Synthesis and characterization of water-soluble C₆₀–peptide conjugates

• Yue Ma,
• Lorenzo Persi and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71

• -Lys (5a) was recorded in D2O. As shown in Figure 5, the spectrum of 5a (upper spectrum) clearly shows peaks for protons corresponding to the fulleropyrrolidine part, which are in line with the peaks in the spectrum of the C60 Prato monoadduct (lower spectrum), linker part, and oligo-Lys side chain

• , and HMBC spectra (Figures S3–S9, Supporting Information File 1), all peaks corresponding to the pyrrolidine part, linker part, and oligo-Lys part were assigned as shown in the chemical structure. In the sp2 region of 5a (Figure 6a, top), 17 signals (1C × 3 + 2C × 13) were observed similarly to the

Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• tetrapyrrole compounds [9] since the delivery of a drug at a specific area in the body has vital importance to treat diseases. An alternative approach to solve this problem focused on the postfunctionalization of the porphyrin macrocycle with different linker groups capable for targeting conjugation of these

• conjugates with functionalized linker groups suitable for bioconjugation or which may be efficient for PDT and BNCT improvement. Results and Discussion Synthesis Nucleophilic substitution reactions of the four p-fluorine atoms in 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (1) are well studied [15][16

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• biomimetic linker to imitate peptide-S-PCP [46], which not only employed in the efficient cyclization of tyrocidine A (1) but also worked on hundreds of other linear substrates, some of which exhibited broad-spectrum activity against both Gram-positive and Gram-negative organisms. By combining natural

• exhibits a cyclization activity against a peptide methyl ester that is feeble but readily detectable [61]. This finding indicates that SurE has a high tolerance for leaving groups. In the light of this property, Wakimoto, Matsuda, and co-workers discovered that ethylene glycol (EG) can act as a linker on

• manner catalyzed by homolog WolJ [63] and SurE G235L (Scheme 5b). Additionally, the above mentioned type I TE, TycC TE, can also tolerate ethylene glycol as a leaving group and gave tyrocidine A (1) in 70% yield, indicating that this convenient bifunctional linker may have a comparable applied range to N

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• effect remains if the local structure of the linker consisting of an alkyl group and a pyrene group is maintained. Therefore, it is likely that the kinetic behavior of a protein immobilized with a single PASE linker exhibits an activation barrier-type energy surface between the bi-stable conformations on

• of molecules based on nanoscience can lead to a better understanding of the behavior of target biomaterials and improve the sensitivity of specific dynamical systems, such as biosensors. In this study, we investigate the behavior of proteins immobilized with linker molecules on graphene substrates

• . It is known that graphene may not easily adsorb proteins [1]. On the other hand, proteins can be immobilized on graphene by using appropriate linker molecules, such as 1-pyrenebutanoic acid succinimidyl ester (PASE). Actually, pyrene and its derivatives have been demonstrated to form stable bindings

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells

• Fumihiro Ishikawa,
• Sho Konno,
• Hideaki Kakeya and
• Genzoh Tanabe

Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39

• introduced a pegylated biotin linker at the 2′-OH group of ʟ-Phe-AMS and confirmed that the probe retains the binding activities toward the A-domain of GrsA, a gramicidin S synthetase. Aldrich et al. developed a Sal-AMS-based activity-based probe (ABP) to profile MbtA in M. tuberculosis [12]. In contrast, we

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• of Fe3O4 nanoparticles (Scheme 15) [101][102]. This organic–inorganic hybrid material was synthesized by the immobilization of the dodecatungstovanadophosphoric acid (HPA) on TPI-Fe3O4 with N-[3-(triethoxysilyl)propyl]isonicotinamide (TPI), acting as the linker for the heterogeneous catalyst, while

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

• to analyse when data were recorded in CDCl3. Changing the NMR solvent to CD3OD greatly reduced the complexity of the spectra [21][22][23]. Since 7 possessed an azido group as part of the linker, removal of the Troc group under reductive conditions was ruled out due to probable chemoselectivity issues

• sulfated 2 (Figure 2). This showed that regioselective 3’-O-sulfation had been achieved, with HRMS also indicating that only one sulfate group was present. Conclusion An efficient synthesis of the important TF and 3’-Su-TF antigens equipped with a TEG-N3 linker to allow formation of various conjugates has

• (td, J = 10.6, 3.6 Hz, 1H, H-2), 4.26 (dd, J = 12.6, 2.2 Hz, 1H, H-6(A)), 4.15 (dd, J = 12.5, 1.7 Hz, 1H, H-6(B)), 3.90–3.77 (m, 2H, H-5, CH2(A)Linker), 3.76–3.59 (m, 9H, CH2(B)Linker, 4 × CH2(Linker)), 3.39 (t, J = 5.1 Hz, 2H, CH2(Linker)), 2.07 (s, 3H, CH3(OAc)), 1.08 (s, 9H, C(CH3)3(DTBS)), 1.02 (s

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

• comprising pyrimidine and 1,2,3-triazole rings connected with an amidine linker by the cycloaddition reaction of 3,3-diaminoacrylonitriles with 6-azidopyrimidine (Scheme 1C). Based on this idea, an efficient and novel method with wide scope has been developed which was then applied to obtain a variety of

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• triphenylamine as donor and dimesitylboron as acceptor linked through a thieno[3,2-b]thiophene (TT) π-conjugated linker bearing a 4-MeOPh group, was designed, synthesized, and fabricated as an emitter via a solution process for an organic light-emitting diode (OLED) application. DMB-TT-TPA (8) exhibited

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• diazocarbonyl reagent is presented for the first time. The protective group is removed without acid catalysis with near quantitative yields. New benzotriazole derivatives containing functional groups capable of participating in the subsequent modification for linker attachment to assemble the PROTAC molecule

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• homogeneous reaction. For example, by incorporating a lipophilic side chain [28] on the organocatalyst that does not interfere with its catalytic activity thanks to a linker between the catalyst and lipophilic units. In this way, a significant difference in polarity can be achieved between the catalyst and

• this catalyst easily by incorporating a lipophilic unit, which leads to a drastic increase (5.78 to 28.8) in the logP value of the organocatalyst 2. The recyclable organocatalyst can be divided into three units: the catalytic unit, the linker, and the lipophilic tag with octadecyl chains (Figure 1

• ). The cinchona amine 3 was prepared starting from the naturally occurring quinine [31]. The gained catalyst was demethylated using BBr3 to give alcohol 4. The demethylated cinchona amine was reacted with half-squaramide [9] 5, resulting in demethylated squaramide 6. A short and flexible linker was

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• differentiation of the triplets at δ = 4.18 ppm and δ = 3.78 ppm corresponding to CH2 protons from the pentyl linker, also confirmed by H,H-COSY NMR. Comparison of the 1H NMR spectra of R2 and its components 6 and M2 revealed substantial differences in the chemical shifts of different signals of R1 and 6, M2

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• study raises a concern regarding the performance of dyes with tert-butyl substituted DPQ acceptors, either containing benzene (Qx74) or thiophene (Qx75) as a π-conjugation linker and their benzotriazole analogue. While the incorporation of the Qx enhances the interaction between the donor and acceptor

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• supramolecular architectures [45], e.g., catenanes [73], rotaxanes [74], and catalytic systems [75]. Pelegrino and co-workers reported on crowned porphyrinoids demonstrating interesting photophysical properties [71]. The crown ether part was also demonstrated to play a role of a linker between two porphyrin

• ]. The latter incorporated two dipyrromethane/dipyrromethene units connected through iminoalkyl bridges. The architecture of the macrocycles, and their anticipated dynamic behaviour, wherein two dipyrromethene parts can come closer or further due to the flexibility of the alkyl linker, is reminiscent to

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• these results [37][38]. For several years, our group was interested in preparing multivalent carbohydrate mimetics [39][40][41][42][43] on the basis of efficient coupling reactions of aminopyran and aminooxepane derivatives with suitable linker elements. Hence, the aminopyran derivatives A could be

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• glycan sequences. We showed that, while loading and reaction scale did not significantly influence the AGA outcome, the chemical nature of the linker dramatically altered the isolated yields. We identified that the major determinants of AGA yields are cleavage from the solid support and post-AGA

• purification steps. Keywords: automated glycan assembly; photocleavable linker; polysaccharides; solid-phase synthesis; Introduction Automated glycan assembly (AGA) is a solid-phase method that enables the rapid synthesis of complex oligo- and polysaccharides from protected monosaccharide building blocks

• scale [19], and linkers [20][21] affect the overall yield of solid phase peptide synthesis (SPPS). In the past decades, several supports and linkers have been developed and commercialized for SPPS, enabling a wide range of applications. Solid supports are available with different linker loadings, with

Facile access to 3-sulfonylquinolines via Knoevenagel condensation/aza-Wittig reaction cascade involving ortho-azidobenzaldehydes and β-ketosulfonamides and sulfones

• Ksenia Malkova,
• Andrey Bubyrev,
• Stanislav Kalinin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 800–807, doi:10.3762/bjoc.19.60

• linker or pharmacophore group. In fact, more than one hundred FDA-approved drugs are sulfonamide-bearing small molecules. Screening libraries of aromatic and heteroaromatic sulfonamides gave rise to the discovery of multiple physiologically active compounds [27][28][29][30] including important

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• or HBC-like units into one ring system is a straightforward way to generate HBC-based chiral NGs. In general, different HBC units were fused together to form the final chiral structures by connecting with a linker or sharing the same phenyl ring. As shown in Scheme 5, Jux and co-workers synthesized

• the NG precursor 39 by heating dialkyne 38 and tetracyclone 2, which led to two hexarylbenzene units connected by an oxygen linker. Upon treatment of 39 under Scholl reaction conditions (DDQ, TfOH), an oxa-[7]helicene containing chiral NG 40 was obtained in high yield [43]. Meanwhile, they enlarged

• -workers synthesized a helical bilayer NG by using helicene in the initial step as the linker to fuse two HBC units [48]. As shown in Scheme 6, starting from the helical alkyne 54, Sonogashira coupling with 4-tert-butyliodobenzene (55) afforded structure 56 in a 77% yield. Subsequent Diels–Alder reaction

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• 7a–t in 28–72% yield (Scheme 4, Table 1). Having obtained several new compounds containing substituted imidazo[1,2-a]pyridine and peptidomimetic fragments linked by a CH2O linker, we further explored the possibility of synthesizing similar hybrids without a CH2O linker between the two moieties. The

• imidazo[1,2-a]pyridine and peptidomimetic fragments it is better to use acids with a linker between the carboxyl group and aryl ring. This molecular fragment increases the solubility of the whole molecule, which leads to an improvement in the reactivity of the acids, whereas the reactivity of acids 8a and

• manner. A method for the synthesis of the desired compounds was developed, and a small library of 20 Ugi products was prepared. The study also demonstrated that the use of a CH2O linker between the carboxyl group and the aryl ring in the Ugi reaction enhanced the reactivity of the acid component. The

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• ) by alkylation of 1a was patented in 1997 [79]. The process involves the alkylation of iminostilbene (1a) as a critical intermediate step (Scheme 33C). The alkyl halide linker of 148 was further functionalised by reaction with piperazine derivative 149 to give opipramol (5). 6.2 C-Functionalisation

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• of the etheric oxygen atom and the antibonding orbital of the P=O bond (the stereoelectronic effect), leading to the more stable anti-diastereomer 74 (Scheme 16) [38]. In the phostone 74 was installed a linker 2-(5-aminopentoxy) group via transesterification with benzyl N-(5-hydroxypentyl)carbamate

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• -conjugation of 1,8-bis(dimethylamino)naphthalene (DMAN) fragments through a butadiyne linker and a donor–acceptor aryl–C≡C–DMAN conjugation path. The conjugation path can be “switched” simply by protonation of DMAN fragments. X-ray diffraction, UV–vis spectroscopy and cyclic voltammetry are applied to analyze

• which although conjugated to a third unsaturated center are not conjugated to each other” [16]. It is easy to see that there are two π-conjugation paths in molecules 5: a donor–acceptor conjugation path (Figure 2, highlighted in blue) and the π-conjugation of naphthalene rings through a butadiyne linker

• averaged planes of the naphthalene rings, ∠Cx‒Cy–Cz is the bond angle of the carbon–carbon bonds in the butadiyne linker, Θ is the C2(2′)–C3(3′)–C6(6′)–C7(7′) torsion, N···N is the internitrogen distance in the DMAN fragments, Σ∠N is the sum of the C–N–C angles of the NMe2 groups, and φ is the N1(1′)–C1(1

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• )) and includes a chiral auxiliary, an amino acid, and a bifunctional linker capable to arrange the components in the Schiff base complex. Such templates provide a significant C–H acidity at the α-amino acid carbon and a possibility for recycling of the chiral auxiliaries (for reviews see [5][14][15][16