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

• conditions, (S,S)-2 was the sole AMD product and the formation of the respective mesomeric stereoisomer was negligible. It should be noted that this work is a rare example of catalytic asymmetric synthesis of planar-chiral CpMn(I) half-sandwich complexes [19][32]. Results and Discussion Preparation of

• conditions (Table 1, entry 2). The Mo/(R)-L3 precatalyst [23] showed the highest catalytic activity among examined. Although the enantioselectivity was excellent (krel = 107), the diastereoselectivity was poor (Table 1, entry 3). At 10 °C using Mo/(R)-L1, enantioselectivity was greatly improved in the AMD/KR

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• synthesis of 4 and its possible isomer 3, the required compounds 1 and 2 were synthesized as a mixture of the isomers starting from chromene 5, briefly heated in a closed microwave apparatus with catalytic amounts of acetic acid. Forced heating of 5 in acetic acid or use of stronger acids lead to the

• made to cyclize 5 into melifolione B (2) with the following results (Scheme 1) Heating of 5 in DMF at 100 °C yielded melifolione A (1) with traces of melifolione B (2). When 5 was heated in acetic acid at 80 °C, only benzoxocin 6 could be isolated. Reaction of 5 with catalytic amounts of p

• ), but the yield was less than 5% and therefore of no preparative interest. The best results to get melifolione B (2) were achieved by briefly heating 5 in a closed microwave apparatus without solvent at 130–140 °C after addition of catalytic amounts of acetic acid. By this procedure, the proportion of 2

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

• thereafter, Nasam and co-workers developed a novel synthesis of 1`s fragment 272 using multiple asymmetric catalytic transformations (Schemes 29–31) [102]. 256 was synthesized from trans-crotonic acid and served as a starting material for the first building block (261, Scheme 29). Hosomi–Sakurai allylation

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

• LE1 7RH, UK 10.3762/bjoc.22.35 Abstract Class I histone deacetylases (HDACs 1–3) serve as catalytic subunits within seven multiprotein co-repressor complexes, each of which has distinct functions in the cell. We report the synthesis of a HDAC inhibitor–nanogold probe, derived from the class I HDAC

• inhibitor CI-994, for cryo-electron microscopy (cryo-EM) visualization of the HDAC catalytic domain within class I HDAC co-repressor complexes. The nanogold probe retained HDAC inhibitory activity comparable to CI-994 against the HDAC1-LSD1-CoREST complex in vitro. In cryo-EM studies, 2D class averages

• revealed the bi-lobed architecture of the CoREST complex and partial localization of the gold nanoparticle probe to the CoREST complex. However, the probe was not observed in classes showing the side-view of the CoREST complex, limiting unambiguous identification and positioning of the HDAC catalytic

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

• in catalysis, drug discovery, and functional materials. Review One-step construction of remote biaxial chiral molecules In recent years, the development of asymmetric catalytic methods, including both transition-metal catalysis and organocatalysis, has provided powerful tools for the one-step

• demonstrated that such one-step catalytic approaches not only streamline the synthesis of structurally complex biaxial molecules but also open new avenues for their applications in catalysis, drug discovery, and functional materials. In 2004, Shibata and co-workers reported a novel iridium-catalyzed asymmetric

• remote biaxial chiral ligands 21 (Scheme 4) [45]. These ligands were successfully applied in asymmetric hydrogenation, revealing dual asymmetric induction effects and enriching the design principles for chiral catalytic systems. In addition, Yan’s group developed an organocatalytic strategy for the

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• inhibits glutaminase by covalently labeling the catalytic serine [8]. DON inhibits other glutamine-utilizing enzymes such as asparagine synthetase and has activity against a wide range of cancer cell lines [9][10]. BPTES is a potent allosteric inhibitor of GAC/KGA that binds at the dimer–dimer interface

A facile and practical method for the synthesis of trans-(±)-taxifolin and its derivatives via Darzens reaction

• Bo Peng,
• Panpan Yang,
• Maaz Khan,
• Xiaotong Lin,
• Jiang Wu,
• Peng Fu and
• Qingqing Wu

Beilstein J. Org. Chem. 2026, 22, 443–450, doi:10.3762/bjoc.22.31

• favorable to catalyze the Darzens reaction [31][33], and some commonly used Lewis acids (Table 1, entries 17–22) were studied. The results showed that the addition of catalytic amounts of Lewis acids remarkably accelerated the reaction which was completed within 4 h while the yield was not affected. Among

• (1.2 equiv) was performed in CH3CN, using t-BuOLi (1.2 equiv) as base in the presence of a catalytic amount of ZnCl2. Due to the high efficiency of the reaction, no purification of product (±)-4a by column chromatography was necessary after post-treatment and the product could be directly used in the

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

• coupling of compound 1ad with MeMgBr and PhMgBr in the presence of a catalytic amount of NiCl2(PPh3)2 proceeded smoothly to provide the C6-methyl-substituted 1ab in 79% yield and the C6-phenyl-substituted 1ac in 99% yield (Scheme 3) [15][16]. Suitable single crystals were obtained from racemic 1ac, and its

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

• narrow rim was obtained in 97% yield. Still, the deprotection of calixarene 23 to the desired propargyl ether 26 was far from complete even under heating, which significantly reduced the yield of this compound (Scheme 4). The difference in the efficiency of catalytic removal of the TBS groups observed

• for calixarenes 21–23 may be due to a reaction rate enhancement upon increasing the number of TBS-protected propargyl groups attached to the same calixarene core. Tentatively, this rate enhancement may be due to entrapment of the catalytic F– and/or water molecule(s) inside a pocket formed by the four

• hampering or preventing a catalytic hydrogenation of these compounds. On the other hand, in calixarenes 31 and 32, which are immediate products of the selective reduction of the nitro groups in compounds 29 and 30 under neutral or basic conditions, the free amino groups may be alkylated by a neighboring

Non-central chirality in organic chemistry

• Ken Tanaka and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2026, 22, 370–371, doi:10.3762/bjoc.22.24

• remote from the reaction site. Second, non-central chiral frameworks remain fertile ground for catalyst design, not only as derivatives of established motifs but also as newly conceived architectures that redefine how chirality can be embedded into catalytic systems. Third, the pronounced chiroptical and

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

• , respectively. N-Phenylbenzamide (5) also afforded 1 in 86% yield. Secondary and tertiary acetamides 6–8 were also successfully cleaved, affording the product 2 in high yields. The CeO2 catalyst was recyclable, although a slight decrease in yield was observed upon reuse. Notably, catalytic activity was fully

• for the hydrolysis of amides (Scheme 3) [47]. In the presence of a catalytic amount of Nb2O5, N,N-dialkylamides 3 and 4 and anilides 5 and 10 were efficiently converted into the corresponding carboxylic acids 9 in high yields, and the Nb2O5 catalyst could be successfully recycled. The authors proposed

• good to high yields. The authors proposed that a manganese–potassium heterodinuclear alkoxylate complex F, formed from Mn(acac)2(Me2N-Phen), potassium methoxide, and n-butanol, serves as the key catalytic species. The dinuclear complex stabilizes the relevant transition states and intermediates

Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls

• Mark M. Gulman,
• Yuliya F. Polienko,
• Sofia Yu. Trakhininа,
• Yuri V. Gatilov,
• Tatyana V. Rybalova,
• Sergey A. Dobrynin and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22

• catalytic system comprising PPh3, CuI, and Pd(PPh3)2Cl2. This procedure afforded alkynones 6a,b in the yields of 75% and 44%, respectively (Scheme 3). In the IR spectra of 6a,b intense bands were observed at 2212–2214 and 1645–1647 cm−1, assigned to vibrations of the triple bond, and the conjugated carbonyl

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

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

• as well as transition metal coordination to aromatic fragments in an η2-, η3-, and η4-fashion. The structural and reactivity consequences of these perturbations are analyzed in detail, and representative examples of stoichiometric and, where available, catalytic applications in synthesis are

• dearomatization is poised to open the door to new avenues of synthetic discovery. However, unlocking the full potential of arene π-bond localization as a synthetic strategy is contingent on its successful translation into a catalytic framework, which fundamentally requires the activation to be external. The

• following sections therefore focus on the selective disruption of aromaticity through the formation of transition metal–arene π-complexes. Transient and reversible coordination of transition metals to aromatic π-systems is a key feature of many catalytic transformations, with the oxidative addition of

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

• the presence of catalytic DMF in ethanol (Scheme 3a) [40]. A small amount of ethanol ensured homogeneity of the reaction mixture, allowed gradual temperature increase, and prevented sudden charring. DMF, with its high boiling point, acted as a homogenizer by preventing solidification after ethanol

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• esters could be slightly improved by using a catalytic amount of 1-butylimidazole; however, in the present work, a catalyst was not employed to simplify the purification step. The reaction temperature in this process should have been set to 230 °C. However, at this temperature, a burnt black material was

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

• [22][23]. A very recent study also highlighted their potential application in biological interfaces [1], thus highlighting the versatility of helicenes in medicine along with next-generation materials and catalytic systems. Due to the above-mentioned applications of chiral helicenes various synthetic

• 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

• and with excellent enantioselectivities. The catalytic system operated under mild conditions within a practical timeframe and demonstrated broad substrate tolerance, providing a range of chiral helicenes. Notably, unsymmetrical phosphine oxides also underwent smooth Michael addition, with excellent

Base-promoted deacylation of 2-acetyl-2,5-dihydrothiophenes and their oxygen-mediated hydroxylation

• Vladimir G. Ilkin,
• Margarita Likhacheva,
• Igor V. Trushkov,
• Tetyana V. Beryozkina,
• Vera S. Berseneva,
• Vladimir T. Abaev,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2026, 22, 192–204, doi:10.3762/bjoc.22.13

• Oxidative transformations are an important area of modern organic synthesis [1], producing a broad range of valuable synthetic products for the industry. A variety of catalytic reactions were developed for the oxidative conversions of unsaturated compounds [2][3][4][5], alcohols [6][7], alkanes [8][9][10

•  1A) [15][16]. Oxidative rearrangements of carbonyl compounds are based on Dakin [17] and Baeyer–Villiger reactions [18] and their modifications. Cyclic and acyclic ketones were oxidized to afford lactones and esters, accordingly, involving catalytic reactions with hydrogen peroxide [19][20][21][22

• ], oxygen [23][24] or with m-CPBA (Scheme 1B) [25][26] or non-catalytic transformations [27]. The few known oxidative transformations of o- or p-hydroxy-substituted aromatic ketones, that in most cases lead to phenols, involve the use of hydrogen peroxide as an oxygen source (Scheme 1C) [20][25][26

Asymmetric Mannich reaction of aromatic imines with malonates in the presence of multifunctional catalysts

• Kadri Kriis,
• Harry Martõnov,
• Annette Miller,
• Mia Peterson,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2026, 22, 151–157, doi:10.3762/bjoc.22.8

• ], halogen bonding is more frequently employed as a component of multifunctional catalytic systems [23][24][25]. Multifunctionality of the catalyst is essential to intensify weak noncovalent interactions. Results and Discussion As a continuation of our previous studies [18][24], we now report an asymmetric

• catalyst and the imine and malonate attacks from si-face affording the product in S-configuration (Figure 2). To demonstrate the utility of the elaborated catalytic system, the Mannich reaction between aromatic imines, both with electron-withdrawing and electron-donating substituents in the phenyl ring

• method and applications of obtained products are under study. Experimental General procedure for the catalytic asymmetric Mannich reaction Catalyst E (2.7 mg, 0.0057 mmol, 0.01 equiv) was weighed into a reaction vessel, imine (0.057 mmol, 1.0 equiv) and toluene (285 µL) were added. The mixture was

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

• saturation the aromatic ring facilitates synthetic chemists to efficiently synthesize natural products with complex three-dimensional structures. Recent advances in catalyst and ligand design have enabled unprecedented progress in the catalytic hydrogenation of (hetero)aromatic systems. Quinoline

• , isoquinoline, pyridine, and related substrates can now be reduced with high efficiency and stereoselectivity, providing efficient access to saturated and partially saturated architectures vital to synthetic chemistry. Furthermore, catalytic asymmetric aromatic hydrogenation has facilitated the asymmetric total

• synthesis of complex natural products and pharmaceutical agents. This review highlights recent advances in catalytic (hetero)arene hydrogenation, with a focus on its application in natural product synthesis. Keywords: aromatic rings; dearomatization; hydrogenation; natural products; total synthesis

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• and accelerating the whole process. Zr-mediated catalytic radical reactions In recent years, numerous chemical transformations employing photoredox catalysts in combination with catalytic amounts of zirconium complexes have been reported. In this section, representative examples of such reactions are

• the strong affinity of zirconium for halogens, they developed a catalytic system to address this issue. Treatment of alkyl chloride 34 with zirconocene bistosylate in the presence of an Ir-photoredox catalyst promoted halogen atom transfer to generate alkyl radical 35. This radical then abstracted a

• yields. The catalytic system was further extended to the borylation of alkyl chlorides. (Scheme 7B). Under XAT conditions with B2(cat)2, the in situ-generated alkyl radical was trapped by diborane compound to form intermediate 39, which was subsequently converted into pinacol boronate 40 upon treatment

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

• stereocontrolled olefin metathesis with molybdenum catalysts to access trisubstituted alkenes including alkenyl chlorides (Figure 3H) [39]. Two recent reviews by Lu [40] and Nishiwaki [41] provide overviews of current developments in the hydrochlorination of alkynes, highlighting emerging catalytic strategies

• of the desired products (Scheme 20B). The authors proposed that BTC functions by regenerating benzoyl chloride in situ from benzoic acid, thereby allowing the use of benzoyl chloride in catalytic quantities (Scheme 20C). Under similar conditions – benzoyl chloride (2.2 equiv), room temperature

• ZnCl2·etherate exhibits superior catalytic activity compared to anhydrous ZnCl2. Although counterintuitive from the standpoint of Lewis acidity, this enhanced reactivity was attributed to the significantly improved solubility of the etherate complex, which compensates for its diminished intrinsic Lewis

Total synthesis of asperdinones B, C, D, E and terezine D

• Ravi Devarajappa and
• Stephen Hanessian

Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210

• Discussion Adopting approach A, we considered prenylation of the known methyl (2S)-((tert-butoxycarbonyl)amino)-3-(7-iodo-1H-indol-3-yl)propanoate (7) [30] with prenylzinc bromide using a catalytic system reported by Buchwald. In that study, Buchwald’s group achieved the C-6 prenylation of 6-bromoindole in

Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds

• Vasudevan Dhayalan

Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200

• carbonyl compounds and pharmaceutically relevant intermediates. Moreover, this catalytic system operates under green and sustainable conditions, tolerating a broad range of functional groups and substrate scope, and utilizes low-cost, atom-economical, non-toxic starting materials. Keywords: dual catalysis

• functional groups are found in various drugs, natural products, and optoelectronic materials. In the last three decades, N-heterocyclic carbenes (NHCs) have been renowned as versatile organocatalysts, including thiazolium, imidazolium, and triazolium moieties. NHCs are extensively used in many catalytic

• equivalents, which is crucial in dual or triple catalytic cycles. The electron-rich carbene center facilitates faster SET processes in photocatalytic reactions. Triazolium-based NHCs exhibit higher oxidative and photochemical stability, making them well-suited for visible-light-driven catalytic

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

• atmosphere significantly suppressed side reactions, yielding the cyclized product in excellent yield and selectivity. This indicates that N-formylsaccharin, beyond acting as a CO-releasing agent, may function as a ligand in the catalytic cycle to regulate the palladium catalyst’s activity and stability