NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• students, examples with combined 1D, 2D, and even some heteronuclear spectra can be used [42]. Here, one set including eight examples consisting exclusively of one-dimensional 1H and 13C NMR spectra and eight additional exercises including a combination of 1H, 13C, COSY, HSQC, and HMBC experiments provide

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• effect on the yield of the final compounds 3 observed. The structures of compounds 3a–u were confirmed by IR, 1H and 13C NMR spectroscopy (Figures S1‒S44 in Supporting Information File 1) as well as by high-resolution mass spectrometry (HRMS). X-ray data obtained for compound 3g gave us final proof of

• , 0.5 mmol; 1,4-dioxane (2 mL)) as a colorless powder; mp 225–226 °C; 1H NMR (400 MHz, DMSO-d6) δ 3.16 (s, 3H), 3.21 (s, 3H), 5.08 (s, 1H), 5.46 (s, 2H), 6.52 (s, 1H), 6.53 (s, 1H), 7.19 (br. s, 2H), 7.25–7.39 (m, 5H); 13C NMR (101 MHz, DMSO-d6) δ 27.1, 29.8, 48.4, 87.4, 120.9, 127.4, 127.6, 128.5

• NMR (400 MHz, DMSO-d6) δ 5.48 (s, 2H), 6.68 (s, 1H), 6.69 (s, 1H), 7.10 (d, J = 3.9 Hz, 1H), 7.24 (d, J = 6.9 Hz, 2H), 7.28–7.38 (m, 3H), 7.43 (d, J = 3.9 Hz, 1H), 8.42 (br. s, 1H), 9.15 (br. s, 1H); 13C NMR (101 MHz, DMSO-d6) δ 48.5, 112.6, 121.2, 127.2, 127.6, 128.5, 135.7, 138.8, 143.6, 153.5

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• -chelate. In fact, the following convincing peaks were found in the NMR spectra: a singlet at 6.11 ppm, along with a quartet at 4.68 ppm (1H NMR spectrum), a peak at 83.3 ppm (13C NMR spectrum) and a singlet at −139.1 ppm (19F NMR spectrum) [109]. A simple washing with distilled water gave the

• In order to have an idea of the current efficiency in the electrogeneration of BF3 in BMIm-BF4 (a monoelectronic process, Scheme 1), we tried to quantitatively capture the electrogenerated BF3 with a tertiary base just at the end of the electrolysis. By a comparison between the 13C NMR peaks of the

• anolyte and the mixture was kept under stirring at room temperature for 30 min. Then, the neat anolyte was analysed by NMR (19F and 13C). The 19F NMR spectrum showed a new peak at −148.7 ppm and, to our great astonishment, we found only one set of signals in the 13C NMR spectrum (55.0, 42.8, 17.4, 16.0

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• cyclic (alkyl)(amino) or mesoionic carbenes (CAACs or MICs) onto carbon disulfide. Nine novel compounds were isolated and fully characterized by 1H and 13C NMR, FTIR, and HRMS techniques. Moreover, the molecular structures of two CAAC·CS2 and two MIC·CS2 betaines were determined by X-ray diffraction

• on 13C NMR spectroscopy (see below). We suspect that deleterious hydrophilic effects caused the subsequent decomposition of the CAAC·CS2 and MIC·CS2 zwitterions when an aqueous work-up was applied. Structural analysis Several analytical techniques were employed to characterize the nine aldiminium and

• significantly altered by the nature of the adjacent heterocycle, in line with a lack of electronic communication between these two moieties, as further discussed below. Contrastingly, the 13C NMR resonance for the carbenoid center of all the reagents and products used in this study was clearly affected by the

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• spiro[indoline-3,5'-[1,2]diazepine]-6'-carboxylates 5a–g in 63–77% yields (Scheme 3). The substituents on both substrates also showed little effect on the yields. The chemical structures were fully characterized by HRMS, IR, 1H and 13C NMR spectra. For demonstrating the synthetic value of this protocol

• (d, J = 8.0 Hz, 1H, ArH), 4.95–4.90 (m, 2H, CH2), 3.47 (d, J = 14.0 Hz, 1H, CH), 3.24 (d, J = 14.0 Hz, 1H, CH), 2.16 (s, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3) δ 173.8, 170.9, 159.6, 139.6, 138.4, 136.2, 135.2, 133.3, 133.2, 131.8, 130.7, 130.3, 130.0, 129.2, 128.9, 128.4, 127.9, 127.8, 127.4, 127.3

• –6.85 (m, 1H, ArH), 6.70 (d, J = 8.4 Hz, 1H, ArH), 5.02 (s, 2H, CH2), 3.65 (s, 3H, OCH3), 3.49 (d, J = 13.6 Hz, 1H, CH), 3.10 (d, J = 13.6 Hz, 1H, CH) ppm; 13C NMR (100 MHz, CDCl3) δ 176.3, 171.3, 165.8, 160.6, 141.1, 137.3, 135.9, 135.5, 133.8, 131.6, 130.6, 129.7, 128.9, 128.5, 128.4, 127.9, 127.8

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• purification. Thin-layer chromatography (TLC) was performed using Merck Silica gel 60 F254 plates and visualized by UV (254 nm) fluorescence. Zeochem silica gel (ZEOprep 60/35–70 microns – SI23501) was used for column chromatography. 1H and 13C NMR spectra were recorded on a Bruker 400 spectrometer at 400 and

• (0.90 g, 89%) was obtained as bright yellow powder. Mp > 200 °C; 1H NMR (400 MHz, CDCl3) 8.11 (d, J = 1.9 Hz, 4H), 7.87–7.76 (m, 4H), 7.72 (d, J = 8.9 Hz, 4H), 7.49 (dd, J = 8.8, 1.9 Hz, 4H), 1.47 (s, 36H), 0.31 (d, J = 1.0 Hz, 9H); 13C NMR (101 MHz, CDCl3) 163.16, 154.51, 146.43, 136.98, 132.85, 132.58

• ) 8.11 (dd, J = 2.0, 0.6 Hz, 8H), 7.90 (s, 8H), 7.73 (dd, J = 8.8, 0.5 Hz, 8H), 7.49 (dd, J = 8.8, 2.0 Hz, 8H), 1.46 (s, 72H); 13C NMR (101 MHz, CDCl3) 162.83, 154.53, 154.50, 146.56, 146.52, 136.96, 133.59, 133.50, 133.11, 129.93, 129.72, 126.17, 125.78, 125.76, 125.54, 124.23, 124.21, 116.61, 114.01

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

• properties indicated that the composition of thienothiophene, triphenylamine, and boron is a highly suitable combination for fluorescent organic electronics in display technology. Experimental General methods 1H and 13C NMR spectra were recorded on a Varian model NMR spectrometer (500 and 126 MHz) and

• = 8.7 Hz, 5H), 7.20 (d, J = 8.7 Hz, 2H), 7.13 (d, J = 7.6 Hz, 4H), 7.05 (t, J = 7.3 Hz, 2H), 6.95 (d, J = 8.7 Hz, 2H), 6.92 (d, J = 8.8 Hz, 2H), 3.86 (s, 3H); 13C NMR (126 MHz, CDCl3) δ 158.89, 147.36, 147.17, 142.04, 139.51, 135.73, 130.12, 129.87, 129.29, 128.34, 127.96, 125.86, 124.80, 123.24, 122.53

• ), 2.17 (s, 12H); 13C NMR (126 MHz, CDCl3) δ 158.92, 153.46, 151.26, 147.60, 147.20, 143.95, 141.05, 140.90, 138.50, 137.96, 132.59, 130.25, 129.86, 129.49, 129.33, 128.14, 127.85, 127.57, 125.01, 123.45, 122.08, 114.12, 55.23, 23.54, 21.22. Absorption and emission of DMB-TT-TPA (8) in THF. Figure 1 was

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

• -tosylimines. Experimental General method: All reagents and solvents were purchased from Sigma-Aldrich, Fisher Scientific, or Acros Organics and were used without further purification. 1H NMR (400 MHz), 13C NMR (100 MHz), and 19F NMR (376 MHz) spectra were recorded on a Bruker 400, Ultra Shield high

• -performance digital FT-NMR spectrometer. Data for 1H NMR, 13C NMR, and 19F NMR are reported as follows: chemical shift (δ, ppm), multiplicity (s = singlet, d = doublet, t = triplet, m = multiplet, q= quartet, bs = broad singlet, dd = doublet of doublets, td = triplet of doublets, qd = quartet of doublets

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• (m, 1H), 2.86 (m, 1H), 2.82 (m, 1H), 2.41 (bs, 1H), 1.69 (m, 1H), 1.68 (m, 2H), 1.54 (m, 1H), 0.85 (m, 1H); 13C NMR (methanol-d4, 150 MHz, 295 K) δ 185.7, 182.1, 170.4, 164.8, 158.3, 147.6, 145.3, 144.6, 142.5, 142.3, 133.9 (q, 2JC,F = 33.4 Hz), 131.7, 129.7, 124.5 (q, 1JC,F = 272.0 Hz), 123.9, 120.0

• (m, 2H), 3.69–3.59 (m, 1H), 3.56–3.47 (m, 1H), 3.30–3.27 (m, overlapped, 1H), 2.99 (s, 1H), 2.93–2.86 (m, 1H), 2.86 (s, 1H), 2.84–2.76 (m, 1H), 2.43–2.37 (m, 1H), 1.70–1.61 (m, overlapped, 4H), 1.27 (m, 1H), 0.73–0.66 (m, 1H) ppm; 13C NMR (126 MHz, MeOH-d4, 298 K) δ 186.4, 182.8, 170.9, 165.9, 159.7

• , 2H), 6.30 (br s, 1H), 5.70 (m, 1H), 5.21–4.90 (m, 2H), 4.45 (m, 2H), 4.06–3.88 (m, overlapped, 10H), 3.76–3.69 (m, 2H), 3.61–3.19 (m, 2H), 3.09–2.65 (m, 2H), 1.93–1.61 (m, overlapped, 7H), 1.52–1.11 (m, overlapped, 94H), 0.88 (t, J = 7.0 Hz, 9H,) ppm; 13C NMR (75 MHz, CDCl3, 318 K) δ 185.4, 180.3

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• –7.04 (overlapped signals, 8H, HAr), 6.75 (d, 3J = 8.9 Hz, 2H, HAr), 3.94 (t, 3J = 6.3 Hz, 2H, OCH2), 3.43 (t, 3J = 6.8 Hz, 2H, CH2Br), 1.93 (qv, 3J = 6.9 Hz, 2H, CH2), 1.83–1.77 (m, 2H, CH2), 1.65–1.58 (m, 2H, CH2), 1.30 (s, 27H, C(CH3)3) ppm; 13C NMR (CDCl3, 150 MHz) δ 156.9, 148.5, 144.3, 139.7

• (1.90 g, 92%); mp 72–73 °C, Rf = 0.47 (silica, ethyl acetate/petroleum ether = 1:3);1H NMR (CDCl3, 600 MHz) δ 7.49 (s, 1H, HAr), 7.42–7.36 (overlapped signals, 3H, HAr), 6.93 (s, 8H, HAr), 5.03 (s, 4H, CH2), 4.65 (d, 4H, 4J= 2.3 Hz, CH2(propargyl)), 2.52 (t, 4J = 2.3 Hz, CH2(propargyl)) ppm; 13C NMR

• = 6.4 Hz, 4H, CH2), 3.73 (t, 3J = 5.1 Hz, 2H, CH2), 3.70–3.64 (overlapped signals, 6H, CH2), 3.60–3.51 (overlapped signals, 12H, CH2), 1.75 (qv, 3J = 7.6 Hz, 4H, CH2), 1.64 (qv, 3J = 7.3 Hz, 4H, CH2), 1.35–1.28 (overlapped signals, 58H, CH2, C(CH3)3) ppm; 13C NMR (CD2Cl2, 150 MHz) δ 158.6, 158.57, 157.4

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• C11H18N12 for bis-pyrazole 6. According to NMR spectroscopic data, the amount of bis-pyrazole 6 in the crude product formed under above conditions was about 18 mol %. The structure of macrocycle 5 was confirmed by comparing its 1H and 13C NMR spectra with those reported in ref. [40]. It should be noted that

• (1 h instead of 5 h). The precipitated compound 8 was isolated by filtration in a 96% yield (Scheme 4). Previously, the structure of 8 was assigned based on 1H and 13C NMR spectroscopic data [40]. However, these data are insufficient to distinguish compound 8 and its isomer 9 resulting from a Dimroth

• rearrangement that is known to proceed in 3-substituted 4-iminopyrimidine systems [40][45][46][47]. Our analysis of 1H, 13C NMR, and 2D NMR spectra (DMSO-d6 solution) of the prepared product confirmed its structure as compound 8. For example, the 1H,13C-HMBC spectrum showed correlation of the NH2 protons with

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• and hdz-NO2 (Figure 5A and 5B, respectively). 13C NMR and 2D homonuclear (COSY) and heteronuclear (13C,1H-HSQC and HMBC) experiments were employed for the full characterization of these hydrazones, and the spectra can be seen in Supporting Information File 1, Figures S5–S12. Both compounds exhibit

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• )diboron catalyzed by Pd(dpf)Cl2/KOAc. Finally, TPECNz was obtained as red solid in a reasonable yield by a Suzuki-type cross-coupling reaction between 3 and 4,9-dibromonaphtho[2,3-c][1,2,5]thiadiazole. The chemical structure and purity of compound 3 were verified by 1H NMR, 13C NMR, and high-resolution

• purchased from commercial resources and used without further purification. 1H NMR and 13C NMR spectra were recorded with a Bruker AVANCE III HD 600 (600 MHz for 1H and 151 MHz for 13C) using CDCl3 as a solvent containing TMS as an internal standard. High-resolution mass spectrometry (HRMS) analysis was

• chromatography over silica gel eluting with CH2Cl2/hexane 1:4 to give white solids (2.11 g, 87%). 1H NMR (600 MHz, CDCl3) δ 8.12 (d, J = 7.7 Hz, 2H), 7.40 (t, J = 7.8 Hz, 2H), 7.34 (d, J = 8.2 Hz, 2H), 7.28 (t, J = 8.0 Hz, 4H), 7.24 (d, J = 8.1 Hz, 2H), 7.21–7.07 (m, 15H); 13C NMR (151 MHz, CDCl3) δ 143.55

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• [34]. In the case of molecules with aryl Y-substituents – 1b2 and 1g2 – the room-temperature 1H and 13C NMR spectra (see Supporting Information File 1, Figures S2, S26 and S27, and reference [26]) display more resonances than expected based on the highest symmetry possible for the molecule indicating

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• adding a methanol/water mixture; thus, no lengthy purification steps were required for any of the syntheses. Yields of 52.4%, 80.2%, 58.1%, and 68.3% were obtained for PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-B, respectively. All compounds were structurally characterized using 1H NMR spectroscopy, 13C

• NMR spectroscopy, mass spectrometry, and elemental analysis. See Supporting Information File 1 for full synthetic and characterization details. Optical properties Using UV–visible spectroscopy, the optical properties for PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-FB in both solution and film form were

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• of X-ray structure data for compound 8. Supporting Information File 11: Copies of 1H and 13C NMR spectra of all purified novel compounds. Supporting Information File 12: Chrystallographic information file (cif) of X-ray structure for compound 8. Acknowledgements We acknowledge Prof. Dasan Thamattoor

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

• the ethyl acetate fraction (Figure 1). The structures of known compounds 5–7 were identified based on 1H and 13C NMR data [2][3][10]. Breynin J (1) was isolated as an amorphous, colorless powder. The HRESIMS spectrum exhibited a sodium adduct ion peak at m/z 1107.3177, consistent with a molecular

• . In addition, signals corresponding to a p-hydroxybenzoate group [δH 8.02 (d, J = 8.9 Hz, 2H, H-21, 25), 6.94 (d, J = 8.9 Hz, 2H, H-22, 24)] were observed. The 13C NMR spectrum (Table 1) suggested the presence of a breynogenin-α-S-oxide moiety, similar to that in breynins B, D, G, and I [2], with the

• aglycone of 2 also consisted of a breynogenin-S-oxide moiety. However, a comparison of the 1H and 13C NMR data for the aglycones of 1 and 2 revealed markedly different tetrahydrothiophene signals [for 2, δC 61.7 (C-2), 87.4 (C-3), 39.9 (C-4), 62.3 (C-17)] (Table 1). According to previous literature [2

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• (d, 2.0 Hz, 1H each), and at δH 7.57 and 6.62 (d, 1.0 Hz, 1H each), in addition to a singlet signal at δH 2.71 (s, CH3, 3H). The alternariol skeleton was further confirmed by the 13C NMR and HSQC spectra (Figures S10 and S11 in Supporting Information File 1), in conjunction with the HMBC spectrum

• overlapping at δH 2.28 due to two acetyl groups, which showed strong HMBC cross peaks with the carbonyl carbon signals at δH 169.0. The structure of 2 was fully assigned by using the 13C NMR spectrum which displayed sixteen carbon signals sorted into three methyl signals of which two overlapping ones at δC

• /USA) 500 MHz Avance III spectrometer with a BBFO (plus) Smart Probe (1H NMR: 500 MHz and 13C NMR: 125 MHz). Chemical shifts (δ) were reported in ppm using tetramethylsilane (TMS) (Sigma-Aldrich) as an internal standard, while coupling constants (J) were measured in hertz (Hz). Optical rotations were

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• . Proposed mechanism. Scale-up experiment. Optimization of reaction conditions.a Supporting Information Supporting Information File 2: General information, experimental procedures for all the substrates and intermediates, characterization data, and NMR spectra (1H, 19F, and 13C NMR). Funding Research

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• -Hydroxymethylfurfurylidene)-2-thioxothiazolidin-4-one (3j). ochre yellow solid obtained after 1 h at 60 °C in 36% yield (two-step yield). Mp 149 °C; 1H NMR (400 MHz, DMSO-d6) δ (ppm) 4.49 (s, 2H), 5.52 (br s, 1H, OH), 6.58 (d, J = 3.6 Hz, 1H), 7.11 (d, J = 3.6 Hz, 1H), 7.44 (s, 1H, =CH), 13.62 (br s, 1H, NH); 13C NMR (100

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• ) ppm; 13C NMR (100 MHz, DMSO-d6, T = 298 K) δ 152.0, 124.6, 123.3, 102.6, 43.7, 37.1, 30.7, 25.8, 22.8 ppm. 1:1 Complex of R[4]A with diethylamine: 68% yield; white solid; 1H NMR (400 MHz, DMSO-d6, T = 298 K) δ 7.16 (s, 4H, PhCH), 6.10 (s, 4H, PhCH), 5.6–3.6 (br s, 8H, OH), 4.34 (t, J = 7.70 Hz, 4H, CH

• , 4H, PhH), 4.43 (m, 4H, CH), 3.42 (q, J = 6.97 Hz, 2H, NCH2CH3), 3.41 (q, J = 6.97 Hz, 2H, NCH2CH3), 2.08 (m, 8H, CH2), 1.47 (m, 4H, CH), 1.24 (m, 3H, NCH2CH3), 0.97 (t, J = 6.60 Hz, 24H, CH3), 0.22 (br t, 3H, NCH2CH3) ppm; 13C NMR (100 MHz, DMSO-d6, T = 298 K) δ 151.8, 124.9, 123.2, 102.5, 42.9, 42.7

• , 2H, N(CH2)2(CH2)2), 1.49 (m, 4H, CH), 0.99 (t, J = 6.24 Hz, 24H, CH3), −0.7 (m, 4H, N(CH2)2(CH2)2) ppm; 13C NMR (100 MHz, DMSO-d6, T = 298 K) δ 152.0, 124.3 123.3, 102.7, 45.7, 42.5, 31.6, 25.7, 24.6, 22.7 ppm. 1:1 Complex of R[4]A with piperidine: 78% yield; white solid; 1H NMR (400 MHz, DMSO-d6, T

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• to the 13C NMR spectra, the largest downfield shift was observed for the carbonyl carbon С1, with ∆δ = 17.7–21.1 ppm, showing a substantial degree of protonation of the carbonyl group in TfOH. The tendencies are the same for the protonation of enones 2a,c,d,m leading to cations Ba,c,d,m (Table 2

• ). Thus, in the 1H NMR spectra, downfield shifts of vinyl protons H2 and H3 upon protonation were 0.50–0.61 and 0.41–0.54 ppm, respectively. In the 13C NMR spectra, ∆δ values for carbons С1 and С3 were 12.7–21.3 and 6.0–13.4 ppm, respectively. The NMR data revealed that the positive charge in the O

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• ppm) for 1H NMR and the 13C signal of C6D6 (δ = 128.06 ppm) for 13C NMR [39]. Coupling constants are given in Hz. IR spectra were recorded on a Bruker α infrared spectrometer with a diamond ATR probehead. Peak intensities are given as s (strong), m (medium), w (weak) and br (broad). Optical rotations

• ; 13C NMR (126 MHz, D2O) δ 135.80 (Cq), 133.72 (Cq), 125.03 (d, 3JC,P = 8.5, CH), 124.26 (CH), 67.10 (d, 2JC,P = 5.6, CH2), 34.11 (CH2), 25.67 (CH2), 24.83 (CH3), 17.41 (CH3), 16.86 (CH3), 15.67 (CH3) ppm; 31P NMR (202 MHz, D2O) δ −7.90 (d, 2JP,P = 21.3), −10.40 (d, 2JP,P = 21.4) ppm; HRMS–TOF (m/z

• , 3JH,H = 6.8, 1H), 4.40 (d, 3JH,P = 5.9, 2H), 1.69 (m, 3H), 1.58 (dm, 3JH,H = 7.0, 3H) ppm; 13C NMR (126 MHz, D2O) δ 132.34 (d, 3JC,P = 8.0 Hz, Cq), 124.64 (CH), 64.18 (d, 2JC,P = 5.3, CH2), 20.52 (d, 4JC,P = 1.8, CH3), 12.62 (d, 5JC,P = 2.2, CH3) ppm; 31P NMR (202 MHz, D2O) δ −7.0 (d, 2JP,P = 21.2 Hz

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• compounds 5 in yields between 11–69% after chromatographic workup. The structures of the products were unambiguously confirmed by 1H and 13C NMR spectroscopy, as well as by mass spectrometry. Assuming that four new bonds are being formed in this one-pot process, the range of yield from 11 to 69% (after

• -trisubstitued indoles 8 in good yield (Scheme 4). The 1,2,3-trisubstitued indoles 8 were unambiguously confirmed by 1H and 13C NMR spectroscopy, as well as by mass spectrometry and elemental analysis. Miura et al. could show that 1-alkyl-2,3-diarylindoles constitute a class of blue-emissive indole derivatives

• ), 7.23–7.26 (m, 1H), 7.46–7.54 (m, 5H); 13C NMR (150 MHz, CDCl3) δ 1.9 (Cquat), 32.4 (CH3), 106.7 (CH), 110.8 (CH), 111.5 (CH), 128.6 (Cquat), 129.3, 130.9, 131.5 (Cquat), 134.5 (Cquat), 143.5 (Cquat), 160.0 (Cquat); IR (cm−1) ν̃: 604 (w), 619 (w), 662 (w), 689 (s), 733 (m), 756 (s), 789 (m), 860 (w

Correction: Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 1370–1371, doi:10.3762/bjoc.19.97

• HMBC correlations of H-2/C-1, C-3, C-4, C-8a, H-4/C-3, C-4a, C-5, C-8a, C-9, H-5/C-4, C-4a, C-6, C-7, C-8a, H-9/C-2, C-3, C-4, H-10/C-7, C-8, C-8a, H-11/C-6, and H-12/C-7. Table 1 provides the revised 1D 1H and 13C NMR data of compound 1. The structural revision of 1 also required recalculation of the

• compound 1 and key HMBC correlations. Recalculated and experimental ECD spectra of compound 1. Revised 1H (600 MHz) and 13C NMR (150 MHz) data of compound 1 (δ in ppm, J in Hz, methanol-d4).