workers reported a rhodium/bisphosphine-catalyzed asymmetric hydrogenation reaction of all-carbon aromatic rings 69 (Scheme 8) [64]. Through desymmetrization or kinetic resolution, a series

• protonation during reduction or an isomerization event. Kinetic translocation of the double bond to the correct position enabled an intramolecular Heck reaction, a transformation originally developed by Fukuyama (Scheme 12) [78]. Hydrogenation of (−)-tabersonine to (−)-decahydrotabersonine by Catherine

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• attracted our interest, prompting a more detailed investigation. Kinetic studies with acetophenone revealed an induction period prior to reaction onset (Figure 5). Elevated temperatures shortened the initiation time, whereas lower temperatures extended it to several hours. Both temperature and reaction time

Recent advances in total synthesis of illisimonin A

• Juan Huang and
• Ming Yang

Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199

• reaction of 87 was employed, generating both the kinetic product 88 and the desired thermodynamic product 89. Heating 88 promoted a retro-Diels–Alder/Diels–Alder equilibrium, favoring the more stable isomer 89. Palladium-catalyzed hydrogenation of the 1,2-disubstituted alkene in 89, followed by Mo(CO)6

Palladium-catalyzed regioselective C1-selective nitration of carbazoles

• Vikash Kumar,
• Jyothis Dharaniyedath,
• Aiswarya T P,
• Sk Ariyan,
• Chitrothu Venkatesh and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2025, 21, 2479–2488, doi:10.3762/bjoc.21.190

• that the cyclopalladation step is irreversible. To further investigate the nature of the C–H activation step, an intramolecular kinetic isotope effect (KIE) experiment was performed using monodeuterated substrate 1a-D1. A modest KIE value of kH/kD = 1.5 was observed under standard reaction conditions

Catalytic enantioselective synthesis of selenium-containing atropisomers via C–Se bond formations

• Qi-Sen Gao,
• Zheng-Wei Wei and
• Zhi-Min Chen

Beilstein J. Org. Chem. 2025, 21, 2447–2455, doi:10.3762/bjoc.21.186

• catalytic performance. The developed catalytic system demonstrated high activity, excellent yields (mostly exceeding 85%), mild reaction conditions, broad functional group tolerance, as well as high regioselectivity, (E)-selectivity, and enantioselectivity (up to 99% ee). According to the kinetic study, the

Adaptive experimentation and optimization in organic chemistry

• Artur M. Schweidtmann and
• Philippe Schwaller

Beilstein J. Org. Chem. 2025, 21, 2367–2368, doi:10.3762/bjoc.21.180

• . provide a comprehensive review of machine learning applications in enantioselective organocatalysis, highlighting both achievements and remaining challenges [10]. Guo et al. present an automated flow chemistry system for nitration reactions, combining kinetic modeling with experimental optimization [11

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• pyridinium site. This light-driven shuttling was shown to be fatigue-resistant over multiple cycles, highlighting the robustness of the system. Notably, the authors also reported a general quantification of kinetic asymmetry in a multicycle chemical reaction network, establishing a framework applicable to

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• (20 mg) is used. Kinetic studies conducted for both hosts H2 and G2W1 in the removal of methylene blue and methylene violet, respectively, demonstrate a rapid sequestration process that reaches a plateau within 30 minutes. In conclusion, this study highlights the importance of avoiding host structural

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• oxymethylene bridge in the 2D NOESY NMR spectrum. Given the instability of fluoro-ketone 13, a one-pot procedure was developed in which the reaction mixture containing 13 was subjected to the Baeyer–Villiger oxidation with H2O2 giving the fluorinated and stable lactone 14, which is the expected kinetic product

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• regulatory role in chemical transformations, exerting kinetic modulation through solvation effects on activation barriers and reaction rates, dictating thermodynamic equilibria that govern product distribution, and enabling precise reaction pathway regulation via selective stabilization of critical

• control principles for gold catalysis. Temperature-controlled cyclization of 1,n-enynes Temperature, a pivotal thermodynamic parameter, not only governs reaction kinetics but also determines reaction pathways. Typically, kinetic product formation is favored at lower temperatures via pathways with reduced

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• physicochemical and early ADME characterization study, in the framework of which logP, pKa and logk values were calculated. Following that, kinetic solubility and in vitro gastrointestinal membrane-specific permeability measurements were carried out to assess the lead-likeness of the compounds. Subsequently, the

• results of physicochemical and early ADME characterization for hydrazones 7 and 9, and target compounds 3 and 10 are summarized in Table 2 and Table 3, respectively (individual column charts on kinetic solubility, permeability, and membrane retention measurements can be found in Supporting Information

• surface area (TPSA) values fell in a desirable range (40–90 Å2) (see the extended table on physicochemical parameters in Supporting Information File 1, Table S1). Based on their pKa values, all compounds are non-ionizable or slightly basic. Kinetic solubility was considered good above 30 µM, moderate

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

• 50% yield and 99% ee after kinetic resolution using Escherichia coli (Scheme 57) [189]. Other reactions: Yamamoto synthesized 6-hydroxy-2-(trifluoromethyl)-2H-pyran-3(6H)-ones from furfural via trifluoromethylation using the Ruppert–Prakash reagent (TMSCF3), followed by a photo-Achmatowicz reaction