Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

• Milandip Karak,
• Cian R. Cloonan,
• Brad R. Baker,
• Rachel V. K. Cochrane and
• Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

• bacteria. Accessing this valuable cell wall precursor is important both for studying cell wall synthesis and for studying/identifying novel antimicrobial compounds. Herein, we describe optimizations to the modular chemical synthesis of lipid II and unnatural analogues. In particular, the glycosylation step

• analogues through the incorporation of alternative building blocks at different stages of synthesis. Keywords: chemical glycosylation; lipid II; peptidoglycan; polyprenyls; total synthesis; Introduction Lipid II (Figure 1) is an essential bacterial glycolipid involved in peptidoglycan biosynthesis [1]. It

• ramoplanin [2]. It is also the target for a host of other antimicrobials (mostly non-ribosomal peptides), including the tridecaptins [3], nisin [4], teixobactin [5], clovibactin [6], malacidin [7], and cilagicin [8]. Despite significant progress in the chemical synthesis of lipid II and its analogues, the

Copper-catalyzed multicomponent reaction of β-trifluoromethyl β-diazo esters enabling the synthesis of β-trifluoromethyl N,N-diacyl-β-amino esters

• Youlong Du,
• Haibo Mei,
• Ata Makarem,
• Ramin Javahershenas,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2024, 20, 212–219, doi:10.3762/bjoc.20.21

• -catalyzed conditions has been developed, which affords various unsymmetrical β-trifluoromethyl N,N-diacyl-β-amino esters in good to excellent yields. The reaction features mild conditions, a wide scope of β-amino esters and carboxylic acids, and also applicability to large-scale synthesis, thus providing an

• efficient way for the synthesis of β-trifluoromethyl β-diacylamino esters. Furthermore, this reaction represents the first example of a Mumm rearrangement of β-trifluoromethyl β-diazo esters. Keywords: β-carbonyl diazo; copper catalyst; fluoroalkyl diazo; Mumm rearrangement; unsymmetrical β-diacylamino

• organic synthesis, as they can be used as diazo intermediates or carbene precursors for the rapid construction of complex molecules along with the introduction of fluoroalkyl groups [14][15][16]. Although the reaction of trifluorodiazoethane [17][18][19][20][21][22][23][24][25][26][27] as well as α-diazo

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

• Yumei Wang,
• Guangzhu Wang,
• Yanping Zhu and
• Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

• synthesis of optically active difluoro-substituted indoline derivatives starting from the corresponding 3H-indoles by chiral phosphoric acid-catalyzed transfer hydrogenation was developed. Using Hantzsch ester as the hydrogen source under mild reaction conditions, the target products can be obtained with

• isostere of polar functional groups [5][6]. Chiral indoline is an important member of the class of nitrogen-containing heterocyclic compounds that often exhibits various pharmaceutical activities and exists in many natural products [7][8]. The enantioselective synthesis of chiral indolines has received

• great attention in organic synthesis. Various methods [9], including reductive hydrogenation [10][11], kinetic resolution [12][13][14], functionalization of indole [15], and de novo construction of chiral 2-substituted indolines, have been developed [16][17][18][19][20]. In recent years, the metal

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• dibenzodiazepinones in good yields (up to 45%; 2 steps) and much milder conditions using copper as the catalyst. The synthetic utility of this novel strategy was showcased by demonstrating a formal synthesis for the antipsychotic drug clozapine and to an anticancer triazole–DBDAP hybrid. Keywords: Buchwald–Hartwig

• review in 2018 focused on a variety of routes to these compounds [8]. The well-known Buchwald–Hartwig (B–H) and Chan–Lam (C–L) reactions have proven to be highly useful procedures that allow the step-economical synthesis of diverse biologically relevant heterocycles through C–N bond formation [9]. These

• occurs first at the amide position. This approach enabled the successful synthesis of a broad spectrum of dibenzodiazepinone units in a one-pot fashion. The synthetic utility of Laha’s approach was highlighted by preparing the corresponding dibenzodiazepinone which was further reacted with N

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• sialylation of the primary hydroxy group of the same galactose derivative 3 [54] (see Scheme 1), which eventually led to unprecedented conclusions concerning the very possibility of comparison of chemical properties of different glycosyl donors. Results Synthesis of glycosyl donor 2 Sialyl donor 2 was

• % for either observed (αD) or specific ([α]D) rotation values. The concentrations (c) of the solutions used for calculating the specific optical rotation (SR) are given in traditional polarimetric units (g/100 mL) unless otherwise explicitly stated as described previously [46]. Synthesis and

• sialylation reaction. TFA = CF3CO; ClAc = ClCH2CO. Synthesis of sialyl donor 2. SR values and types of supramers in solutions of sialyl donors 1 and 2 at different concentrations. Supporting Information Supporting Information File 3: Copies of NMR spectra for all new compounds, single crystal X-ray analysis

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• Mark Reihill Hanyue Ma Dennis Bengtsson Stefan Oscarson Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland 10.3762/bjoc.20.17 Abstract The synthesis of gram quantities of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc) and its 3’-sulfated analogue with a

• TEG-N3 spacer attached is described. The synthesis of the TF antigen comprises seven steps, from a known N-Troc-protected galactosamine donor, with an overall yield of 31%. Both the spacer (85%) and the galactose moiety (79%) were introduced using thioglycoside donors in NIS/AgOTf-promoted

• -3, TEG-N3 glycosides of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc, 1) and its 3’-O-sulfated analogue (2, Figure 1) were required on a gram scale to allow efficient synthesis of the glycodendrisomes. The TF antigen is presented on the surface of most human cancer cell types and its interaction with

Correction: Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2024, 20, 170–172, doi:10.3762/bjoc.20.16

• ; total synthesis; We noticed a number of minor errors in our original publication, including in Supporting Information File 1, that mostly concern the percent yield given for some of the precursors. In addition, there was a larger error related to the yield for the key step of the total synthesis of the

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• Polytechnique, CNRS, Institut Polytechnique de Paris, F-91128 Palaiseau, France Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, 75005 Paris, France 10.3762/bjoc.20.15 Abstract The Hock cleavage, which is compatible with tandem processes, was applied to the synthesis of 1-aryltetralines through a

• C–C bond adjacent to the hydroperoxide group (Scheme 1a). The best-known application of this reaction is the cumene process, which allows the production of millions of tons of phenol each year [2]. The reaction has also been used in an industrial synthesis of artemisinin [3]. Allylic hydroperoxides

• reaction is possible upon elimination of the resulting benzylic alcohol on D, allowing another arylation forming E [18]. This complex sequence of transformations is herein applied to the synthesis of 1-aryltetralines, analogues of cyclolignan natural products having important medicinal applications [19][20

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• , China 10.3762/bjoc.20.14 Abstract An efficient and practical method for the synthesis of C5-brominated 8-aminoquinoline amides via a copper-promoted selective bromination of 8-aminoquinoline amides with alkyl bromides was developed. The reaction proceeds smoothly in dimethyl sulfoxide (DMSO) under air

• , the synthesis of important C5-halogenated products gained particular attention since Stahl et al. reported the first chlorination example using LiCl as the halogen source [10]. Following this pioneering work, elegant strategies for the C5–H bromination of the quinoline ring employing simple inorganic

• , we have developed an efficient and practical method for the synthesis of C5-brominated 8-aminoquinoline amides in good to excellent yields via a copper-promoted selective bromination using alkyl bromides as the bromide source. This methodology is scalable, proceeds well with various aromatic and

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• optoelectronics) [1][2]. The synthesis of push–pull chromophores is often achieved through click-type reactions between electron-rich alkynes and electron-deficient alkenes, which is a reliable and atom-economical method. Diverse chromophores can be obtained via this method, depending upon the choice of alkynes

• have explored the synthesis of various push–pull chromophores, primarily via reactions between alkynes and alkenes. Several comprehensive reviews of nonplanar push–pull chromophores have since enriched the scientific literature [4][5][6]. In 2018, Michinobu and Diederich provided an exemplary overview

• addition of B(C6H5)3, which may be due to the enhancement of the dienophilic nature of the cyano group due to coordination with borane. Rotaxane synthesis Push–pull chromophores with nonplanar configurations have been reported as effective stoppering motifs for rotaxane synthesis. A rational approach

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

• Chuan Yang,
• Wei Shi,
• Jian Tian,
• Lin Guo,
• Yating Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

• radicals. This method allows the efficient synthesis of various indole derivatives without the need of photocatalysts or transition-metal catalysts. Mechanism experiments indicate that the process involves a radical chain process initiated by the homolysis of Umemoto's reagent. This straightforward method

• their biological activity and potential applications, continuous efforts have been dedicated to the synthesis of DHPI derivatives. Various synthetic strategies have been explored (Scheme 1), including transition-metal-catalyzed cross-coupling reactions [8][9][10], annulation reaction of carbenoids [11

• and at the same time improved cell membrane permeability. Therefore, it became a commonly used strategy to modify medicine candidates [22][23][24]. Based on these advantages, we envisioned a one-step synthesis of dihydropyrido[1,2-a]indolone skeletons utilizing an indole substrate and a

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• properties, so far. Therefore, we have synthesized selected benzo[c]quinolizinium derivatives and studied their DNA-binding and DNA-photodamaging properties. Results and Discussion Synthesis The styrylpyridine derivatives 2a,c,d,f were synthesized by a piperidine- or Ca(OTf)2-catalyzed condensation reaction

• photoreactor or in a cuvette. Photoreactions for the investigation of the DNA damage were performed with a Rayonet (RPR-100) photoreactor equipped with 12 ultraviolet lamps (8 W, λexc = 366 nm). Synthesis General procedure (GP) A solution of the styrylpyridine derivatives (c = 0.24–0.95 mM) in MeCN or in a

• ) in Na phosphate buffer, cNa+ = 16 mM. Blue: spectrum of the starting material before irradiation; red: spectrum at the end of the irradiation. Photoinduced formation of benzo[c]quinolizinium and its interaction with DNA upon intercalation. Synthesis of styrylpyridine derivatives 2a–g. Conditions: i

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• around an internal concentrically fitted draft tube, and are widely used in industry, such as microbiology fermentation and Fischer–Tropsch synthesis [21][22]. This type of reactors provides very high mass transfer rates, well-defined fluid flow patterns, and a simple design [23][24]. The construction

• get the corresponding photon flux in the reactor. Depending on the electrical current used for the experiment, the irradiation time was in a range of 1–10 min (conversion between 1 and 13%). From the conversion, the incident photon flux was calculated. Photocatalyst synthesis and characterization For

• the synthesis of the photocatalyst, melamine (99%, Sigma-Aldrich), H2PtCl6·6H2O (with a minimum Pt content of 37.50%, Sigma-Aldrich), and methanol (99.9%, VWR) were utilized. The heptazine-based polymeric carbon nitride (PCN) was synthesized by thermally condensing 30 g of melamine at 550 °C for 4 h

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• other end of the IF core with electron-accepting moieties. An overview of general motifs targeted in this work is shown in Figure 1. Results and Discussion Synthesis The synthetic building blocks 1–8 used in this work are shown in Figure 2. The dione 1 and the ketones 4 and 6 were synthesized according

• synthesis of compound 23 (Scheme 4). A compound that may tentatively be assigned to 28 was observed by MALDI–MS analysis of the reaction mixture, but less than needed for an NMR sample was isolated. Furthermore, the isolated compound proved quite insoluble in all investigated deuterated solvents, and

• ]. The data for the compounds have been deposited with the Cambridge Crystallographic Data Centre [39]. The CIF files (Supporting Information Files 2–4) and reports were generated using FinalCIF [40]. Synthesis Compounds 1 [19], 2 [21], 3 [21], 4 [14], and 6 [20] were synthesized according to literature

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• candidates as well. Ortho-hydroxy-substituted phosphines have been mainly used as chelating ligands for metal complexes until recently [16][17][18]. Further, ortho-hydroxy phosphines have been used for the synthesis of probes in metabolic labeling [19], as a photocatalyst in the defluoroalkylation of

• synthesis of carbonates from CO2 [24][25][26] and the synthesis of oxazolidines from isocyanates and epoxides [27]. Furthermore, their application in primary hydroxy group selective acylation of diols [28] and their use as organophotoredox catalysts [29][30] is known. The latter mentioned catalysts are

• -carbonyl-based Michael acceptors. Results and Discussion Synthesis During our endeavors to identify potent Lewis-base catalysts for the oxa-Michael reaction [13][14], the triarylphosphine 1 was tested in a model reaction (2 equiv allyl alcohol, 1 equiv acrylonitrile, 0.05 equiv 1). However, no conversion

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• both their biological and material applications, but so far has mainly relied on covalent modifications or amphiphiles featuring ionic side-chains. Here, we report a facile 2–4-step synthesis of pyridinium-based, bent aromatic amphiphiles with modular nonionic side-chains (i.e., CH3 and CH2CH2(OCH2CH2

• solubilized by PA-R in water and subsequently deposited onto a cellulose filter using a simple filtration protocol. Results and Discussion Synthesis of pyridinium-based amphiphiles Synthesis of the pyridinium-based amphiphiles PA-R was achieved in 2–4 steps starting from commercially available 3,5

• -dibromopyridine. Negishi cross-coupling with 9-anthrylzinc chloride in the presence of PdCl2(PhCN)2/P(t-Bu)3 as catalyst afforded the common precursor 3,5-dianthrylpyridine (prePA), a simple yet novel bent building block, in 81% yield. For the synthesis of the methyl derivative, prePA was N-alkylated with excess

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• (practical laboratory classes including examples of synthesis and compound characterization), NMRium provides a full 1D FT workflow and therefore an ideal possibility to introduce basic concepts of data processing, data presentation, and data evaluation. Spectra from most NMR instruments may be directly used

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• and Molecules, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium 10.3762/bjoc.20.3 Abstract A novel and efficient base-catalyzed, transition-metal-free method for the synthesis of diheterocyclic compounds connected by an amidine linker, including apart from the common

• synthesis of various nitrogen-containing heterocyclic compounds and have a variety of biological activities [1][2][3][4]. After the discovery of click chemistry [5][6] involving the CuAAC method of 1,2,3-triazole synthesis [7][8], there has been great interest of studing the chemical and biological

• properties of the triazoles thus obtained [9][10][11][12]. It should be noted that the synthesis of amidines containing other heterocycles in addition to 1,2,3-triazole in the molecule has not been described in the literature. In this regard, it is of interest to develop an effective method for the synthesis

Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• of two equivalents of halogen salt waste. Their substitution with iodolium salts will be more sustainable since it reduces these unproductive halogenide salts by half. Due to our recent activity in the field of synthesis and applications of 5- and 6-membered cyclic iodonium salts, we searched for an

• diaryliodonium salts [29][31], as well as Pd-catalysed methods for synthesizing N-aryl carbazoles [32]. Similar procedures were published for the Cu-catalysed synthesis of aryl carbazoles from amines as well as other heterocycles such as N-acyl acridanes with nitriles using cyclic iodonium salts by Wen and Chen

• [33][34]. Results and Discussion Initially, we investigated the synthesis of N-acyl carbazole by treatment of diaryliodonium salt 1a with valeramide using Cu(I) catalysts [18]. The results are shown in Table 1. In the first experiments in p-xylene at 120 °C with DMEDA as N,N-ligand, only modest

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• synthesis (AvaH and AvaI homologs), (ii) genes encoding a KS-CLF complex (AvaA4 and AvaA5 homologs), and (iii) a gene encoding a diazotase (AvaA6 homolog). As a result, we discovered 134 BGCs and analyzed them using antiSMASH [17] and BiG-SCAPE (Figures S1 and S2 in Supporting Information File 1) [18

• by co-expressing with the sfp gene to obtain the holo-form of CmaA3 [21]. We tested whether CmaA1 and holo-CmaA3 are involved in the initial reaction in polyketide synthesis similar to AvaA1 and AvaA3; AvaA1 loads 3,4-AHBA (1) onto holo-AvaA3 using ATP in the biosynthetic pathway of avenalumic acid

• -coumaric acid synthesis. Therefore, it is interesting to understand why actinomycetes synthesize p-coumaric acid using such a specialized biosynthetic pathway including diazotization and denitrification. It should be noted that only three ammonia-lyases for p-coumaric acid biosynthesis have been

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• the aldol condensation products. Importantly, the ability to recycle the ionic liquid in subsequent reactions was successfully demonstrated. Keywords: alkyne hydration; boron trifluoride; electrochemical synthesis; ionic liquids; Introduction Alkynes are fundamental starting materials towards more

• 1881, Kucherov identified mercury(II) salts in sulfuric acid as efficient promoters of the hydration of alkynes and this catalyst system has found applications in industrial scale synthesis [10]. However, the toxicity and the environmental issues associated with the use of mercury-based compounds have

• weakly coordinating or not-coordinating organic or inorganic anions. They have interesting physicochemical properties that differentiate them from the organic solvents commonly used in synthesis [74][75][76][77]. Importantly, they have a very low vapour pressure, and therefore do not behave as air

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• ligation from shorter 20 to 60 nt ODNs produced by automated de novo chemical synthesis. While these methods have made many projects in areas such as synthetic biology and protein engineering possible, they have various drawbacks. For example, they cannot produce genes and genomes with long repeats and

• have difficulty to produce sequences containing stable secondary structures. Here, we report a direct de novo chemical synthesis of 400 nt ODNs, and their isolation from the complex reaction mixture using the catching-by-polymerization (CBP) method. To determine the authenticity of the ODNs, 399 and

• 401 nt ODNs were synthesized and purified with CBP. The two were joined together using Gibson assembly to give the 800 nt green fluorescent protein (GFP) gene construct. The sequence of the construct was verified via Sanger sequencing. To demonstrate the potential use of the long ODN synthesis method

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• CACTUS, Campus Vida, 15782 Santiago de Compostela, Spain 10.3762/bjoc.19.145 Abstract The synthesis of zwitterionic dithiocarboxylate adducts was achieved by deprotonating various aldiminium or 1,2,3-triazolium salts with a strong base, followed by the nucleophilic addition of the in situ-generated

• -dithiocarboxylate zwitterions (Figure 2) [30][31][32][33][34][35][36][37][38][39][40][41][42][43]. These 1,1-dithiolate inner salts strongly bind main group elements and transition metals through various coordination modes. Indeed, we and others have already reported the synthesis of diverse metallic complexes

• (−)-menthone was obtained in a separate step by deprotonating the corresponding aldiminium triflate with lithium diisopropylamide (LDA) at −78 °C [8]. Herein, we disclose the synthesis of three CAAC·CS2 and six MIC·CS2 inner salts from the corresponding aldiminium or 1,2,3-triazolium salts and carbon disulfide

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• the synthesis of spirooxindole derivatives continues to be a highly active subject in organic synthesis [31][32][33][34][35]. In recent years, the readily available isatin-derived Morita–Baylis–Hillman (MBH) carbonates have become one of the most powerful reagents for the construction of diverse

• efficient synthesis of spiro[azepine-4,3'-indoline] derivatives via the [4 + 3] cycloaddition reaction of bromo-substituted isatin-derived MBH adducts and N-(o-chloromethyl)arylamides. In this efficient protocol, the reactive allylic phosphonium ylides and aza-o-quinone methides were generated in situ and

• -derived MBH carbonates with α-halogenated N-acylhydrazones for the convenient synthesis of functionalized spiro[indoline-3,5'-[1,2]diazepine] derivatives (reaction 5 in Scheme 1). Results and Discussion Initially, the reaction conditions were screened by employing α-chloro-N-benzoylhydrazone 1a and MBH

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• ; reduction; reductive dimerization; Introduction Reductive dehalogenation reactions of organic halides can be used in organic synthesis as a means of generating carbon-centered radical or anion intermediates and could have relevance to the treatment of waste halogenated polymers. While such reactions can be

• achieved using highly reducing metals, molecular reductants can potentially enable more selectivity, as required for the use of such reactions in the synthesis of molecules bearing various functional groups. In particular, Wanzlick dimers (C=C-bonded dimers of N-heterocyclic carbenes, Figure 1a, i) have

• bibenzyls being the dominant products. These reaction conditions represent an alternative metal-free approach to the conventional synthesis of bibenzyls through the reaction of Grignard or organolithium reagents with benzyl halides, or to the use of highly active metal reagents [33][34][35][36] or metal