Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• stress (OS) [25]. Alzheimer’s disease (AD) is commonly thought to emerge from a deficiency of the neurotransmitter acetylcholine (ACh) in neuronal and neuromuscular regions, according to the most recognized theory. This deficit may be caused by reduced synthesis or enzymatic function of

• activity towards AβpE3-42 but accomplishing increased solubility. Due to the multifactorial pathogenesis of AD, one of the current drug discovery approaches is the so-called multitarget-directed ligands (MTDLs). In 2015, Benchekroun et al. [38] reported the design, synthesis, and biological evaluation of a

• development as a therapeutic agent for AD. Petasis reaction: Continuing in the context of the development of MTDLs, in 2023 Madhav et al. [40] reported the synthesis of pyrazine-based MTDLs using the Petasis reaction, which involves a secondary amine, a suitable aldehyde, and a substituted boronic acid in the

Surprising acidity for the methylene of 1,3-indenocorannulenes?

• Shi Liu,
• Märt Lõkov,
• Sofja Tshepelevitsh,
• Ivo Leito,
• Kim K. Baldridge and
• Jay S. Siegel

Beilstein J. Org. Chem. 2024, 20, 3144–3150, doi:10.3762/bjoc.20.260

• less of an azocorannulene and more a pentaphenylpyrrole, which explains its ease of synthesis and the physical properties [21][22]. The graph with four benzene elements and a CpH core is evident in the commercially available tetrabenzofluorene, TBF (Scheme 3, lower). The parent and the phenyl TBF

• an “azacorannulene”. Working from graph structures based on chemically stable (“group elementary”) nodes is a useful principle in molecular design and chemical synthesis. Such a perspective is important to understand fundamental physical organic molecular properties as well as to predict desirable

• , however, using them in reverse. The standard uncertainty estimates of the pKa values of FIC and BFC in DMSO are 0.8 pKa units. Synthesis Material used to measure the acidity of compounds BFC and FIC was prepared previously by methods reported in reference [9]. Computational methods The structural and

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• denotes the number of individual [1.1.1]bicyclopentane (BCP) linkers – are often observed and swiftly devalorized as side-products [1]. However, targeted synthesis of functionalized [n]staffanes as rigid "molecular spacers" as proposed by Kaszynski and Michl [2][3][4] could facilitate new developments in

• synthetic challenge. Herein, we report proof-of-concept that our previous work on strain-release pentafluorosulfanylation of 1 [36] using SF5Cl (prepared in house [37] under mild oxidative fluorination conditions [38][39][40][41][42][43][44]) can be extended to the selective synthesis of the associated

• bicyclopentyl radical philicities. In addition, we demonstrate that similar reaction conditions can be applied to the synthesis of the analogous CF3SF4-containing [2]staffane (CF3SF4-BCP-BCP-Cl, 3). Finally, we examined compound 3 by SC-XRD and found that it undergoes a phase transition as a function of rate of

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• Charu Bansal Oliver Ruggles Albert C. Rowett Alastair J. J. Lennox University of Bristol, School of Chemistry, Bristol, BS8 1TS, UK 10.3762/bjoc.20.258 Abstract The chemistry of hypervalent iodine (HVI) reagents has gathered increased attention towards the synthesis of a wide range of chemical

• structures. HVI reagents are characterized by their diverse reactivity as oxidants and electrophilic reagents. In addition, they are inexpensive, non-toxic and considered to be environmentally friendly. An important application of HVI reagents is the synthesis of halogenated cyclic compounds, in particular

• this review aims to fill. The synthetic uses of HVI reagents [14][15][16], their involvement in heterocycle synthesis [17][18][19], and alkene functionalisation [20][21], have each been well-reviewed elsewhere. Review Hypervalent iodine-mediated fluorocyclisation Fluorine can substantially improve the

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• /16) aldol products with up to 82% yield in a 70:30 diastereoisomeric ratio. A decade after, Ema, Maeda and co-workers investigated using of calix[4]pyrrole macrocyclic organocatalysts for the synthesis of cyclic carbonates 21 from epoxides 20 (1,2-epoxyhexane) and CO2 [39]. For this purpose, they

• centrifugation. In the same way as a calix[4]pyrrole was used as organocatalyst for cyclic carbonate synthesis from epoxide and CO2, as discussed in section 1.1, Gallo and co-workers investigated the organocatalytic activity of porphyrin/TBACl binary catalytic systems for the regioselective cycloaddition of CO2

• necessary condition to make them organocatalytically active. Even planar porphyrin macrocycles in combination with ammonium salts can act as effective catalysts. Later in 2023, the same group reported the use of protonated H2TPP 18 as a bifunctional metal-free porphyrin catalyst for the synthesis of N

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• are found in a plethora of compounds with significant biological and pharmacological relevance [1][2][3][4]. These moieties are indispensable in the design and synthesis of novel drugs aimed at overcoming drug resistance, which is a global health threat [5][6][7]. To date, a strategy to access novel

• described (Scheme 1a–c). In 2021, Dömling’s research group synthesized a series of 1,5-disubstituted tetrazole-indoles 6 in good to excellent yields via an Ugi-azide/acidic ring-closure sequence [20]. Balalaie described an efficient method in 2018 for the synthesis of a new 1,5-disubstituted tetrazole

• previously described strategies involved the use of higher-order multicomponent reactions (HO-MCRs). As part of our ongoing research program towards the synthesis of novel hybrid compounds based on the 1,5-disubstituted tetrazole moiety [23][24][25][26][27], we developed a synthetic strategy for the

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• ; Introduction Enantioenriched α-allenic alcohols are an important class of chiral building blocks used for the chemical synthesis of biologically relevant molecules [1][2][3][4][5]. Their strength comes from the rich synthetic versatility [6][7][8][9] and biological relevance [10] of the allene functionality

• quenching with aqueous NaOH or NaHCO3 solutions. Results and Discussion Our group recently reported that N,N-diisopropylethylamine required for the synthesis of propargyltrichlorosilane isomerized it to allenyltrichlorosilane in the absence of solvents, and that removal of the amine before the distillation

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• molecular system. Herein, we present the synthesis of mono-, bis-, and tris-norbornadiene derivatives with alkynylbenzene and alkynylnaphthalene core units, along with studies of their photochemical properties. The target compounds were synthesized by Sonogashira–Hagihara coupling reactions of 2

• integration of an acetylene bridge between the arene core and the norbornadiene units in compounds 1h–n may induce these effects. Herein, we present the synthesis of these target molecules and our studies of their photochemical and physicochemical properties with a focus on energy conversion and storage

• –cycloreversion cycle of norbornadiene (1a) and quadricyclane (2a). Synthesis of alkynyl-arene-linked norbornadienes 1h–n by Sonogashira–Hagihara coupling reactions. Photoisomerization of norbornadiene derivatives 1h–l,n (20 µM) to quadricyclanes 2h–l,n in cyclohexane, m = number of norbornadienylethynyl units, n

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• morphology of the host, etc. [25]. Sequence and function metagenomic approaches have been reviewed elsewhere and will not be covered herein [26][27][28]. This Perspective focuses on chemical structure metagenomics (Figure 2c), an emerging field that integrates bioinformatics, chemical synthesis, molecular

• molecules Aside from an analysis of the BB usage pattern, real NRP-like molecules can be constructed in accordance to the predicted identity and order of the BBs. Brady and co-workers used solid-phase peptide synthesis to convert the predicted NRPs from virtual into reality; they called these molecules

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• -0083 Tokyo, Japan 10.3762/bjoc.20.252 Abstract Owing to their dynamic natures, rotaxane-based polymers are attractive motifs for developing stimuli-responsive materials. However, the accurate control of the rotaxane structure, which can be achieved via multistep synthesis, is key to utilizing the

• material. Concurrently, implementing a scale-up synthesis procedure to exploit the application potential of rotaxane-based polymers induces structural ambiguities, thereby presenting a significant trade-off between realizing inexpensive production and defined structures. To overcome this rotaxane-synthesis

• challenge, cyclodextrin (CD) can be employed as a promising alternative owing to its low production cost. Thus, this study presents an overview of the precise synthesis of CD-based rotaxane and its application to polymers to simultaneously ensure inexpensive production and realize defined structures

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• Anastasia I. Ershova Sergey V. Fedoseev Konstantin V. Lipin Mikhail Yu. Ievlev Oleg E. Nasakin Oleg V. Ershov Chuvash State University named after I.N. Ulyanov, Moskovsky pr., 15, Cheboksary, Russia 10.3762/bjoc.20.251 Abstract A facile method for the synthesis of arylidene derivatives of

• pyridine as an acceptor. The introduction of additional substituents to stilbazole makes it possible to change the optical properties of this molecular framework within a wide range [16][17][18][19]. This approach has found many applications in the synthesis of compounds that are used in various optical

• , which may be important for the manifestation of the DSE phenomenon [45][46]. Previously, we have reported the synthesis of stilbazoles A (Figure 1) [17]. In the present work, we developed a method for the synthesis of a rare class of compounds: arylidene derivatives of pyrindane 1 with conformational

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• functional groups can be functionalized for any synthetic need via HAT or β-scission with subsequent C-centered radical formation [10][11][12][13]. Also, peroxy radicals play a key role in the chemistry of the Earth's lower atmosphere [14][15][16]. The traditional approaches to organic peroxide synthesis

• pioneer studies devoted to organic peroxide synthesis using radical cascades were reported by Kharasch [24][25]. In recent decades, there has been an intensive growth of publications in this field due to the integration of traditional peroxide chemistry with modern advances in organo-, metal- and

• , phenylacetonitrile (55), with TBHP under Cu-catalysis led to a mixture of the oxidation products 56–59 including tert-butyl perbenzoate (57, Scheme 21) [25]. This discovery was later used to develop the synthesis of tert-butyl perbenzoates 61 from phenylacetonitriles 60 and TBHP (Scheme 21) [64]. The process was

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• ; perfluorinated aliphatic carboxylic acids; porphyrin synthesis; Introduction Metal porphyrins are prosthetic groups in a number of essential biomolecules, including hemoglobin, chlorophyll, and cytochromes, supporting processes such as oxygen transport, photosynthesis, and electron transfer [1][2][3][4][5

• phenyl group of the porphyrin and the perfluoroalkyl chain. The oxygen atom, especially in the 2-position, should even improve the electronic properties of the porphyrin. Results and Discussion Our synthesis started with the readily available fluorinated symmetric diols HO–CH2–(CF2)n–CH2–OH (n = 2,4,6

• ) as the aldehyde component due to its commercial availability. A OH group was introduced to serve as the nucleophile in the Williamson ether synthesis with the triflates 16, 17, and 18 (Scheme 2). Towards this end, 3,4,5-trimethoxybenzaldehyde (19) was iodinated using N-iodosuccinimide (NIS) to give

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• acceptors [13][14][15][16][17]. The Michael addition with fluorinated acceptors finds application in the synthesis of, among others, fluorinated amino acids, which can be a structural motif in many biologically active compounds [18]. There are also known studies on the incorporation of highly reactive

• our laboratory, we have explored the synthesis of 3,3,3-trifluoro- and 2,3,3,3-tetrafluoro-N-substituted propanamides, contributing to the field of fluorinated amides [25]. We have also investigated deprotonation at the α position of other fluorinated carbonyl derivatives as a route to new building

• using organolithium reagents (Scheme 1), revealing new avenues in fluorinated unsaturated amide synthesis, which are present in numerous natural products, pharmaceuticals, and polymers [34][35][36][37][38]. The obtained α,β-unsaturated amides may represent promising structural motifs for further

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• found in some natural products [34] with some fluorinated analogues [35][36], this motif is rarely found in LCs [37][38][39]. Based on these observations and literature data, we embarked in the synthesis and evaluation of enantiomerically pure acetals derived from anti-2,2-difluoro-1,3-diols as

• here preliminary results with the diastereoselective synthesis of two 4,6-diphenyl-5,5-difluoro-1,3-dioxanes (rac-3 and rac-4) and their separation into their corresponding enantiomers ((R,R)-3 and (S,S)-3; (R,R)-4 and (S,S)-4). rac-3 and rac-4 are obtained from readily available racemic 2,2-difluoro

• relationship of 4,6-diheteroaryl-5,5-difluoro-1,3-dioxanes as potential chiral dopants. The syntheses of chiral 4,6-diphenyl-5,5-difluoro-1,3-dioxanes 3 and 4 as dopants for cholesteric liquid crystals. Synthesis of rac-2 as precursor of rac-3 and rac-4. Comparison of the physical properties of enantiopures (R

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• Andrew Greener Stephen P. Argent Coby J. Clarke Miriam L. O'Duill School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK 10.3762/bjoc.20.245 Abstract Hypervalent iodine(III) reagents have become indispensable tools in organic synthesis, but gaps remain in the

• synthetic organic chemistry, becoming indispensable tools in total synthesis, late-stage functionalisation and radiolabelling [1][2][3][4][5][6][7][8][9]. Due to their great mechanistic flexibility, including reactivity as oxidants, electrophiles, radical precursors and transmetalating agents, they often

• the rational design and synthesis of novel, unstabilised hypervalent iodine(III) compounds and expand the application of these powerful reagents in organic synthesis. Results and Discussion Structural data Twelve phosphorus-iodonium ylids were synthesised (Figure 2). X-ray diffraction data (XRD) of

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• , Glasgow, G12 8QQ, UK 10.3762/bjoc.20.244 Abstract The study of organic small molecule semiconductor materials as active components of organic electronic devices continues to attract considerable attention due to the range of advantages these molecules can offer. Here, we report the synthesis of three

• properties of violanthrone is traced back to 1950, when Akamatu and Inokuchi measured its electrical conductivity (σ), which was found to be 3.4 × 10−4 Ω−1 cm−1 [27][28]. The chemical structure of violanthrone allows for its modification and hence the synthesis of materials with interesting spectral

• of our knowledge, neither OPV device fabrication nor the charge mobility of 3b has been reported. Therefore, in this work, the synthesis of compound 3b and other new analagous solution-processable derivatives are reported. The performance of these materials as the semiconductor layer in OFETs was

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• or without the use of transition metals [44]. Thus, they address both the financial and environmental challenges associated with organic synthesis by acting as environmentally benign substitutes for costly organometallic catalysts and heavy-metal-based oxidants. Diaryl iodide salts consist of two

• -arylations utilizing diaryliodonium salts, marked by significant contributions, notably from research teams led by Sanford [53] and Gaunt [54]. The synthesis of carbon–carbon bonds through metal-free approaches serves as a valuable complement to transition-metal-catalyzed couplings. This is particularly

• to achieve the fluorinated products having a tetrasubstituted benzylic carbon center in good to excellent yields. The strategy was also used for the synthesis of α-arylated α-fluoro(arylsulfonyl)acetonitriles in good yield. In a recent study, Dohi et al. achieved the arylation along with

C–H Trifluoromethylthiolation of aldehyde hydrazones

• Victor Levet,
• Balu Ramesh,
• Congyang Wang and
• Tatiana Besset

Beilstein J. Org. Chem. 2024, 20, 2883–2890, doi:10.3762/bjoc.20.242

• corresponding sulfur-containing heteroarenes, only a few methods have been developed (Scheme 1). In 1988, Lee and co-workers reported the synthesis of SR-containing hydrazones in a two-step process (chlorination [65] then reaction with thiols) from readily available aldehyde-derived hydrazones [66]. Wang et al

• . developed a method to access thiocyanated derivatives including an aldehyde hydrazone (a unique example) in 70% yield thanks to the in situ generation of SCN-succinimide from NCS and NH4SCN (Scheme 1) [67]. In the same vein, the group of Monteiro [68], then Hajra [69], independently, reported the synthesis

• of 5-thioxo-1,2,4-triazolium inner salts by the nucleophilic thiocyanation of N,N-dialkylhydrazonoyl bromides, in situ generated from aldehyde-derived hydrazones in the presence of an oxidant (NBS, (NH4)2S2O8), Scheme 1). In 2024, the synthesis of 2‑imino-1,3,4-thiadiazoles was achieved by

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• .20.241 Abstract An efficient and facile synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives was developed through the isocyanide-based multicomponent reaction of isocyanides, gem-diactivated olefins, and cyclic imines such as dibenzoxazepine, dibenzothiazepine

• diagnostic and therapeutic procedures [25] or PBOX-6 is a drug for the treatment of depression [26]. Benzothiazepines are known as antidepressants and are molecules with interesting electronic properties (Figure 1) [27]. Accordingly, the synthesis of new derivatives of pyrrole-fused benzodiazepine

• /benzoxazepine/benzothiazepine is very important. Due to the wide applications of pyrrole-fused heterocycles, very diverse approaches have been developed for their synthesis [28][29][30][31][32]. In recent years, multicomponent reactions (MCRs) have emerged as one of the most efficient and powerful methods to

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• their activity against various types of cancer. N-Glycosides of indigo, indirubin, and isoindigo, blue, red, and yellow sugars, turned out to be of special interest because of their high cancerostatic activity and structural novelty. The present article provides an account on the synthesis and

• readily available and cheap. Since then, indigo was produced in large scale. The synthesis, derivatization, and application of indigo derivatives have been widely studied [1][2][3]. Besides their application as dyes, indigo derivatives represent versatile tools for the development of innovative

• tumors PRCL PC3M and RXF 631L) with IC50 values of about 2.8 mg mL−1 and IC70 values of >3 mg mL−1. In 2005, our group developed a synthesis of indigo-N-glycosides (Scheme 3) [19]. The TMSOTf-mediated reaction of readily available N-benzylindigo (1b) with tri-O-pivaloyl-α-ʟ-rhamnosyl trichloroacetimidate

Multicomponent synthesis of α-branched amines using organozinc reagents generated from alkyl bromides

• Baptiste Leroux,
• Alexis Beaufils,
• Federico Banchini,
• Olivier Jackowski,
• Alejandro Perez-Luna,
• Fabrice Chemla,
• Marc Presset and
• Erwan Le Gall

Beilstein J. Org. Chem. 2024, 20, 2834–2839, doi:10.3762/bjoc.20.239

• primary organozinc reagents. Keywords: alkyl bromides; branched amines; Mannich reaction; multicomponent reaction; zinc; Introduction The multicomponent Mannich reaction is one of the most powerful tools available in organic synthesis for the straightforward generation of α-branched amines [1][2][3

• , we reasoned that replacing alkyl iodides by alkyl bromides could be relevant to the field due to interesting assets such as better availability and lower cost of the parent alkyl halides. Results and Discussion We investigated new conditions that would allow for the synthesis of mixed alkylzinc

Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

• Kento Iwai,
• Akari Hikasa,
• Kotaro Yoshioka,
• Shinki Tani,
• Kazuto Umezu and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

• -acylamine; oxazole; propargylamine; Introduction Propargylamine is an important motif in the synthesis of heterocyclic compounds [1][2][3][4] and drug discovery [5][6] due to its multifunctionality, which includes a basic and nucleophilic amino group, an electrophilic and dipolarophilic triple bond, and an

• amide 1b was used, the experiment was conducted in the same way. Synthesis of tricarbonylated propargylamines 4 Under argon atmosphere, a solution of ethynylbenzene (3a, 110 μL, 1.0 mmol) in THF (1 mL) was cooled to −50 °C. To this solution, a 1.6 M hexane solution of butyllithium (550 μL, 0.86 mmol

• experiments were conducted in the same way. In the deuteration experiment, the reaction was quenched with deuterium oxide (0.2 mL) instead of acetic acid. The decrease of the integral of the signal of the benzyl proton was confirmed by 1H NMR analysis. Synthesis of polyfunctionalized methane derivatives

Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• fall short in environments where multiple, overlapping signals or low concentrations are present. The emerging strategies discussed in this article aim to overcome these limitations by leveraging novel materials, advanced synthesis techniques, and cutting-edge detection mechanisms for the detection of

• in an analogous fashion to the Eu.1 complex, via a three-step synthesis as reported previously [16] and depicted in Scheme 1. The corresponding terbium(III) species was synthesized by the combination of three equivalents of the ligand L with terbium(III) trifluoromethanesulfonate under basic

• interaction is the focus of our future research studies. Experimental Synthetic materials and methods The Cu2+ ions were sourced from Cu(NO3)2·5H2O (Cat. #1027900250, Sigma-Aldrich). The synthesis of 4-(2-pyridyl)-1,2,3-triazole dipicolinic acid (L) was conducted as previously described [16]. Proton nuclear

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• (small-molecule concept) offer a distinctive advantage in the synthesis of new biologically active molecules, as they are synthetic bioisosters of purine bases. Imidazo[1,2-a]pyrimidine derivatives exhibit a wide range of pharmacological properties [4][5][6]. For example, this scaffold is a key

• , as evidenced by the following references [11][12][13][14][15] (Figure 1). The best known method for the synthesis of imidazo[1,2-a]pyrimidines is the one developed by Chichibabin [16][17][18][19], based on the reaction between 2-aminopyrimidine and α-haloketones. Despite the widespread use of imidazo

• [1,2-a]pyrimidines obtained by various modifications of this method and a number of others described in detail in the review by Goel et al. [4], literature data on the synthesis of tetrahydroimidazo[1,2-a]pyrimidines without substituents in the second and third positions remain limited. In this context