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

• performed on a Bruker Apex Kappa-II CCD diffractometer. The solvents used, dimethyl sulfoxide and 1,4-dioxane, were purchased as dry solvents and applied without further purification. Other reagents, catalysts, ligands, acids, and bases were used as purchased from commercial suppliers. Column chromatography

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• solvents including dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), toluene, acetic acid (AcOH) and water (Table 1, entries 9–13) were carried out. However, polar solvents such as AcOH and H2O were proved to be unsuitable for this reaction. For catalysts, we found that Cu(OAc)2 gave the best results

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• % purity) [26] provided a more selective reaction, no water-based work-up was needed and the pure product was obtained by simple recrystallization from ethanol in yields up to 88%. The oxidation step thiol → sulfoxide was fast and full conversion to the intermediate was achieved in one hour for most

• substrates, but the step sulfoxide → sulfone was entirely slower and required stirring overnight (except for 8d (R = iC3H7)). With 2-chloro-6,7-dimethoxy-4-sulfonylquinazolines 8 in hand, we started to explore the reactivity in SNAr reactions (Scheme 5). Sulfonyl group dance reactions did not work in

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

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

• Alexander S. Hampton,
• David R. W. Hodgson,
• Graham McDougald,
• Linhua Wang and
• Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

• difluoromethylphenyl sulfoxide offer the possibility of transferring difluoromethylene groups directly into organic systems [19][20][21][22][23][24][25] and there is now a very extensive literature on carbon–carbon bond-forming reactions using these and other difluoromethylated building blocks [3][26][27][28][29][30

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

• and the related sulfoxide 4, it was first demonstrated that electron injection is able to trigger S- (or SO-) extrusion, electrochemically but also chemically, employing decamethylcobaltocene CoCp*2 as a reducing agent (Scheme 4, top). Under the latter conditions, the target PBI compound 6a was

• obtained in 89% yield on a ≈10 mg scale from its sulfoxide precursor 4a. In anticipation of device fabrication, activation methods which do not require the addition of chemical reagents were next tested. Thermally-induced S-extrusion was first investigated by means of thermogravimetric analysis: the

• thiepine precursor 3a exhibited a mass decrease at 300 °C in agreement with the expected elimination of sulfur to yield almost quantitatively the corresponding PBI 6a. Its sulfoxide analogue 4a exhibited higher thermal reactivity, with the loss of SO identified at lower temperature (225 °C). As a proof of

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

• introduced a pioneering method for synthesizing air- and moisture-stable arylthianthrenium salts [11]. This novel approach involves the utilization of tetra-fluorothianthrene sulfoxide (TFT=O) or thianthrene sulfoxide (TT=O), which react with arenes under mild conditions, exhibiting exclusive

• -metal-catalyzed cross-coupling [32][33] and aminofunctionalization [34] of alkenes were achieved, benefiting from the unique reactivity of organothianthrenium species that are generated through the reaction of alkenes and thianthrene sulfoxide (TT=O) or thianthrene (TT) (Scheme 1b). Alcohols are widely

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

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

• chain in dimethyl sulfoxide. Furthermore, the solvent-driven shuttling motion of the macrocycle was observed to exert a discernible effect on the aggregation of the amphiphilic molecular system. In particular, changing the solvent led to the generation of interlaced nanofibers, perforated capsules, and

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• monomer 22 much less significantly. With less electron-deficient NDIs carrying two sulfide donors in the core, the catalytic activity of 45 dropped below that of fullerene monomer 22. Oxidation of the sulfide donors into sulfoxide acceptors increased the catalytic activity much less than expected, resting

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

• to a dimer 37 was achieved using N,N-dimethylformamide, dimethyl sulfoxide, or acetonitrile. Interestingly, the dissolution of compound 37 in CHCl3, MeOH, or EtOH resulted in the interconversion to 36 within 1–2 days, as evidenced by 1H NMR spectroscopy. The Ravikanth group has developed an

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

• ], these differences indicate that the sulfoxide moieties in the aglycone of 1 and 2 are isomers. The remaining NMR resonances (Table 2) and 2D NMR spectroscopic data (Figure 2) showed that the glycosyl group of 2 was the same as that of 1. This assignment was further supported by HPLC-based monosaccharide

• 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

• resulting dark blue crystals were dissolved in dimethyl sulfoxide, and the absorbance of the obtained solution was measured at 492 nm. ELISA The concentrations of IL-1β and IL-6 in the culture medium after 12 h of LPS treatment were measured using Quantikine ELISA kits for mouse IL-1β and IL-6 (R&D Systems

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• , peptides, drugs and saccharides reacted smoothly with N-alkynylthiophthalimides in the presence of TFA as a catalyst. Also, aliphatic and aromatic thiols reacted with N-alkynylthiophthalimide and sulfoxide 149 to obtain acyl disulfides 151 through alkynylthiolation and hydrative oxyarylation in the

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• deprotonation the latter with sodium hydride base. The compound shows poor solubility in most common organic solvents with moderate solubility in dichloromethane, 1,2-dichlorobenzene and dimethyl sulfoxide (DMSO). Compound 4BGIPN was characterized by high-resolution mass spectrometry (HRMS), elemental analysis

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• , version 4.4 SR1). The NMR spectra were recorded on an Avance III 700 (Bruker Biopsin, 1H: 700 MHz, 13C: 176 MHz) and/or an Avance III 500 (Bruker Biospin, Ettlingen, Germany, 1H: 500 MHz, 13C: 125 MHz) instruments. Deuterated methanol and dimethyl sulfoxide were used in the measurements. Coupling

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• phosphine oxide, and selenides to selenoxides. Sulfoxide, phosphine oxide, and selenoxide-containing molecules have diverse applications in the pharmaceutical industry [10], as chiral auxiliaries or as ligands for asymmetric metal catalysis [11], and in materials such as polymers [12][13] and flame

• positive impact on the reaction outcome. By running the reaction in the presence of oxygen and in the absence of a photocatalyst, a quantitative conversion into the sulfoxide was obtained within 60 minutes in batch (Table 1, entry 1). To shed more light on what could be the absorbing species within the

• option to use an additive (vide supra) to accelerate the reaction. For products 2f, 2h, and 2l the reaction could be stopped to selectively obtain the sulfoxide, but over prolonged reaction times some side products were observed. As expected, the protocol was not applicable to substrates containing

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• the energy ordering of the transient species involved in the TADF photophysical process, the electron-donating strength of the PTZ moiety is lowered by oxidation of the sulfur atom to the corresponding sulfoxide. Conversely, the electron-accepting capability of the NI unit is varied by introducing

• substituents on the NI unit (NI-PTZ-F, NI-PTZ-Ph, NI-PTZ-CH3, NI-PTZ-OCH3), and the electron-donating ability of the PTZ unit was modified by oxidation of the sulfur atom to the sulfoxide (NI-PTZ-F-O, NI-PTZ-Ph-O, NI-PTZ-C5-O). The advantage of the oxidation approach is that almost only the energy of the 1CS

• dimension to tune the photophysical properties, i.e., the phenothiazine unit can be oxidized to the sulfoxide, thus tuning the energy states ordering between the 1CS, 3CS, and 3LE states. Moreover, the advantage of this molecular structure design is the ability to change only one factor (such as the CS

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• (phosphite/phosphine-pyridine amide, phosphine-sulfoxide, phosphoramidite, MINBOL, see Figure 1) and they usually showed excellent diastereoselectivity (dr >20:1). The catalytic systems even with low catalyst loadings tolerated both electron-donating and withdrawing groups on the aromatic substituents

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

• corresponding sulfoxide and the sulfone was possible and the corresponding products were obtained in 98% and 95% yields, respectively. This reaction was successfully expanded to the trifluoromethylthiolation of derivatives bearing various directing groups such as substituted pyridines (4 examples, up to 84

• approach. Of high interest, the modularity of the SCF2CO2Et was highlighted by its conversion into various other fluorinated residues (amide, carboxylic acid) and its selective oxidation into the corresponding sulfoxide and sulfone. I.5) Trifluoromethylselenolation of aromatic and vinylic C(sp2)–H bonds by

• allowing the formation of a C(sp2)–ORF bond through palladium-catalyzed C–H bond activation [169]. Using Pd(OPiv)2 as the catalyst in the presence of PhI(OAc)2 (PIDA), the naphthalene sulfoxide 43a was 2,2,2-trifluoroethoxylated in 82% yield (Scheme 21). The substituent of the sulfoxide part does not

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• ions. Further demethylation [40] and oxidation of the thioether followed by thermal elimination of the intermediate sulfoxide gave 2 in 98% yield after two steps (Scheme 7). The authors also achieved the synthesis of (±)-1 from combretastatin D-2 (2). Protection of the hydroxy group in compound 2 using

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• - [16], hydroxylamino- [17], or alkylamino-CDs [18], monosubstituted at position C-6. In addition, the tosyl functional group can be oxidized to an aldehyde using a non-nucleophilic base in dimethyl sulfoxide (DMSO) [19]. The monoaldehyde CDs can be further oxidized selectively to afford the

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• reasons [1]. Halogenated solvents such as chlorobenzene or dichloromethane are widely used in polymer production, but their toxicity and high energy consumption for synthesis make them unwanted for widespread commercial use. Many other dipolar solvents such as dimethyl sulfoxide (DMSO), N,N

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• reaction of 1 with bis(benzonitrile) palladium chloride generates the palladium chloride complex of 5 from which 5 can be liberated by treatment with dimethyl sulfoxide [43]. Compound 5, with tentatively assigned structure, was first obtained as a pyrolysis product of elemol phenylurethane (6) [44]. Its

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• excess of a perbenzoic acid, as shown for the oxidation of 6 to 7 [33][34]. Partial oxidations are also possible, but lead to mixtures of sulfoxides, including cis- and trans-sulfoxide stereoisomers (see also chapter 6). For a more detailed and extensive discussion of the synthesis of 1,4-dithiin

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• (Table 1, entry 11). These results indicate that the accessibility of the phosphorus center is important. Next, the solvent was investigated. Replacing acetonitrile with dimethyl sulfoxide (DMSO), or dimethylacetamide (DMA), or acetone, or ethyl acetate (EA), resulted in inferior yields (Table 1, entries