Chemical glycobiology

• Elisa Fadda,
• Rachel Hevey,
• Benjamin Schumann and
• Ulrika Westerlind

Beilstein J. Org. Chem. 2025, 21, 8–9, doi:10.3762/bjoc.21.2

• glycan assembly [9]. Target-directed synthetic strategies are being developed by Reihill et al. [10] and Karak et al. [11], exploring the syntheses of the linker-displaying, sulfated TF disaccharide and lipid II analogues, respectively. The direct application of synthetic glycans is shown by Fan et al

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

• Merve Yence,
• Dilgam Ahmadli,
• Damla Surmeli,
• Umut Mert Karacaoğlu,
• Sujit Pal and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

• %). This cascade involves an initial Suzuki–Miyaura cross-coupling reaction between 1,8-dihalonaphthalenes and heteroarylboronic acids or esters, followed by an intramolecular C–H arylation under the same conditions to yield the final heterocyclic fluoranthene analogues. The method was further employed to

• heteroatoms or other heterocycles to obtain heterocyclic fluoranthene analogues offers numerous opportunities for structural and functional diversifications. For instance, azafluoranthenes such as triclisine (1) or imeluteine (2) constitute a common structural motif encountered in natural products isolated

• ) ligand 4 were reported by Cowley and co-workers in 2010 [14]. In addition to heterocyclic fluoranthene analogues, highly oxygenated benzo[j]fluoranthenes are commonly encountered fungal natural products with important biological activities [15]. Bulgarein (5) is an example of such a benzo[j]fluoranthene

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• activity against both Pseudomonas aeruginosa and Staphylococcus aureus, has contributed to a surge in the interest of polyamines as new antibacterial leads [6]. To date the total synthesis of ianthelliformisamines A–C (1–3) has been described [7] and numerous synthetically related analogues have been

• new leads against Pseudomonas aeruginosa and supported by numerous reports of favourable activity for ianthelliformisamines A–C [7][12] and their synthetic analogues [8][9][10], we investigated the planktonic and biofilm activity of the new natural products 4–7 in addition to the known metabolite

• , aplysterol (8) [13]. Our biological assessment of compounds 4–8 showed no inhibition of planktonic growth or biofilm formation for P. aeruginosa when screened at 50 µM. Previously reported antibacterial assessment of ianthelliformisamines A–C (1–3) and their synthetic analogues has generated structure

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• feature results will be further confirmed by the insertion of these cyclic β-dehydropiperazic acids in longer peptide sequences. Examples of bioactive tetrahydropyridazine derivatives. Linear and cyclic peptides incorporating the dehydropiperazic acid moiety. Piperazic acid and analogues and target

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

• free-base) macrocycles have not been explored as much in terms of catalysis, even though they are starting compounds for the preparation of their metallated analogues that are commonly used as catalysts. In contrast with a calix[4]pyrrole macrocycle with four NHs (from four pyrrole units), a metal-free

• one remaining –NH group is catalytically active while both tri- and tetraalkylated analogues 40 and 41, without an –NH unit, are not. Further, the authors performed 1H NMR experiments with a different substrate:macrocycle ratio and suggested a bifunctional reaction mechanism involving both inner amine

• ones with secondary amine side arm (48d, 48g, h) were catalytically active for Michael additions, providing 60–71% yields (Table 3), whereas tetraalkylated analogues (49a–g) and dialkylated OxPs without a secondary amine side arm (48a–c, 48e and 48i) were not. Based on these results, the authors have

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

• and the analogues 1c and 1e without an alkyne linker [29][30][34]. As the only exception, the m-substituted derivative 1k has a higher quantum yield than its analog 1b, which is, however, still lower than the one of the cyano-substituted norbornadiene 1c [30][34]. In addition, substitution at the 2

• quadricyclanes from 3.0 h to 7.8 h, which are essentially in the same range as the ones of analogues with an acceptor-substituent in the 3-position of the norbornadiene [34]. Notably, the quadricyclane derivatives with sterically more demanding substituents in the 2-position of the norbornadiene unit, such as 1e

• , showed longer half-lives. Therefore, compounds 1h–l,n have significanty lower half-lives than the corresponding analogues without an alkyne linker [29][30]. Conclusion In summary, a small series of mono-, bis-, and tris-norbornadiene derivatives with alkynylbenzene and alkynylnaphthalene core units was

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

• dimethylene bridge in arylidene derivatives of pyrindane 1 led to an increase in the emission quantum yield and caused an appearance of solid-state photoluminescence, in contrast to the previously synthesized analogues (stilbazoles A, Figure 1) without such a bridge (Tables S3 and S4, Supporting Information

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

• two achiral nematic host mixtures (Host 1 and Host 2 from Merck) (Table 1). (R,R)-3 and (S,S)-3 with a more liquid crystal-like shape have higher HTP [16 µm−1 (Host 1), 38 µm−1 (Host 2)] than the dimethylacetal analogues (R,R)-4 and (S,S)-4 [8 µm−1 (Host 1), 15 µm−1 (Host 2)]. The difference between

• the two nematic host mixtures is their polarity: whereas Host 1 is only moderately polar (Δε = 4.0), the mixture Host 2 was developed for Blue Mode LCD application and is extremely polar. As compared to chiral dopants depicted in Figure 1, HTPs are lower and closest analogues for comparison could be

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

• containing the sugar moiety attached to the amine-type nitrogen are less stable than the corresponding compounds containing the sugar moiety attached to the amide-type nitrogen atom. Unfortunately, the synthesis of β-31a was not a general method for the synthesis of indirubin-N-glycosides. Analogues of

• stirred for 6 h at 20 °C to give E-β-46a. Likewise, rhamnosides E-β-46b–e, mannosides E-β-46f–i, glucosides E-β-46j,k, and galactosides E-β-46l,m were prepared. 3-Alkylideneoxindole-N-glycososides 46 can be regarded as analogues of indirubin-N-glycosides completely missing the nitrogen atom of the indoxyl

• deprotection with NaOMe afforded β-81a in 98% yield. Likewise, rhamnosides β-81b,c mannosides β-81d–f, and glucoside β-80g were obtained in good yields. Some products exhibited weak cytotoxic activity against human ceratinocytes (HaCaT). However, in contrast to many indirubin-N-glycosides and their analogues

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

• are highly selective to HS−(aq) ions and are thus suitable for environmental or biological studies where interfering anions may be present. Gaseous H2S studies of [Tb.1·3Cu]3+ We aimed to further investigate the luminescence response of Tb3+ analogues upon exposure to hydrogen sulfide gas, building

• upon our previously reported findings. Our earlier work demonstrated an increase in europium luminescence with a LoD of 100 ppb and 665 ppb for two Eu analogues [Eu(triazole-DPA)3·3Cu]3+ [16] and [Eu(DO2A)DPA·Cu]+ [17], while the [Tb(DO2A)DPA·Cu]+ analogue [17] exhibited no significant change in

• emission spectrum, unlike that observed with the europium(III) analogue. This result suggests potential variations in the luminescence response among terbium(III) analogues and highlights the complexity of the interaction between lanthanide complexes and gaseous H2S, and understanding the nuances of this

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• . Functionalization at the meso-phenyls’ ortho- position was not manageable and more research is needed to optimize conditions. Comparing the yields in coupling of borylated porphyrins and the halogenated analogues revealed a greater yield, when the polarity of the reaction was reversed; however, due to tedious

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• -dihydro-1H-pyrroles using aryldiazonium salts and (S)-PyraBox, followed by sequential Jones oxidation. They showcased their methodology by preparing both (R)-rolipram and (R)-baclofen hydrochloride. Tóth et al. reported the design and synthesis of new analogues of HeE1-2Tyr, a nonnucleoside SARS-CoV-2

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• increases, and techniques develop at a rapid pace [10][11][52][53]. SAS techniques include small angle X-ray scattering (SAXS), small angle neutron scattering (SANS), and their wide angle (WAXS) and ultra-small angle (USAXS and USANS, respectively) analogues have various advantages and drawbacks compared to

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• triacetoxylates, including the LSF of bioactive compound analogues (Scheme 50). The mechanism involves the photoexcitation of TAC+, which facilitates the selective oxidation of C–H bonds in alkylarenes. This process efficiently forms multiple C–O bonds while minimizing the risk of overoxidation. The versatility

• and mildness of this method were demonstrated by successfully applying it to various substrates, including bioactive compound analogues. This advancement highlights the potential of electrophotocatalysis in achieving complex transformations in organic synthesis, particularly in the selective

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• Olivier Lessard Mathilde Grosset-Magagne Paul A. Johnson Denis Giguere Département de Chimie, 1045 av. De la Médecine, Université Laval, Québec City, Qc, G1V 0A6, PROTEO, Canada 10.3762/bjoc.20.208 Abstract In this work, we describe the synthesis of halogenated pyran analogues of ᴅ-talose using a

• halo-divergent strategy from known 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-ᴅ-mannopyranose. In solution and in the solid-state, all analogues adopt standard 4C1-like conformations despite 1,3-diaxial repulsion between the F2 and the C4 halogen. Moreover, the solid-state conformational analysis of

• and nonbonding interactions for the halogen at C4. Finally, density functional theory (DFT) calculations corroborate the preference of talose analogues to adopt a 4C1-like conformation and a natural bonding orbital (NBO) analysis demonstrates the effects of hyperconjugation from C–F antibonding

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• . The limitations in the scope of this methodology include a poor stereoselectivity achieved with 5-membered cyclic 2,3-disubstituted silanes in contrast to the 6-membered analogues (53). A lower efficiency was recorded with 2-substituted allylsilanes bearing either a halogen or an alkyl group with

• analogues, a novel tetrakis-triazole-based H-bond donor catalyst 111 was identified as most promising. Among different nucleophilic allylating reagents, 2-methallyltributyltin (107) emerged as optimal in terms of reactivity and enantioselectivity. It was speculated that the enantioinduction is realised via

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• Information File 1 for details) [43]. As expected, amides 5 also undergo tandem diazotization/azo coupling reaction to form the target [1,2,5]oxadiazolo[3,4-d][1,2,3]triazin-7(6H)-ones 7. It should also be noted, that compounds 7 were obtained in similar yields as the corresponding furoxan analogues

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• a probe either directly in living cells or in cell lysates utilizes a linker with biotin (Figure 8A). This approach led for example to the identification of protein targets of the synthetic pyrethrin analogues cerulenin, hypothemicin, fimbrolide, and eupalmerin acetate [89][90][91][92]. The biotin

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• plethora of hetero-analogues of both truxene and isotruxene have been reported with altered physiochemical properties [30][34][35]. To our best knowledge, derivatizations of the truxene core with heterocycles are limited [33][36][37][38] and needs to be explored for diverse promising applications. Keeping

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• -alkyl/aryl-substituted analogues, and aldehyde component switch to heteroaromatic (2-pyridinaldehyde) and aliphatic (iPrCHO, cinnamaldehyde). Unfortunately, we failed in both replacements and were unable to obtain any reasonable products. The list of unsuccessful reagents is shown in Figure S7 (see

• ]. We hope that compound 2r and its analogues obtained in this work can be further deeply studied by in silico and in vitro methods to discover the compound most suitable for clinical trials. The structures of the synthesized compounds 2a–r were confirmed by spectral data. The 1H NMR spectra of the

Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles

• Ivan Lyutin,
• Vasilisa Krivovicheva,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164

• (azetidin-2-one) scaffold to medicinal chemistry and drug design is self-evident. This four-membered heterocycle is a key fragment of many antibiotics [1], including penicillin and its analogues, as well as other pharmacologically important molecules [2]. Therefore, the search for new efficient and

• . It can be observed that the 5-monosubstituted diazo derivatives, and especially those with no substituents in position 5, form the target products in lower, often moderate yields (see products 3i,j,n and 3r,s,t) compared to the 5,5-disubstituted (spirocyclic) analogues. This result may be related to

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• better inhibitory data than for the aforementioned furyl analogues (Scheme 4). The authors suggested the replacement of furyl by a more polarizable aromatic ring such as thienyl as prospective origin of the observed IC50 downward shift. Berthelot et al. [23][24] expanded their studies on GABAB inhibitors

• of this aromatic ring. Molecular docking studies combined with in vitro studies showed that only the thiophene-based phenethylamine derivative 30 possesses a weak hCA I/II activity compared with analogues lacking the 2-aminoethyl moiety. Carrol et al. [31][32] explored bupropion analogues for their

• approximately 15-fold more active than histamine (Scheme 9). Gannellin et al. [51] performed a discrete H3 SAR study starting from compound 51 and investigated the effect of the position of the methyl group on the agonist activity. Analogues 50 and 53, having the methyl group in the aminoethyl side chain

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• derivatization, allowed the obtainment of 18 in high yield under relatively mild conditions, and was extended to the synthesis of 23 analogues, all in high yields (>86%). The catalyst could be recovered from the reaction medium by precipitation and reused up to five times without loss in activity. In 2020, Tyagi

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• Discussion Regarding the synthesis of 5-aryldeazaalloxazines 2 (5-arylpyrimido[4,5-b]quinoline-2,4(1H,3H)-diones), the data in the literature are quite limited, and the known methodology describes the dehydrogenation of initially formed 5,10-dihydro analogues (5-aryl-5,10-dihydropyrimido[4,5-b]quinoline-2,4