Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• synthesized compound 1 agreed with those of natural 1. At this stage the confirmation of the identity of natural and synthesized compounds by structural determination using NMR spectroscopy is often difficult because the NMR spectra of peptidic products vary depending on the conditions in the NMR tube [25][26

Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol

• Emine Salamci and
• Ayse Kilic Lafzi

Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163

• in 90% yield. Thus, the dimesylate 8, which is one of the most relevant precursors for the synthesis of aminocyclitols, was synthesized from the diol 7. The structure of compound 8 was assigned on the basis of NMR spectroscopy. In the 1H NMR spectrum, we observed that methyl signals of the mesylate

• the diazide 9 (Scheme 2). However, the product was determined to be the azidomesylate 10 instead of the expected diazide 9 based on NMR spectroscopy. The position of the azide functionality in 10 was determined from its COSY spectrum. The diagonal peak at 3.97 ppm has cross peaks with the protons

• a positive NOE clearly indicates that the protons H-2/H-7 should have a cis configuration relative to the protons H-1/H-8. Finally, benzyl deprotection with BCl3 of 14 afforded the product 16 in 84% yield. The structure of 16 was assigned on the basis of NMR spectroscopy. Conclusion In summary, we

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• by 1H NMR spectroscopy, phenylbenzimidoyl chloride (17) was observed to be generated (Scheme 3a) (see Supporting Information File 1 for details). When o-aminophenol (1a) was reacted with 17 [41] in a 1:2 ratio, product 8a and diphenylbenzamidine (18) were obtained in 81% and 86% yields, respectively

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• (d2) opens possibilities to quantitative measurements of ApppI in biological samples by mass spectrometry. The synthesized target compound ApppI(d2) was purified by high-performance counter current chromatography and characterized by 1H, 13C, and 31P NMR spectroscopy as well as high-resolution mass

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• basis of 1D and 2D NMR spectroscopy as well as high-resolution mass spectrometry. The absolute configuration of 1 was established by ECD calculation. Compounds 2 and 3 represent rare examples of naturally occurring 9,9'-bisnorlignans. All the isolated compounds were assayed for their inhibitory effects

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

• – cinnamaldehyde, cyclamen aldehyde, lilial, benzaldehyde, anisaldehyde, vanillin, hexanal, heptanal, citral, and 5-methylfurfural. Subsequently, the rate of release of the volatile compound from selected pro-fragrances, as a function of the environment (solvent, pH), was studied by 1H NMR spectroscopy (for

• stability towards hydrolysis. Kinetic studies of the imine hydrolysis by NMR For the kinetic studies of the hydrolysis of imino-CDs, we selected the pro-fragrance 3d made from the most common aldehyde – benzaldehyde. The release of the benzaldehyde (2d) was studied by 1H NMR spectroscopy. Aqueous 0.1 M

• phosphate buffer solutions of pH 1.08, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 10.00 11.00, 12.00, and 12.80 were prepared (see Experimental section) using deuterium oxide instead of water to facilitate NMR spectroscopy experiments. Because of the low solubility of the pro-fragrance in water, it had

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• bromides from one starting aryl aldehyde. Diethyl phosphite was allowed to react with appropriately substituted benzaldehydes in THF for 48 hours at 25 °C to afford diethyl (hydroxy(aryl)methyl)phosphonates 1, which were detected by 31P NMR spectroscopy in THF (21.4 ppm for 1a, 21.0 ppm for 1b, and 21.5

• confirmed by 31P, 1H, and 13C NMR spectroscopy. The 31P{1H} NMR spectra of phosphonium bromides 6 showed a singlet at about 40 ppm, which is typical for phosphonium salts. The 13C{1H} NMR spectra consisted of a doublet at about 20 ppm, corresponding to the carbon atom C1, which is characteristic for the sp3

• (Scheme 3). The structure of 3,4,5-triaryl-1,2-diphosphaferrocene 8b was confirmed by 31P, 1H, and 13C NMR spectroscopy. The 31P{1H} NMR spectrum of 8b showed a singlet at about −10 ppm, shifted upfield by about 210 ppm in comparison to the starting 1,2-diphospholide anion 7b. In the 1H NMR spectra

B–N/B–H Transborylation: borane-catalysed nitrile hydroboration

• Filip Meger,
• Alexander C. W. Kwok,
• Franziska Gilch,
• Dominic R. Willcox,
• Alex J. Hendy,
• Kieran Nicholson,
• Andrew D. Bage,
• Thomas Langer,
• Thomas A. Hunt and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2022, 18, 1332–1337, doi:10.3762/bjoc.18.138

• mol %), Ar atm., 60 °C, 18 h, unless otherwise noted. Isolated yields are reported. a1.0 mmol scale. bHBpin (5.5 equiv). c80 °C. d40 °C. a) Proposed mechanism; b) H-B-9-BBN-catalysed heptanenitrile hydroboration (yield determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as an internal

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• synthetic strategy, which itself was synthesized from Br-DiKTa [28] following a Buchwald–Hartwig coupling. Details of the synthesis are found in Supporting Information File 1. The identity and purity of the molecules were verified using a combination of 1H and 13C NMR spectroscopy, high resolution mass

Ferrocenoyl-adenines: substituent effects on regioselective acylation

• Mateja Toma,
• Gabrijel Zubčić,
• Jasmina Lapić,
• Senka Djaković,
• Davor Šakić and
• Valerije Vrček

Beilstein J. Org. Chem. 2022, 18, 1270–1277, doi:10.3762/bjoc.18.133

• nitrogen intermediate, see Scheme S1 in Supporting Information File 1). In any case, the N7-ferrocenoylation of adenine anion 3 is a viable process, as demonstrated by the 1H NMR spectroscopy evidence (see above), and by the isolation of the N7-ferrocenoylated product. We have continued our study with an

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• Supporting Information File 1. Both compounds were further purified by temperature-gradient vacuum sublimation and characterized by 1H and 13C NMR spectroscopy (Figures S9–S12, Supporting Information File 1) as well as high-resolution mass spectrometry. Photophysical studies and DFT calculations The UV–vis

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

• Yara Cristina Marchioro Barbosa,
• Guilherme Caneppele Paveglio,
• Claudio Martin Pereira de Pereira,
• Sidnei Moura,
• Cristiane Storck Schwalm,
• Gleison Antonio Casagrande and
• Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

• . All products were fully characterized by HRMS as well as 1H and 13C NMR spectroscopy. Thus, this approach is valuable for promoting the synthesis of N-phenyl-1H-indazoles in a higher yield than that reported in the literature using copper catalysis and the same substrates. This study also prompted the

• of CuI, only the product 2i’ or 4i’, respectively, was detected by 1H NMR spectroscopy in the crude reaction mixture (Figures S7–S10 and Figures S11–S14, respectively, Supporting Information File 1). This result shows that o-fluorinated arylhydrazones may be suitable as starting materials to prepare

• determination of the amount of product and/or starting material in the crude mixture by 1H NMR spectroscopy was conducted by adding 1 equiv of trichloroethylene as calibration compound after diluting the crude mixture in CDCl3. The amounts were estimated by comparing the integral value of the product C3–H

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

• substituent and an N-alkyl group (considering that N-aryl nitrophenyl-substituted compound 10o was obtained in a respectable 91% yield). The structures of compounds 10a–s were unequivocally confirmed by 1H and 13C NMR spectroscopy (paying a particular attention to the appearance of the C=N2 signal in the

• ). Using more reactive (electron-rich) arenes results in lower diastereoselectivity and regiospecificity of the reaction (cf. 9q, 9v, and 9w). The structure and the initially anticipated trans-configuration of the products 9 was unequivocally confirmed by 1H and 13C NMR spectroscopy as well as, in the case

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• acknowledge the Central Instrumentation Facilities of BITS-Pilani, Pilani campus and K. K. Birla Goa campus, and Central Analytical Laboratory of BITS-Pilani, Hyderabad campus for NMR spectroscopy.

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• which oxalyl chloride was added at room temperature, and then reacted with aluminium trichloride at 0 °C. The resulting material was not soluble in cold dichloromethane/chloroform, but was found to be sufficiently soluble in hot chlorinated solvents. NMR spectroscopy in deuterated DMSO indicated that

• refluxed overnight [43]. The result was a dark violet/black material, which was not soluble in common organic solvents, thereby preventing NMR spectroscopy. Also, sublimation failed. However, the mass could be measured with MALDI mass spectrometry, and microanalysis results matched the theoretical values

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• the reaction. Unless stated otherwise, a purity of at least 95% was obtained for all the compounds by means of chromatography or recrystallization and this level of purity was established by TLC, LC–MS, and NMR spectroscopy. General protocol for the experiments described in Table 1, description of

Mechanochemical halogenation of unsymmetrically substituted azobenzenes

• Dajana Barišić,
• Mario Pajić,
• Ivan Halasz,
• Darko Babić and
• Manda Ćurić

Beilstein J. Org. Chem. 2022, 18, 680–687, doi:10.3762/bjoc.18.69

• reaction dynamics and characterization of the products was achieved by in situ Raman and ex situ NMR spectroscopy and PXRD analysis. A strong influence of the different 4,4’-substituents of azobenzene on the halogenation time and mechanism was found. Keywords: azo compounds; halogenation; mechanochemistry

• % yields, respectively, as confirmed by NMR spectroscopy (Figures S82–S91 in Supporting Information File 1). Additional support for the formation of succinimide products was provided by the molecular structure of L4-III, resolved by single-crystal X-ray analysis (Figure 3 and Figure S33 and Table S1 in

• (Table 2, entries 11 and 12). Unlike bromination, iodination of L6–8 with NIS resulted in a mixture of the mono- and diiodinated products at the ortho positions of one or both phenyl rings (LnI-IV and LnI-V, Scheme 2 and Table 2, entries 10–12), as confirmed by NMR spectroscopy (Figures S104–S130 in

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

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

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• compound 16 must exclude the occurrence of ESIPT-promoted photoprocesses. Therefore, it could be expected that UV irradiation of such a compound would lead only to 6π-electrocyclization of the 1,3,5-hexatriene system. Initially, the photochemical behavior of pyrazole 16 was studied using NMR spectroscopy

• communication we have described for the first time the phototransformation of the 3-hydroxypyran-4-one fragment with the isolation of the resulting substituted α-hydroxy-1,2-diketone in pure form. The structure of the obtained compound 14a was confirmed using 1H, 13C NMR spectroscopy as well as 2D NMR

• approach allowed the synthesis of a variety of substituted α-hydroxy-1,2-diketone 14, however, according to NMR spectroscopy, the purity of the synthesized compounds 14b–l did not exceed 80%. Attempts to carry out additional purification of these products using recrystallization or chromatographic methods

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• compound, 10-imino-2-methylpyrido[1,2-a]pyrrolo[3,4-d]pyrimidine-1,3(2H,10H)-dione (3a), in 97% yield. The chemical structure of product 3a was confirmed by 1H and 13C NMR spectroscopy (Figures S1 and S2 in Supporting Information File 1) and was obtained via the following reaction mechanism: nucleophilic

• 13C NMR spectroscopy (Figures S5 and S6 in Supporting Information File 1). Similarly, the reaction of 1 with 2-aminopyridine derivatives 2d–g bearing electron-withdrawing groups, except for the nitro-group containing substrate 2h, at position 5 of the pyridine ring, afforded N-methyl-4-((pyridin-2-yl

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• molecule overexpressed in cancer cells, through host–guest competitive substitution since TBTQ-CB6 has a stronger binding affinity toward SM than MV and DOX. The host–guest interactions of the complexes of TBTQ-CB6 with MV, DOX and SM were investigated by NMR spectroscopy and fluorescence spectroscopy. The

• competitive guest to control the release of MV and DOX. The structures of the target molecule TBTQ-CB6 and its precursors were characterized by NMR spectroscopy and mass spectrometry. The host–guest chemistry of TBTQ-CB6MV, TBTQ-CB6DOX and TBTQ-CB6SM was investigated by NMR spectroscopy and fluorescence

• synthesized compounds were fully characterized by 1H and 13C NMR spectroscopy and mass spectrometry (see Supporting Information File 1) and the data were found to be consistent with the proposed structures. Host–guest complexation of TBTQ-CB6 with dimethyl viologen (MV). The host–guest complexation between

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• thread also leads to a desymmetrization of the BINOL-based macrocycle (loss of C2 symmetry), as seen by 13C NMR spectroscopy. Stoddart and co-workers also used their π–π-recognition approach for the synthesis of BINOL-containing cationic catenanes [47][48]. They employed BINOL-based macrocycles

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• the formation of the 2-cyano- and 2-(4-tert-butylphenylthio) derivatives 4 and 5 in 65% and 77% yield, respectively. Finally, compound 5 in the reaction with oxone furnished 2-(4-tert-butylphenylsulfonyl) derivative 6 in reasonable 68% yield. 1H and 13C NMR spectroscopy and HRMS were employed to

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• polarity on the keto–enol equilibrium of the 1,3-diketones, which influences the results of the [3 + 2] cycloaddition reactions under mild basic conditions, via nuclear magnetic resonance (NMR) spectroscopy. The 1H NMR spectra of 1-phenyl-1,3-butanedione (2a) in CDCl3 and in methanol-d4 indicated that the

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• model substrates for our investigation (Table 1). Completion of the reaction was monitored by IR and 1H NMR spectroscopy by the disappearance of the bands at 2196–2212 cm–1 (–C≡C–Br) and signals of the bromopropargylic alcohol 1a, respectively. Under the conditions previously used [18][19][20][21] for

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• ]heptadien-2-yltrifluoroborate (3) in 72% yield (Scheme 1), which was obtained in sufficient purity (>97%), as indicated by 1H NMR spectroscopy; however, satisfactory elemental analysis data could not be obtained for this product. The parent bicyclo[2.2.1]heptadien-2-ylboronic acid could not be obtained at

• the neighboring methyl group at the reaction center. The novel compounds 2a, 2b, and 3 were identified and characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC), melting point, and elemental analysis. In addition, the structure of product 2b was supported by high resolution mass spectrometry

• most of them tend to decompose slowly in solution or during chromatographic work-up [31][34]. The novel compounds 5b–j were identified and fully characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC); however, correct elemental analysis was not obtained in the case of the less-stable products 5d