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

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

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

• observed. The synthesis of N-acetyl diazocines connected to heteroaromatic aromatic systems 14–16 was less successful. The pyridine-substituted N-acetyl diazocine 14 was formed in yields of 7% or 19% while furan- 15 and thiophene-substituted N-acetyl diazocine 16 could not be obtained. The reaction with

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• -thieno[2,3-f]isoindoles in excellent yield (Scheme 4). The H-shift does not take place at the last stage, which correlates with the results obtained earlier. This shows the possibility of replacing the furan ring with a thiophene one, which significantly expands the possibilities of this approach for

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• catalysis for carbene transfer reactions and radical-based functionalizations [41]. In another study by Derksen et al., thiaporphyrins were introduced as highly effective catalysts for red-light-mediated photoreductive dehalogenation [42]. These thiophene-modified porphyrins exhibit excellent absorption

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• ) was dissolved in anhydrous THF (30 mL) under argon atmosphere. A 1.6 M n-BuLi hexane solution (2.3 mL, 3.6 mmol) was slowly added dropwise to the solution at −78 °C, and the mixture was refluxed for 1 h. 3-Methyl-2-(perfluorocyclopent-1-en-1-yl)benzo[b]thiophene [69] (1.1 g, 3.6 mmol) dissolved in THF

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

• Marios Zingiridis,
• Danae Papachristodoulou,
• Despoina Menegaki,
• Konstantinos G. Froudas and
• Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

• obtained 15 diversely substituted heteroannulated pyrimidones, employing privileged thiophene, quinoline and indole scaffolds in a rapid fashion, without the need of column chromatography, in a parallel setup. Heteroannulated pyrimidones in drug discovery: blockbuster drugs that are based on the privileged

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• slightly diminished reactivity (23c and 23d). In addition, poor reactivity was observed with dioxazolones bearing thiophene, implying that the undesired coordination of sulfur to copper reduces the reactivity (23e). Despite the reduced reactivity, excellent enantioselectivity was still maintained. Moreover

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

• , Ankara 06800, Türkiye 10.3762/bjoc.20.273 Abstract Acenaphthylene-fused heteroarenes with a variety of five- and six-membered heterocycles such as thiophene, furan, benzofuran, pyrazole, pyridine and pyrimidine were synthesized via an efficient Pd-catalyzed reaction cascade in good to high yields (45–90

• from certain plant species (Figure 1) [12]. The acenaphthylene-fused thiophene-based heteroarene 3 is another heterocyclic fluoranthene analogue, which was used as an organic semiconductor in transistors [13]. The synthesis and coordination complexes of the acenaphthylene-fused N-heterocyclic (NHC

• -catalyzed annulation reaction between bromo-chloronaphthalene dicarboximides 6 and heteroarylboronic esters that enabled the syntheses of acenaphthylene-fused thiophene and indole derivatives 7 having donor-acceptor units (Scheme 1a) [40]. In 2021, Jin and co-workers developed an elegant Pd-catalyzed

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

• . Access to the dianion of BFC presages an interesting diradical and this was achieved by inclusion of mesityl protecting groups [27]. Extension of the BFC model with thiophene provides further interesting materials [28]. A reasonable corollary to this behavior would assert that derivatives of TBF and

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

• by sunlight [99]. This marked the first application of these corroles as photoredox catalysts. They synthesized three free base corroles 98–100 featuring electron-withdrawing substituents at the meso-positions and tested them for the arylation of furan (75), thiophene (102), and N-Boc-pyrrole (103

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

• with thiophene favored the formation of phenylated products as the major outcome. Additionally, mercaptoazoles were found to be compatible with this protocol, expanding its applicability to include these compounds. The functionalization of peptides and proteins plays a vital role in the development of

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

• . Thioisoindigo-N-glycosides The condensation of isatin-N-rhamnoside β-16a with 2,3-dihydrobenzo[b]thiophen-2-one (73), available in two steps from benzo[b]thiophene [61], afforded thioisoindigo-N-rhamnoside β-74a in 45% yield (Scheme 41) [60]. Like in the case of β-64a, deprotection proved to be unsuccessful

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

• (Table 3, entries 7 and 8). The same success could not be replicated for OET-o-BrPPs with no reactivity being observed by TLC or by mass spectrometry. Likewise, a microwave-assisted coupling [48], resulted in no product formation (Table 3, entry 9). Thiophene-3-ylboronic acid (21) was also chosen for

• illustrates that coupling phenyl, thiophene or other aryl moieties at this position would be extremely difficult. Furthermore, the distance between the o-bromine atoms and the nearest carbon neighbor of the β-ethyl groups is 3.7 Å, further complicates the success of coupling at this position. As discussed

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• that the dinuclear copper complex is the precursor of the active monocopper species which is involved in the turnover-limiting step (Scheme 27). Subsequently, Zhu and Xu et al. [73] also achieved the distal enantioselective heteroarylation of yne-thiophene carbonates by applying a simpler p-OMe

• substituted pybox ligand (Scheme 28, 26a–m). The thiophene unit of the carbonate could also be replaced by benzothiophene (Scheme 28, 26h) or furan (Scheme 28, 26m), and pyrrole (Scheme 28, 26j), phenol (Scheme 28, 26k); coumarin derivative (Scheme 28, 26n), and dibenzylamine (Scheme 28, 24a) could also

• substitutions of 5-ethynylthiophene esters. A series of C-, N-, O-, and S-nucleophiles could react smoothly to obtain various thiophene derivatives with different functional groups (Scheme 29, 28a–t). Control experiments showed that terminal alkyne and copper catalysts are crucial for the smooth progress of the

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• cyclopropylboronic acid (4n) achieved to give 2n in a 71% yield (Table 3, entry 13). When thiopheneboronic acid 4o was used as a coupling partner, the thiophene ring could be installed on 1a in a comparatively low yield of 31% (Table 3, entry 14). In addition, we investigated the substrate scope of 1 in the Suzuki

• 5l) could be introduced into 1a in 76% or 52% yields, respectively (Table 4, entries 10 and 11). Reactions using acetylenes possessing a hydroxy group, amino group and thiophene proceeded well (3m–o) (Table 4, entries 12–14). Hexa-1-yne 5p and cyclopropylacetylene (5q) afforded 3p and 3q

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• heteroaryls other than thiophene under standard conditions. Schreiner et al. established a further protocol for the one-pot synthesis of pyrazoles, where the alkynoyl moiety is generated by copper-catalyzed carboxylation of terminal alkynes followed by alkylation with methyl iodide, forming propiolic acid

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

• hydration reaction of carbon dioxide to bicarbonate, cyanates to carbamic acids, aldehydes to gem-diols, etc., and represent a potential therapeutic target for diseases like osteoporosis, edema, obesity or cancer [29]. Alım et al. [30] evaluated a series of thiophene sulfonamides based on the high stability

• 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

• capacity to antagonize human nAChRs (nicotinic acetylcholine receptor) as these are of clinical importance in developing tobacco-derived diseases. From the range of propiophenone derivatives elaborated tackling dopaminergic activities, thiophene 31 showed weak inhibitory activity towards α3β4 and α4β2

Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

• Sabyasachi Chakraborty,
• Eduardo Mayo Yanes and
• Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

• in size, composition, and aromatic character: benzene, pyridine, pyrazine, borinine, 1,4-diborinine, 1,4-dihydro-1,4-diborinine, borole, pyrrole, furan, thiophene, and cyclobutadiene (Figure 1A). These building blocks encompass 6-, 5-, and 4-membered rings with aromatic and antiaromatic character

• of the property space covered differs noticeably. Furan, thiophene, and cyclobutadiene all cover a similar region of the property space as the baseline PBHs, which is a relatively small swath that shows a linear relationship – meaning, molecules with higher HOMOs have lower LUMOs and vice versa. In

• values than either furan or thiophene, and that 1,4-diborinine has the strongest LUMO-lowering effect of all building blocks in our library. In addition, these plots can provide further insight into the three building blocks that showed similar coverage as the cc-PBHs, namely, furan, thiophene, and

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• group which might be explained by the electron-rich nature of the thiophene and, thus, a reduced electrophilicity of the neighboring carbonyl group. Likewise, a poor yield (23%) was observed for a 2-fluorophenyl group, presumably due to steric hindrance because of the ortho-substituent. Excellent yields

Synthesis and optical properties of bis- and tris-alkynyl-2-trifluoromethylquinolines

• Stefan Jopp,
• Franziska Spruner von Mertz,
• Peter Ehlers,
• Alexander Villinger and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1246–1255, doi:10.3762/bjoc.20.107

• the 6-position in comparison to the 8-position. The structure of product 9f was confirmed by X-ray crystallography (Figure 3). The thiophene ring in 4-position is in plane with the quinoline core, while the other ring is twisted in an angle of approximately 85°. This might be explained by an

• electronic push–pull interaction of the thiophene and the quinoline moieties via the alkyne. Finally, we focussed on the synthesis of tris-alkynylated quinolines starting from 3,4,8-tribromo-2-(trifluoromethyl)quinoline (11). Starting material 11 was synthesized in very good yield from quinolone 3 by

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• desired products were obtained in good to excellent yields and E-selectivities (Figure 2) [71][72][73][74]. Various substrates (9aa–gc), containing electron-donating, electron-withdrawing, electroneutral groups, and heteroaryl units (2-thiophene and 3-benzothiophene) were obtained in good to excellent

• cyclization of 3-substituted thiophene derivatives. When carrying out the reactions at 60 °C for 24 h, the formation of a 9:1 mixture of the products 13 and 14 in 61% combined yield was observed (Scheme 1) [75]. Under more vigorous conditions (100 °C for 5 h), there was a slight increase in the yield of

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• studies showed that the hemilability and bifunctionality of the thiophene arm attached to the metal play an important role in this transformation for the dehydrogenation and hydrogenation steps. Later, the same complex was successfully used for the α-alkylation of ketones with secondary alcohols to

Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics

• Luca Julianna Tóth,
• Kateřina Krejčová,
• Milan Dejmek,
• Eva Žilecká,
• Blanka Klepetářová,
• Lenka Poštová Slavětínská,
• Evžen Bouřa and
• Radim Nencka

Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91

• compensate this difference. The pyridone derivatives 3a–c exerted an activity resulting in IC50 values of 128.7 μM, 203.8 μM and 88.1 μM, respectively, highlighting that even significantly truncated molecules are capable of RdRp inhibition. A thiophene substituent in position 5 (i.e., 3c) proved to be the

A Diels–Alder probe for discovery of natural products containing furan moieties

• Alyssa S. Eggly,
• Namuunzul Otgontseren,
• Carson B. Roberts,
• Amir Y. Alwali,
• Haylie E. Hennigan and
• Elizabeth I. Parkinson

Beilstein J. Org. Chem. 2024, 20, 1001–1010, doi:10.3762/bjoc.20.88

• described [24]. Thiophene (22) also did not produce any product, which may be due to the differences in the electronics of the sulfur or the lack of electron-withdrawing groups on the molecule. The phenyl-substituted compound 17 was tested but ultimately showed no conversion as well. Although it does have

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• ring instead of a benzene moiety. This was demonstrated by the introduction of thiophene (5r) and furan (5t) to the uracil structure. The molecules 5n and 5o could not be obtained, due to decomposition during the reaction. The structure of 5a was confirmed by X-ray crystallographic analysis. Crystals

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• functional tolerance of this methodology is striking. Especially examples with sensitive aldehyde (175), nitrile (176), N-Boc (177), furan (178), thiophene (179), and even tertiary alcohols (180 and 181) are impressive. The primary drawback of this methodology lies in the synthesis of the ligand L3