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

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• azides substituted with heteroaryls such as thiophene (4i) or a bromofuran (4j) were obtained in 62% and 54% yield, respectively. When the azido-alkynylation was carried out on 1,2-dihydronaphthalene, 4k could be obtained in 71% yield and 3.8:1 dr. As expected, the configuration of the major

• worked well in the transformation, affording homopropargylic azides 4n–q in 60–77% yield. The reaction appears to be sensitive to the steric hindrance of the nucleophile: addition of a mesitylalkyne only formed 33% of 4r. Pleasingly, heteroaryl substituents were tolerated, 4s bearing a thiophene was

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• ligand IIIa possesses lower catalytic activity than the pyridine derivative (for TON and TOF parameters see Supporting Information File 1, part S5). The conversions were poor in the case of less reactive aldehydes, e.g., thiophene-2-carbaldehyde, and 3-phenylpropionaldehyde. To achieve satisfactory

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• Physical and Organic Chemistry, Southern Federal University, Rostov-on-Don 344090, Russian Federation North Caucasus Federal University, Stavropol 355009, Russian Federation 10.3762/bjoc.20.47 Abstract A series of novel photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with

• sequential addition of Fe2+ and AcO−, we synthesized N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline substituent and studied the spectral-luminescent, photochromic and ionochromic properties. The phenanthroline moiety was incorporated into the molecule due to the

• ]thiophene-3(2Н)-ones 2a–c with a terminal phenanthroline substituent was (E)-2-(((1,10-phenanthrolin-5-yl)amino)methylene)benzo[b]thiophen-3(2H)-one (1), obtained by condensation of 3-hydroxybenzo[b]thiophene-2-carbaldehyde with 5-aminophenanthroline in acetonitrile (Scheme 1). (Z)-N-((3-Oxobenzo[b]thiophen

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• substituted at positions 2 and 5 with 1,8-dibromonaphthalene using 5 mol % PdCl(C3H5)(dppb) catalyst with KOPiv as the base in DMA (Scheme 3). From 2,5-dimethylthiophene or 1,2,5-trimethylpyrrole, the desired acenaphtho[1,2-c]thiophene 16 and acenaphtho[1,2-c]pyrrole and 17 were obtained in 60% and 56% yield

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• dithienonaphthalene products (e.g., 16) exhibit very different fluorescence properties, S-extrusion from thiophene-annelated thiepines was consequently exploited for peroxide sensing. Very recently, Zhou et al. reported the synthesis of S-doped phenanthrene and triphenylene derivatives via the thermally-induced ring

• contraction of thiepine scaffolds, fused with two or three thiophene, thiopyran or polycyclic hydrocarbon moieties [64]. Indeed, a series of polyannelated thiepine derivatives were prepared according to an original approach, consisting in the introduction of the bridging sulfur atom from the outset of the

• naphthyl substituents carrying each an alkyne moiety on the ortho position. Ring expansion of both thiophene units in 19 was then triggered by platinum catalysis to generate the corresponding thiopyrans, and finally the bromine atoms located on the latter rings were exploited for the ring closure of the

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• reaction system, yielding product 3ak in good yield. Furthermore, heteroaromatic rings, such as pyridine (2l), thiophene (2m), benzoxazole (2n), and benzimidazole (2o) all afforded the desired products (3al–ao) in satisfactory yields. Subsequently, we investigated the substrate scope of amines, which is

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

• trimethylgallic acid bearing multiple methoxy groups afforded the desired product 3ma in excellent yield (99%). Noteworthy to mention, substrates containing naphthalene, furan, and thiophene rings also efficiently underwent reaction leading to the quinoline C5-brominated products in excellent yields (3na–pa). In

• contrast, side products, substituted on the naphthalene, furan, or thiophene ring were not detected. This protocol was also compatible with linear, branched, and cyclic aliphatic acid-derived substrates (3qa–va). Surprisingly, small ring-containing substrates displaying significant ring strain were stable

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

• layers are composed of various aromatic π-conjugated small molecules/polymers including thiophene, anthracene, carbazole, and triphenylamine [9][10][11][12][13]. Thienothiophenes are two annulated thiophene rings having four isomers, among which the most widely used isomer is thieno[3,2-b]thiophene (TT

• ]thiophene (TT) core. The optical band gap (Eoptic) of DMB-TT-TPA (8) was calculated to be 2.52 eV from the onset wavelength of the absorption spectrum at 491 nm. The compound demonstrates high quantum efficiencies in the solid-state and in solution (THF) of 41 and 86%, respectively. The considerable quantum

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• , heteroaryl-bearing tosylimines were also tested. The thiophene-substituted tosylimine 2j gave hexaphyrin 4j in 17% yield and porphyrin 3j in 10% yield, whereas the indole-bearing tosylimine gave only A3B-porphyrins but no A4B2-hexaphyrin (Table 1, entries 10 and 11). Signals of trace amounts of A2B2-type

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

• based on Qxs is of significant interest in the field of organic electronics. A compelling indication of this potential is the remarkable achievements made by a relatively simple polymer, poly[(thiophene)-alt-(6,7-difluoro-2-(2-hexyldecyloxy)quinoxaline)] (PTQ10). PTQ10 has demonstrated impressive power

• ]thiophene in different ratios to produce three copolymers, Qx1a, Qx1b and Qx1c (Figure 2). This strategy reduced aggregation and improved the performance and stability of copolymers, with Qx1c achieving a PCE of 4.81% with PTB7-Th donor in an all-PSC device. Moreover, the broadened absorption band indicated

• to the Qx moiety of Qx29, producing a new NFA, Qx31, as well as the thiophene side chains of the p-type polymer PE61 to fine-tune the optoelectronic properties. The PCE of PE62:Qx31-based solar cells improved from 4.19 to 9.78% with a relatively high Voc of 1.09 V, and the PE61:Qx31-based devices

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• behavior, suggesting that the steric configuration of the sulfoxide group and the structure of the sugar chain may not influence the anti-inflammatory effect. In contrast, compound 3 did not show anti-inflammatory activity, suggesting that a thiophene ring or a sulfoxide group in breynins is involved in

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• catalyst to produce radicals at the 2- and 5-positions of thiophene and synthesized four types of poly(3-alkylthiophene)s (PATs) with different linking ways (Scheme 10). 2.2 Polymerization by thiol–ene chemistry The thiol–ene reaction (also called alkene hydrothiolation) is the anti-Markovnikov addition of

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• carboxylic acid and pivalic anhydride than aryl bromide. The halides provided versatile synthetic handles for further transformations. Substrates bearing thiophene (3k) furan (3j) and other heterocycle (3l,m) moieties were also applicable to this reaction. This protocol allowed for the coupling of not only

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• photoreaction can be carried out for starting compounds with both donor and acceptor substituents in the aryl fragment. However, it is interesting to note that the UV irradiation of thiophene containing pyrimidines 9g and 10g leads to a complicated mixture of unidentified products. Probably, this is due to

• photochemical side processes involving the thiophene ring. Conclusion In summary we have developed an approach for the preparation of pyrimidines with an allomaltol fragment. The suggested method started with the synthesis of pyrimidines from the reaction of 2-(1-(dimethylamino)-3-oxo-3-arylprop-1-en-2-yl)-3

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

• derivatives were synthesized. Benzyl ((4-chloro-6-(4-methylphenyl)thieno[2,3-d]pyrimidin-5-yl)methyl) allylphosphonate (44) was prepared in 87% yield from 4-chloro-3-(chloromethyl)-2-(4-methylphenyl)benzo[b]thiophene (42) and benzyl hydrogen allylphosphonate (43) via alkylation in the presence of Cs2CO3 in

• from 3-bromobut-3-en-1-yl ethenyl(phenyl)phosphinate and 2-bromophenylmethyl alk-1-enylphosphinates. Synthesis of thieno[2,3-d]pyrimidine-fused 2-hydroxy-1,2-oxaphosphonane 2-oxide from benzyl hydrogen allylphosphonate and 4-chloro-3-(chloromethyl)-2-(4-methylphenyl)benzo[b]thiophene. Synthesis of 3

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• C–H activation as well as its involvement in the dehydration process. This reaction proceeded smoothly with a variety of both EWGs and EDGs on the 2-phenylpyridine. Interestingly, when swapping the pyridine directing group for thiophene or furan, yields were improved although quinolinyl and

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• aryl residue allowed the monofunctionalization to occur selectively. Also, amide 1g bearing a disubstituted arene was successfully functionalized in 59% yield. Finally, the difunctionalized thiophene derivative 2h was obtained in 56% yield. In 2016, Wang's group developed another methodology for the

• broad range of functional groups such as halogens, ester, aldehyde, cyano, and nitro (36c–g, 36–74% yield). It is noteworthy that a disubstituted compound 35j and a thiophene derivative 35k were also efficiently difluoromethylthiolated (36j and 36k, 72% and 65%, respectively). α-Substituted