Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers

• Seeun Lim,
• Teresa Kim and
• Yunmi Lee

Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63

• conditions and shows broad applicability to di- and trisubstituted allenes. Its practicality is demonstrated through the gram-scale synthesis and functional group transformations of amines, amides, and lactams, emphasizing its versatility and synthetic significance. Keywords: α-quaternary nitrile; Cu

• are important intermediates in organic syntheses because of the versatility of the cyano group, which can be readily transformed into a wide range of functional groups, including amides, carboxylic acids, amines, aldehydes, ketones, and N-heterocycles [6][7][8]. However, the synthesis of all-carbon

• with diverse functional groups [12][13][14]. Consequently, the development of selective and predictable strategies for the introduction of cyano groups into quaternary carbon frameworks has become necessary in organic synthesis. The transition-metal-catalyzed hydrocyanation of carbon–carbon double

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• synthesis of various organophosphorus compounds through the formation of phosphorus–carbon, phosphorus–nitrogen, phosphorus–oxygen, phosphorus–sulfur, and phosphorus–selenium bonds. The impact of different electrodes is also discussed in this matter. Graphite, platinum, RVC, and nickel electrodes have been

• used extensively for the electrochemical synthesis of organophosphorus compounds. The recent advances in the electrochemical synthesis of organophosphorus compounds have made this method a promising method for preparing various structures. This review is an introduction to encourage scientists to use

• electrosynthesis as a green, precise, and low-cost method to prepare phosphorous structures. Keywords: electrosynthesis; green synthesis; organophosphorus compounds; P–C bond formation; P–heteroatom bond formation; Introduction The electrochemical synthesis is a valuable and beneficial method for the preparation

New advances in asymmetric organocatalysis II

• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60

• as the eco- and user-friendliness of asymmetric organocatalysis contribute to its growing applicability in the synthesis of complex target molecules, such as therapeutic agents [17][18]. However, nowadays organocatalysis does go well beyond the boundaries of organic chemistry. This can also be seen

• Malkov reviewed the recent progress in the organocatalytic synthesis of chiral homoallylic amines. This important structural motif is typically made by asymmetric allylation of imines, and the authors describe various catalytic approaches as well as applications of these strategies in total synthesis [25

Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• hydrocyanation of hydrazones, catalyzed by a calcium–BINOL phosphate complex, has been studied for the first time both experimentally and computationally with DFT methods. A full catalytic cycle for the enantioselective synthesis of α-hydrazinonitriles is proposed based on insights gained from DFT calculations

• enantioselectivity achieved with the calcium catalyst remains modest, mainly due to competing pathways for the Z- and E-hydrazone isomers leading to opposite enantiomers. The experimental results confirm these computational proposals. Keywords: asymmetric synthesis; calcium–BINOL phosphate catalysis; hydrocyanation

• through calcium catalysis [8][9][10]. Asymmetric synthesis has also been achieved via, e.g., 1,4-addition and [3 + 2] cycloaddition of 3-tetrasubstituted oxindoles with a calcium Pybox catalyst [11][12], or through enantioselective Friedel–Crafts and carbonyl–ene reactions [13]. Since the pioneering

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• report the copper-catalyzed synthesis of tetrahydroquinoline derivatives via a domino reaction of aniline with cyclobutanone oxime. This method demonstrates a selective approach for generating bioactive tetrahydroquinoline scaffolds, which have broad applications in pharmaceutical chemistry. The reaction

• the desired product. Keywords: copper catalysis; cyclobutane-fused tetrahydroquinolines; domino cyclization reaction; green synthesis; Introduction Tetrahydroquinolines (THQs) represent a privileged scaffold in medicinal chemistry, exhibiting a broad spectrum of biological activities and serving as

• therapeutic development. The strained cyclobutane ring, in particular, acts as a versatile and conformationally constrained building block, enabling the construction of complex molecular architectures with potent biological activities [22]. Despite their promise, the synthesis of cyclobutane-fused THQs

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• potency as inhibitors of Man-specific bacterial adhesion investigated. Results and Discussion Synthesis For the preparation of the homobivalent glycocluster 6αMan3αMan 2, the known mannosyl thioacetate 7 [31] was prepared from the trichloroacetimidate 6 [32] and thioacetic acid in an α-selective reaction

• 3-O-(mannosyloxyazobenzene)-6-thio-mannoside 11 was employed, which was prepared according to a known procedure applied for the synthesis of the heterobivalent glycocluster 6βGlc3αMan 1 (cf. Supporting Information File 1, Scheme S1). The cross-coupling of thiol 11 with the azobenzene

• α-ᴅ-mannopyranosyloxyazobenzene mannosides 6βGlc 3 and 6αMan 4 were prepared first (Scheme 2A). The synthesis of the β-ᴅ-glucopyranosyl mannoside 6βGlc 3 started from the literature-known S,O-acetylated mannoside 13 [35], which was chemoselectively deprotected at the 6-position employing DTT (1,4

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• )cyanophenylacetonitrile) fluorophores for easy access, which will contribute to the rapid dissemination of the RNA imaging approaches associated therewith. Keywords: covalent RNA labeling; FLAP; fluorophore synthesis; HBC530; self-alkylating ribozymes; Introduction The discovery of fluorescent reporters, such as green

• research group has recently developed the first covalent FLAP system (coFLAP) based on the Pepper aptamer and demonstrated some advantages of the covalent (coPepper) over the non-covalent (Pepper) reporter in RNA imaging (Figure 1) [11]. Here, we describe the full synthesis of “self-attaching” Pepper

• have shown that this feature can be exploited to construct a covalent bond between the fluorophore and the RNA by replacing the N-hydroxyethyl group of the dye with an electrophilic handle, resulting in efficient RNA alkylation at the N7 of G41 [11]. Synthesis and evaluation of Pepper dyes with an

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• Christian Akakpo Peter Y. Zavalij Lyle Isaacs Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States 10.3762/bjoc.21.55 Abstract We report the synthesis and characterization of a new acyclic cucurbit[n]uril (CB[n]) host C1 that features four

• supramolecular chemistry involves the synthesis of macrocyclic hosts and studies of their molecular recognition properties. The most widely studied macrocyclic host systems include those created entirely by covalent bonds (crown ethers, cyclodextrins, calixarenes, cyclophanes, pillararenes, cucurbit[n]urils (CB

• modular synthesis, acyclic CB[n] can be easily modified synthetically [42][43][44][45][46][47][61]. Acyclic CB[n]-type receptors featuring different length glycoluril oligomers (monomer–pentamer) and different aromatic walls (e.g., naphthalene, anthracene, triptycene) have been studied [42][62][63][64][65

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• the corresponding parent phenacenes PIC, FUL, and 7PHEN to reveal the effects of the fluorination at the terminal rings. Results and Discussion Synthesis of F8-phenacenes The synthetic routes to building blocks 10, 13, and 15 and those to the desired F8PIC, F8FUL, and F87PHEN are respectively shown in

• state. The orange and blue sites, respectively, indicate negative and positive regions (−0.02 ≈ 0.02 hartree). Synthesis of building blocks 10, 13, and 15. Reagents and conditions: a) NaBH4, MeOH, THF, reflux; b) PBr3, reflux; c) N-methylmorpholine-N-oxide, THF, reflux; d) ethylene glycol, p-TsOH

• , toluene, reflux; e) tert-BuLi, DMF, THF, −78 °C; f) KOH, 18-crown-6, CH2Cl2, reflux (rt for 8); g) hν, I2, cyclohexane (toluene/THF mixture for 11); h) p-TsOH, acetone, reflux. Synthesis of F8PIC, F8FUL, and F87PHEN. Reagents and conditions: a) KOH, 18-crown-6, CH2Cl2, reflux; b) hν, I2, toluene, rt

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• diastereomerically pure γ‑branched fluorinated amino acids. This work further underlines the importance of chiral Ni(II) complexes in the synthesis of fluorinated amino acids. Keywords: chiral nickel complexes; fluorinated amino acids; gram-scale amino acid synthesis; stereoselective synthesis; Introduction Non

• chiral nickel complexes. In recent years, the Soloshonok working group demonstrated the synthesis of non‑natural amino acids using the corresponding chiral Ni(II) complex [7]. In addition to the high enantiomeric purity of the corresponding products, the scale of the reaction, which extends into the

• ) complex with the corresponding fluorinated alkyl iodide. The aryl moiety of the Ni(II) complex blocks the top face of the complex, ensuring the high diastereoselectivity of this transformation. In principle, synthesis on a gram-scale permits the study of highly fluorinated systems. Recently, we introduced

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• Abstract The transition-metal-catalyzed asymmetric allylic substitution represents a pivotal methodology in organic synthesis, providing remarkable versatility for complex molecule construction. Particularly, the generation and utilization of chiral secondary alkylcopper species have received considerable

• secondary organocopper; copper-mediated reaction; stereoselectivity; Introduction The transition-metal-catalyzed regio- and enantioselective allylic substitution represents a pivotal methodology in organic synthesis, providing remarkable versatility for complex molecule construction [1][2][3][4]. The

• into a powerful and versatile tool in asymmetric synthesis, capable of employing a wide array of organometallic reagents that furnish the desired compounds with high efficiency and selectivity. The regioselective asymmetric construction of stereogenic carbon centers from prochiral allylic substrates

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

• Olesja Koleda,
• Janis Sadauskis,
• Darja Antonenko,
• Edvards Janis Treijs,
• Raivis Davis Steberis and
• Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

• Olesja Koleda Janis Sadauskis Darja Antonenko Edvards Janis Treijs Raivis Davis Steberis Edgars Suna Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga LV-1006, Latvia Faculty of Medicine and Life Sciences, Department of Chemistry, University of Latvia, Jelgavas 1, Riga LV-1004, Latvia

• 10.3762/bjoc.21.50 Abstract The electrochemical synthesis of 2-aminoprolines based on anodic decarboxylation–intramolecular amidation of readily available N-acetylamino malonic acid monoesters is reported. The decarboxylative amidation under Hofer–Moest reaction conditions proceeds in an undivided cell

• and the development of efficient synthetic methods to access these medicinally relevant structural motifs. Herein, we report an electrochemical synthesis of 2-aminoproline and 2-aminopipecolic acid derivatives 6 (Figure 1). Recently, we disclosed an electrochemical approach to tetrahydrofuran and

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• proteins. By harnessing light to drive chemical transformations, photoredox techniques can facilitate the synthesis of antibody bioconjugates. This perspective will discuss the drive to develop and empower photoredox methods applied to antibody functionalization. Keywords: antibodies; bioconjugation

• facilitate various modifications, including labeling, crosslinking, and the creation of protein–drug conjugates. The incorporation of photoredox strategies has facilitated the synthesis of complex protein architectures, enabling precise control over conjugation sites and degrees of modification. The number

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• products can serve as effective scaffold for the design and synthesis of derivatives with improved biological activities [5][6][7]. Massarilactones are produced by marine and endophytic fungi and bear close biogenetic similarity to several other fungal PKS1-derived metabolites including rosigenin, the

• , as indicated by structure–activity relationship analysis. Conclusion In the present study, the use of various acylating reagents to modify massarilactone D introduces distinct functional groups, each with unique chemical properties. This approach led to the synthesis of seven previously undescribed

Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions

• Xiao-Yang Bi,
• Xiao-Shuai Yang,
• Shan-Shan Chen,
• Jia-Jun Sui,
• Zhao-Nan Cai,
• Yong-Ming Chuan and
• Hong-Bo Qin

Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47

• Xiao-Yang Bi Xiao-Shuai Yang Shan-Shan Chen Jia-Jun Sui Zhao-Nan Cai Yong-Ming Chuan Hong-Bo Qin School of Chemistry and Environment, Yunnan Minzu University, Kunming 650000, China 10.3762/bjoc.21.47 Abstract The total synthesis of (±)-simonsol C was accomplished using a dearomatization under

• acidic conditions as key step to construct an aryl-containing quaternary center. The 6/5/6 benzofuran unit was formed through reductive elimination with Zn/AcOH and a spontaneous oxy-Michael addition. This synthesis consists of 8 steps and achieves an overall yield of 13%, making it the shortest known

• route. Keywords: acidic dearomazation; benzofuran; (±)-simonsol C; total synthesis; Introduction Star anise, derived from Illicium species cultivated in southeastern China [1] possesses significant economic, culinary, and medicinal value [2]. Particularly noteworthy are its medicinal properties

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• this study, we present an innovative, sustainable approach to synthesizing hydantoins (H2a–j) directly from amino acids. This method employs a column chromatography-free, two-step, one-pot microwave-assisted synthesis that delivers hydantoins in yields ranging from 34% to 89%. The protocol demonstrates

• exceptional functional group tolerance, accommodating phenyl, aliphatic, phenol, alcohol, heterocyclic, and sulfide groups. This scalable, rapid, and eco-friendly strategy offers a promising avenue for the efficient synthesis of hydantoins, aligning with green chemistry principles and expanding the

• accessibility of these bioactive compounds for pharmaceutical applications. Keywords: amino acids; hydantoin; microwave-assisted; one-pot reaction; Urech synthesis; Introduction The hydantoin moiety is a scaffold found in many biologically active compounds exhibiting a diverse range of properties, including

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• implementation often implies fewer purification steps to achieve the target molecules, leading to a reduction of waste, when compared to traditional “step by step” synthesis. Another advantage of MCRs is that by selecting appropriate starting materials, follow-up functionalization by, e.g., post-cyclization of

• . Synthesis of heteroaromatic systems One of the most powerful applications of MCRs is the synthesis of heterocyclic compounds and several reports in recent years showed the advantages of using this tool as a synthetic strategy to generate complex molecular scaffolds with medicinal relevance [25][26][27]. In

• separation processes are required [32][35][36]. In this context, DMSO has been used as an alternative to formaldehyde for the MCR synthesis of a wide variety of quinolines and related compounds. For example, Zhang et al. showed that starting from anilines and substituted styrenes while using K2S2O8 for the

Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• , interaction with dinucleophiles results in recyclization accompanied by opening of the furan ring. Relied on the aforementioned process a general method for the synthesis of substituted pyrazol-3-ones with allomaltol fragment was designed. Structures of representatives of all obtained products were

• intramolecular hydrogen bond between the NH-unit and the carbonyl group. The presented results indicate that the reaction of the aliphatic amine doesn’t lead to recyclization of the studied heterocyclic system. Further, we hypothesized that synthesis of the enamine 4a can be realized in one-pot variant without

• conditions and the obtained results are summarized in Table 1. It should be mentioned that all experiments were carried out at reflux due to low solubility of the starting compound 1a in all used solvents. At first, we carried out the process under conditions developed above for the synthesis of enamines 4

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• of its unique interaction in organic synthesis. Chiral halonium salts have been found to have strong halogen-bonding-donor abilities and work as powerful asymmetric catalysts. Recently, we have developed binaphthyl-based chiral halonium salts and applied them in several enantioselective reactions

• , which formed the corresponding products in high to excellent enantioselectivities. In this paper, the asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon stereogenic centers by the Mannich reaction through chiral halonium salt catalysis is presented, which provided the

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• compounds is a significant and important reaction for the selective synthesis of homoallylic alcohols in an efficient and sustainable way [2][3]. As carbonyl compounds, alkyl trifluoropyruvates [4][5] are an interesting class of compounds that have been used in addition reactions of different nucleophiles

• for the synthesis of tertiary trifluoromethyl carbinols [6][7]. In this context, trifluoromethyl carbinols constitute a key structural motif present in a wide range of molecules with important biological activities (Figure 1) [8][9][10], on account of the distinctive properties of organofluorine

• starting materials to study the vinylogous functionalization with alkyl trifluoropyruvates. The synthesis of compounds 3 was accomplished by the reaction of cyclic ketones 1 and 5-aminopyrazoles 2 in the presence of acetic acid (Scheme 1) [30][31]. Cyclohexenones 1a–c provided the corresponding products

Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• derivatives lack a covalent attachment handle. By making use of drug conjugates, toxic payloads such as cryptophycins can be selectively delivered to the target site. We present the synthesis of two conjugable cryptophycins with amino groups in unit B, representing potential payloads for drug conjugates

• chain length [21]. The exchange by an amino group showed a similar trend, however, N,N-dimethylation of the amino group again increased cytotoxicity significantly [20]. Nevertheless, this cryptophycin might only be conjugated via an ammonium-based self-immolative linker [22]. We envisioned the synthesis

• of N-alkylation on the non-chlorinated unit B derivatives. Results and Discussion For the synthesis of unit B derivatives with amino groups instead of the naturally occurring methoxy group ᴅ-phenylalanine served as the fundamental substrate (Scheme 1). Nitration [23] followed by methyl ester

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• increasing n [22]. In this work, we report the first synthesis of ANTH(BnF)n derivatives (n = 1, 2), molecular and solid-state structures, and their photophysical properties. Results and Discussion Synthesis Perfluoroalkylation of anthracene has been previously achieved by bottom-up syntheses [23], three

• with BnFI. While it was possible to prepare ANTH(MgBr)2, the desired product was not formed. Therefore, a photochemical method for the synthesis of 9,10-ANTH(BnF)2 was investigated. Photochemical perfluoroalkylation reactions have attracted attention since 2011 because milder reaction conditions can be

• strips used in this study were measured with a Spectryx SpectryxBlue spectrometer. Fluorescence spectra were recorded using an AVIV ATF‐105 Auto‐Titrating Differential/Ratio Spectrofluorimeter with 90° measurement geometry. Synthesis Method 1 (thermal, solution-phase reactions) Method 1.1 (ANTH, Cu, DMSO

Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• with Grignard reagent, and oxidation with RuCl3/NaIO4. Keywords: aggregation pheromone; chiral 2-methyloxirane; red flour beetle; total synthesis; Introduction The red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), is a cosmopolitan, destructive stored product pest [1], which

• inductive methylation [24]. To research further the bioactivity of the pheromone, herein, we report an effective synthesis of the aggregation pheromone of T. castaneum, which uses the cheap (R)- and (S)-2-methyloxirane as chiral sources, connects two chiral building blocks through Li2CuCl4-catalyzed

• for (4R,8R)-1, the other constituents of the aggregation pheromone (4R,8S)-1, (4S,8R)-1 and (4S,8S)-1 could be prepared. Based on the retrosynthetic analysis of the aggregation pheromone (4R,8R)-1, our synthesis began with the preparation of chiral tosylate (S)-10 (Scheme 2). The ring-opening reaction

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• conventions. Although these dyes have been known since 1978, their photochemistry has only been briefly explored. In this work, during the synthesis of a series of these dyes (Figure 2a), we observed an unprecedented intermolecular [2 + 2] cycloaddition of syn-(ethoxycarbonyl,chloro)bimane (Cl2B), seen in

• , syn-(ethoxycarbonyl,methyl)bimane (Me2B) and syn-(methyl,methyl)bimane (Me4B), were also examined for this phenomenon but did not undergo the reaction. Results and Discussion Synthesis Bimanes are typically synthesized through a three-step process, as outlined in Figure 3. First, a β-keto ester 1

• packing mode. Extra precautions were taken to shield the compounds from light during synthesis, purification, and storage. After crystallizing each bimane, a vial containing multiple crystals was selected for irradiation studies. Cl2B (B), which showed 5% presence of the [2 + 2] dimer after

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• switching efficiency in aqueous solutions. In order to investigate the chemistry of this promising photoswitch and to unlock further applications, we now investigate strategies for the synthesis of derivatives, which are based on cross-coupling reactions. Fourteen vinyl-, aryl-, cyano-, and amino

• [17]. As a starting point for further derivatization, the synthesis and characterization of monohalogenated N-acetyl diazocines 2 and 3 (Figure 1) have been performed [22]. Unfortunately, diazocines in general, and N-acetyl diazocines in particular cannot be derivatized by electrophilic aromatic

• substitution. Substituents such as halogen atoms must be introduced into the N-acetyl diazocine structure during the synthesis of the building blocks. In the present work we start from mono- and dihalogenated N-acetyl diazocine 2–4 (Figure 2) and focus on the further derivatization via cross-coupling reactions