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

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• 0.6 mm. 1H NMR spectroscopy Solution-state 1H NMR analyses were performed to quantify the stoichiometric ratios of the CD inclusion complexes, and all of the crystalline samples obtained by co-precipitation were dissolved in deuterated dimethyl sulfoxide (DMSO-d6) at 23 °C. These analyses were

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• that hydrogen bonding is considered as one of the key factors determining the selectivity of catalyst-free sulfoxidations [68]. In such reactions, the selectivity of sulfide oxidation by oxone (sulfoxide/sulfone ratio) was controlled by the solvent nature (deeper oxidation was observed in water than in

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling

• Elenilson F. da Silva,
• Krist Helen Antunes Fernandes,
• Denise Diedrich,
• Jessica Gotardi,
• Marcia Silvana Freire Franco,
• Carlos Henrique Tomich de Paula da Silva,
• Ana Paula Duarte de Souza and
• Simone Cristina Baggio Gnoatto

Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161

• , showing the anti-RSV or protective effect of the compounds. Also, we evaluated the cytotoxic effects of these compounds in VERO, HEP2, A549, and B16F10 cells. Control cells were treated with 1% dimethyl sulfoxide (DMSO), which was used to dilute the test compounds. Our results showed that the introduction

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• . The tuning of the energy order of the CT and LE states is achieved by oxidation of the PTZ unit into the corresponding sulfoxide, whereas conformation restriction is imposed by introducing ortho-methyl substituents on the phenyl linker, so that the coupling magnitude between the CT and the 3LE states

• electron-donating ability of the PTZ unit, and consequently the CT state energy, was achieved by its oxidation to yield the corresponding sulfoxide. The conformation restriction was imposed through introducing ortho-methyl substituents on the phenyl linker. TADF was observed for the dyads and the triad

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• to be dissolved in deuterated dimethyl sulfoxide. Then, the buffer solution was added and mixed in a 1:1 (v/v) ratio just before starting the measurements. The samples were kept at ambient temperature (20–25 °C). All measurements for a given pH value were repeated at least three times with about 10

• of a pH meter. Because of the poor solubility of the pro-fragrance in water, it had to be dissolved in 0.5 mL of deuterated dimethyl sulfoxide. Then, the buffer solutions (0.5 mL) were added and mixed just before starting the measurements. The samples were kept at ambient temperature (20–25 °C

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• reaction mechanism of 10ab synthesis, we continued to investigate four possible reaction pathways (1–4) corresponding to the green, blue, red, and black lines on the PES in different solvents, including ethanol, chloroform and dimethyl sulfoxide (DMSO) at the same level of theory. Especially, ethanol is

• possible pathways of forming 10ab were considered in ethanol, chloroform, and dimethyl sulfoxide (DMSO) solvents, in which ethanol was used in the experimental work, based on the Polarizable Continuum Model (PCM) method [49]. Similar to the calculations in the gas phase, the geometrical structures were

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• a narrower residence time distribution and higher yields (see Table 2). C–O coupling reaction Finally, we evaluated the use of the capillary-based reactor for the related C–O coupling of 4-iodobenzotrifluoride and N-(Boc)-proline with N-tert-butylisopropylamine (BIPA) in dimethyl sulfoxide (DMSO

• sulfoxide. Flow diagram of the experimental setup loaded in an injection loop with the reaction mixture. Flow diagram of the experimental setup adopted and time necessary to obtain steady-state conditions. (a) Reaction profile for a residence time of 3 hours. Stable conditions are obtained after about 12 h

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• shifted by 0.8 ppm and 24.8 ppm in the 1H and 13C NMR spectra, respectively, in comparison with the signals of the methylthio group of compound 3 (see Supporting Information File 1, Figures S1, S2 and S5, S6). Heating compound 5 with primary and secondary amines in dimethyl sulfoxide at 50–70 °C for 0.5 h

• gave the corresponding (2-substituted pyrimidin-4-yloxy)acetates 6–9. In order to replace the 2-methylsulfonyl group with a hydroxy group, we tested several techniques. It was found that heating compound 5 with water in dimethyl sulfoxide at 100 °C or boiling for 1 h in water led to hydrolysis of both

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

• Viktor A. Zapol’skii,
• Isabell Berneburg,
• Ursula Bilitewski,
• Melissa Dillenberger,
• Katja Becker,
• Stefan Jungwirth,
• Aditya Shekhar,
• Bastian Krueger and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

• using triethylamine as base to give the corresponding 3-thiopyrazoles 9a–e in moderate yields (28–69%). By oxidation of sulfane 9d with m-chloroperbenzoic acid in chloroform at room temperature the sulfoxide 10d was obtained in 43% yield (Scheme 7). For comparing the biological activity of the newly

• . Interestingly, the oxidation of the sulfur atom in pyrazole 9d (EC50 = 1.1 ± 0.04 µM) improved the antimalarial activity by a factor of more than three (sulfoxide 10d, EC50 = 0.3 ± 0.01 µM). In our experiments we used the established antimalarial drug amodiaquine as control. As shown in Table 1, the EC50 of

• synthetic building block 2-nitroperchlorobutadiene (1). 3-(Alkyl)(2-hydroxyethyl)aminopyrazoles 7 are accessible from the reaction of oxazolidine derivative 6 with 7-chloro-4-hydrazinylquinoline. Oxidation of sulfane 9d led to the formation of the pharmacologically interesting sulfoxide 10d. The newly

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• [22]. Moreover, the E geometrical isomer in the –CH=N- double bond has a higher percentage when in dimethyl sulfoxide-d6 solution. On the other hand, the Z isomer can be stabilized in less polar solvents by an intramolecular hydrogen bond. In the present study, the spectral data were recorded in CDCl3

• the series of compounds 3aa–fa and 3bb–be was carried out using chloroform (CHCl3), methanol (MeOH) or dimethyl sulfoxide (DMSO) solutions. As comparison, the UV–vis absorption spectra of compounds 3ea and 3be, which contain the nitro group in two different ring positions of the molecules recorded in

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• , failed under similar procedures. Abbreviations TFA, trifluoroacetic acid; DMSO, dimethyl sulfoxide; THF, tetrahydrofuran, TLC, thin-layer chromatography, LC–MS, liquid chromatography/mass spectrometry. Structural differences of several known (2–4) and so far unknown (5 and 6) pyrazolo[3,4-d][1,2,3]-3H

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• nitrate (CAN) [41], 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO)/CuCl [51], K2S2O8 [36], dimethyl sulfoxide (DMSO)/O2 [52], PhI(OAc)2/benzoyl peroxide (BPO) [47], Dess-Martin periodinane, N-bromosuccinimide (NBS), N-hydroxyphthalimide (NHPI)/Co(OAc)2/O2 [53], H2O2/tetrabutylammonium iodide (TBAI) [43], CBr4

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• when the components are light sensitive at short wavelength region and spatial control is required. Experimental Materials Red phosphorus (98.9%), tin (99.5%), and tin(IV) iodide (95%) were purchased from Alfa Aesar. Ethyl alcohol (absolute) was obtained from Sigma-Aldrich. Dimethyl sulfoxide (DMSO

• ) was purchased from Merck. All chemicals and solvents were used as received without further purification for synthesis of black phosphorus. Benzyl bromide (Merck), phenylacetylene (Sigma), propargylamine (Sigma), propargyl alcohol (Sigma), d-dimethyl sulfoxide, (DMSO-d6, Merck), N,N,N’,N’’,N

• ’’-pentamethyldiethylenetriamine (PMDETA, Aldrich), sodium azide (NaN3, Panreac), copper(II) chloride (CuIICl2, Merck), black phosphorus, dimethyl sulfoxide (DMSO) was used as received. Propargyl acrylate (Sigma), styrene (Merck) were purified before by using a basic alumina column to remove the inhibitor and then stored in the

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• , agrochemical, and organic synthetic chemistry. For example, 5-selenyl- and 5-sulfenyl-appended nicotinates 18c and 19c could be oxidized by mCPBA to the corresponding selenoxide, sulfoxide, and sulfone derivatives 22, 24, and 25, respectively. In addition, 5‑selenyl-substituted nicotinate 18c could be

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• al. reported a Hg(II) chloride-mediated cyclization reaction of 2-alkynylphenyl alkyl sulfoxide 179 to synthesize benzothiophene derivatives 180 with good yields [114]. In this case, the reaction was believed to proceed via the initial formation of metal carbenoids followed by a sequential C–H

• . Synthesis of tricyclic heterocyclic scaffolds. HgCl2-mediated cyclization of 2-alkynylphenyl alkyl sulfoxide. a) Hg(OTf)2-catalyzed cyclization of allenes and alkynes. b) Proposed mechanism of cyclization. Stereoselective synthesis of tetrahydropyran derivatives. a) Hg(ClO4)2-catalyzed cyclization of α

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• , Procter used a similar strategy to that reported by Hamashima for the synthesis of similar molecules 125 with good to moderate yields using electron-donating groups at the indole ring. The yields decreased with indoles having electron-withdrawing groups (Scheme 16c) [86]. Here diallyl sulfoxide (123) was

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Regioselective N-alkylation of the 1H-indazole scaffold; ring substituent and N-alkylating reagent effects on regioisomeric distribution

• Ryan M. Alam and
• John J. Keating

Beilstein J. Org. Chem. 2021, 17, 1939–1951, doi:10.3762/bjoc.17.127

• 1H-indazole, employing NaHMDS in tetrahydrofuran (THF) or dimethyl sulfoxide (DMSO), and observed solvent-dependent regioselectivity [24]. Mechanistic hypotheses, based on elegant experimentation, were proposed to underline the roles that tight and solvent-separated ion pairs played in the observed

Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones

• Girish Suresh Yedase,
• Sumit Kumar,
• Jessica Stahl,
• Burkhard König and
• Veera Reddy Yatham

Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121

• Br2, MnO2, hypervalent iodine reagents, chromium-based reagents, activated dimethyl sulfoxide, KMnO4, OsO4, or metal-based catalysts and peroxide were used [7][8][9][10][11][12][13][14][15][16][17]. Most of these protocols produce harmful waste and some of the oxidizing reagents are considered toxic

Total synthesis of ent-pavettamine

• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99

• -pavettamine rather than pavettamine. Chain extension and stereoselective ketone reduction were achieved using the (R)-methyl p-tolyl sulfoxide chiral auxiliary to give the desired 1,3-syn-diol C5 unit. A protecting-group strategy was also developed for the orthogonal protection of the alcohol and amine

• functional groups as they were unveiled. The functionalized C5 fragments were coupled via reductive amination revealing the C10 carbon backbone. Deprotection of the alcohol and amine functional groups successfully provided ent-pavettamine as a TFA salt. Keywords: chiral sulfoxide; ent-pavettamine

• achieve an improved yield of intermediate 4 was met. Subsequent TBS protection of the secondary alcohol 6 gave rise to compound 7 in a moderate yield of 65%. Once the ester precursor 7 had been successfully synthesized, the next step involved conversion of the ester into its β-keto sulfoxide via

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• with CH2Cl2, acetone, and finally with ethyl acetate to give 11 (3.13 g, 92%) as a yellow solid. Synthesis of 2,7,12-tribromo-5,5,10,10,15,15-hexabutyl-10,15-dihydro-5H-diindeno[1,2-a:1',2'-c]fluorene (5): Compound 11 (1.5 g, 2.59 mmol), dimethyl sulfoxide (20 mL), and potassium tert-butoxide (2.61 g

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• treated with organometallic reagents to evaluate which combination of sulfoxides and organometallic reagents yielded alkynes the most efficiently. The use of 1-chlorovinyl p-tolyl sulfoxide and isopropylmagnesium chloride was optimal for this purpose. A variety of 1-chlorovinyl p-tolyl sulfoxides were

• prepared from carbonyl compounds and chloromethyl p-tolyl sulfoxide and were converted into alkynes via the sulfoxide/magnesium exchange reaction and subsequent Fritsch–Buttenberg–Wiechell (FBW) rearrangement of the resulting magnesium alkylidene carbenoids. The mechanism of the FBW rearrangement of

• magnesium alkylidene carbenoids was studied by using 13C-labeled sulfoxides and by using DFT calculations. Keywords: alkyne; 1-chlorovinyl p-tolyl sulfoxide; DFT calculation; Fritsch–Buttenberg–Wiechell rearrangement; magnesium alkylidene carbenoid; Introduction Alkynes are important compounds in organic

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90