Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• setup. The initial setup consisted of a heated glass column (i.d. 7 mm, length 7 cm), packed with K2CO3, through which a solution of acyl hydrazone and iodine were passed. It was anticipated that the larger excess of K2CO3 present in the packed bed reactor (when compared to batch mode), in addition to

• larger quantity of K2CO3. As a result of the increased volume of the reactor column (i.d. 15 mm, length 12 cm) a proportional increase in flow rate was necessary to maintain the residence time consistent with our small-scale experiments. Following reaction, the excess iodine must be quenched via a wash

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• absorption bands at 325 and 293 nm indicated the presence of a coumarin-type chromophore. The IR spectrum of 1 demonstrated absorption bands characteristic for an hydroxy group (3266 cm−1), α,β-unsaturated carbonyl group (1739 and 1701 cm−1), and an aromatic ring (1624 and 1457 cm−1). The 1H NMR spectrum of

• products generated by plant species from the genus Wikstroemia. Experimental General experimental procedures Optical rotations were measured with a Horiba SEPA-300 polarimeter. UV spectra were recorded using a Waters UV-2401A spectrophotometer equipped with a DAD and a 1 cm path length cell. Methanolic

• the solvent signals. Mass spectra were recorded on a VG Auto Spec-3000 instrument or an API QSTAR Pulsar 1 spectrometer. Semi-preparative HPLC was performed on an Agilent 1120 apparatus equipped with a UV detector and a Zorbax SB-C-18 (Agilent, 9.4 mm × 25 cm) column. Column chromatography was

Diametric calix[6]arene-based phosphine gold(I) cavitands

• Gabriele Giovanardi,
• Andrea Secchi,
• Arturo Arduini and
• Gianpiero Cera

Beilstein J. Org. Chem. 2022, 18, 190–196, doi:10.3762/bjoc.18.21

• atmosphere. Subsequently, a tip of spatula (micro spatula, Heyman type 16 cm) of AgSbF6 (≈2.0 mol %, ≈2 mg) was added along with 20 mg of 4 Å molecular sieves. The flask was covered with an aluminum foil and the mixture stirred for 5 minutes. Subsequently, 1a (0.2 mmol, 63.0 mg) was added and the reaction

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

• José G. Hernández,
• Karen J. Ardila-Fierro,
• Dajana Barišić and
• Hervé Geneste

Beilstein J. Org. Chem. 2022, 18, 182–189, doi:10.3762/bjoc.18.20

• performed in situ reaction monitoring of the milling process by Raman spectroscopy [32][33]. In an experiment milling 1c with NFSI (1 equiv) we observed the consumption of NFSI after ca. 30 min of milling as evidenced by a reduction in the intensity of the band at 1197 cm−1 of NFSI (Figure S3 in Supporting

• Information File 1). However, the very strong bands around 998 cm−1 (in-plane bending; phenyl ring), 1177 cm−1 (stretching; SO2), and 1583 cm−1 (stretching; phenyl ring) of NFSI and byproducts [(PhSO2)2NH [34], and (PhSO2)2NCH3], prevented the observation of the less Raman active fluorinated products 2c and

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• bare chitosan was carried out, and the spectrum exhibited characteristic peaks for the O–H and N–H stretching vibrations in the range of 3300–3400 cm−1 (Figure 1b). For the chitosan-supported nickel catalyst, the band around 3400 cm−1 became much sharper and stronger compared to bare chitosan (Figure

•  1a). The spectroscopic FTIR study revealed the interaction between the metal and the NH2 and OH groups of chitosan. In both spectra, the peaks around 1100, 1400, 1600, and 2900 cm−1 corresponded to the C–O, C–N, and N–H (bending) as well as to the C–H bonds of the chitosan moiety, respectively. The

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• ): pale brown powder; UV (MeOH) λmax nm (log ε): 201 (4.82) nm; IR (ATR) νmax: 3305, 2916, 2849, 1613, 1538, 1466 cm−1; 1H and 13C NMR, Table 1; HR–ESITOFMS (m/z): [M − H]− calcd for C33H60N5O8, 654.4447; found, 654.4449; [M + Na]+ calcd for C33H61N5O8Na, 678.4412; found, 678.4412. Tenacibactin L (2

• ): pale brown powder; UV (MeOH) λmax nm (log ε): 202 (4.21) nm; IR (ATR) νmax: 3306, 2916, 2849, 1613, 1538, 1466 cm−1; 1H and 13C NMR, Table 2; HR–ESITOFMS (m/z): [M − H]− calcd for C33H60N5O8, 654.4447; found, 654.4445; [M + Na]+ calcd for C33H61N5O8Na, 678.4412; found, 678.4410. Tenacibactin M (3

• ): pale brown powder; UV (MeOH) λmax nm (log ε): 202 (4.35) nm; IR (ATR) νmax: 3306, 2916, 2849, 1613, 1538, 1466 cm−1; 1H and 13C NMR, Table 2; HR–ESITOFMS (m/z): [M − H]− calcd for C33H62N5O8, 6546.4604; found, 656.4604; [M + Na]+ calcd for C33H63N5O8Na, 680.4569; found, 680.4567. Bioassays

Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks

• Jolita Bruzgulienė,
• Greta Račkauskienė,
• Aurimas Bieliauskas,
• Vaida Milišiūnaitė,
• Miglė Dagilienė,
• Gita Matulevičiūtė,
• Vytas Martynaitis,
• Sonata Krikštolaitytė,
• Frank A. Sløk and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2022, 18, 102–109, doi:10.3762/bjoc.18.11

• structural assignment of regiospecific compound 4a was readily deduced via detailed spectral data analysis. The IR spectrum of 4a contained characteristic absorption bands such as 1723 (C=O, ester), and 1687 (C=O, Boc) cm−1. The 1H NMR spectrum of compound 4a revealed a characteristic resonance for the Boc

Efficient synthesis of ethyl 2-(oxazolin-2-yl)alkanoates via ethoxycarbonylketene-induced electrophilic ring expansion of aziridines

• Yelong Lei and
• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 70–76, doi:10.3762/bjoc.18.6

• , and the chemical shifts (δ) are reported in parts per million (ppm). All coupling constants (J) in 1H NMR are absolute values given in hertz (Hz) with peaks labeled as singlet (s), broad singlet (brs), doublet (d), triplet (t), quartet (q), and multiplet (m). IR spectra (KBr pellets, v [cm−1]) were

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• determined to be C10H16O2 on the basis of its NMR and HR–ESI–TOFMS data (m/z 191.1044 [M + Na]+, Δ + 0.1 mmu). Three degrees of unsaturation, calculated from the molecular formula, a UV absorption maximum at 264 nm, and IR absorption bands at 1679 and 2800–3200 cm−1, suggested dienone and hydroxy

• at 3310 and 1656 cm–1 suggested the presence of OH/NH and carbonyl groups. 1H, 13C, and HSQC spectra (Table 3) revealed the composition of this molecule to be two shielded carbonyls, five other sp2 nonprotonated carbons, five sp2 methines, one sp3 methine, two sp3 methylenes, three singlet methyls

• extract 0.5%, and glucose 0.2% (pH 7.3) solidified by agar 2%, was inoculated into test tubes (inner diameter, 15 mm; length 16.5 cm) each containing 5 mL of YG seed medium consisting of glucose 1% and yeast extract 1% (pH 7.0). The tubes were shaken at 260 strokes/min at 28 °C for 3 days (TC-500R

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• %, with Commission Internationale de l’Éclairage coordinate of (0.22, 0.47), at 1 mA cm−2. Keywords: blue emitters; dimer; indolocarbazole; orientation; outcoupling effect; solution-processed OLEDs; TADF emitters; triazine; Introduction Organic thermally activated delayed fluorescence (TADF) materials

• mA cm−2. The 20 wt % ICzTRZ-based OLEDs exhibited a slightly higher EQEmax of 11.6% and blue-shifted emission with λEL of 485 nm. This result is consistent with that of the photophysical measurements for 20 wt % TADF emitter:CzSi films (ΦPL = 57% and λPL = 488 nm for DICzTRZ, ΦPL = 63% and λPL = 475

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• superposition of the spectra recorded for Q[8] (a) and CPE (b), and there was no interaction. When comparing (c) and (d), the C–H stretching vibration peak was observed at 3100 cm−1 and the C=C skeleton vibration peaks of the benzene ring of CPE were observed at 1603, 1520 and 1413 cm−1; the bending vibration

• peaks of the O–H bonds were observed at 1106 and 1066 cm−1. The nitro-symmetric tensile vibration peak observed at 1503 cm−1 and the nitro-asymmetric tensile vibration peak at 1320 cm−1 disappeared in the spectrum (d). At the same time, the fingerprint region peak of the benzene ring observed from 500

• to 900 cm−1 disappeared or weakened. Therefore, it can be inferred that CPE interacts with Q[8]. The effect of Q[8] on the properties of CPE Stability analysis The stability of CPE and CPE@Q[8] in artificial gastrointestinal juice was investigated using UV–is spectroscopy. Figure 7A shows the

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• the IR spectra (recorded using a Nicolet 510 P-FT) are listed and wave numbers are given in cm−1. Nuclear magnetic resonance spectra and decoupling experiments were determined at 250 MHz on a Q.E 300 instrument, at 300 MHz on a Bruker Avance AC-300 and at 500 MHz on a Bruker AM500 spectrometer as

• ), 129.4 (2C), 129,2 (4C), 128.8 (2C), 128.2 (4C), 127.7 (2C), 127.5 (2C), 73.1 (2C), 63.1 (2C), 52.9 (2C), 51.5 (2C), 45.5 (2C), 40.2 (2C), 36.4 (2C); IR (cm−1) νmax: 3027, 2948, 1738, 1587, 1492, 1398, 1359, 1244, 1101, 1023, 704; ESIMS m/z: 1234 (21), 1233 (30), 1232 (47), 1231 (M+, 64), 1230 (100

• ), 72.8 (2C), 60.6 (2C), 55.8 (2C), 55.1 (2C), 52.7 (2C), 51.5 (2C), 45.8 (2C), 40.4 (2C), 36.8 (2C); IR (cm−1) νmax: 3023, 2947, 1735, 1587, 1496, 1396, 1361, 1268, 1205, 1122, 1024, 703; ESIMS m/z: 1216 (5), 1215 (25), 1214 (M+, 38), 1213 (67), 1212 (100); anal. calcd for C62H66N4NiO14S2: C, 61.3; H

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

• VERTEX 70 spectrophotometer with Platinum ATR accessory (diamond crystal) in the 4000–400 cm−1 region. High-resolution mass spectra (HRMS) were obtained for all compounds on a hybrid high-resolution and high-accuracy (5 μL/L) micro Q-TOF mass spectrometer (Bruker Scientific®, Billerica, MA, USA) at the

• 660 nm red light diode laser positioned 2.0 cm from the sample (TheraLase DMC, São Carlos, SP, Brazil) with an average power of 100 mW, during 10 min (irradiation intervals every 30 s). All spectra are provided in Supporting Information File 1 (Figures S8–S17). Synthetic procedures General procedure

• ), 123.36 (q, J = 274.0 Hz, CF3), 121.85 (C-4a), 119.64 (q, J = 5.3 Hz, C-3), 119.29 (C6H4OH), 119.01 (C6H4OH), 117.37 (C6H4OH), 114.75 (t, J = 2.2 Hz, C-5), 25.34 (CH3) ppm; 19F NMR (565 MHz, CDCl3) δ −61,71 (CF3) ppm; FTIR (ATR) ν: 3061 (ν OH), 1627 (ν CH=N), 1118 (ν C-O) cm−1; HRMS–ESI (m/z): [M + H

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• Finnigan LTQ FT Ultra Fourier Transform Ion Cyclotron Resonance device at 250 °C for ESI. IR spectra were recorded on a Perkin Elmer FT-IR Paragon 1000 instrument as neat materials. Absorption bands were reported in wave numbers (cm−1), obtained on a ATR PRO450-S accessory (Jasco). Melting points were

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• , 1700, 1162 cm−1. 1H NMR (300 MHz, CDCl3) δ 3.98–3.84 (m, 2H); 3.68–3.57 (m, 1H), 3.53–3.35 (m, 2H), 2.13–2.03 (m, 1H), 1.99–1.81 (m, 3H), 1,47 (s, 9H) ppm. (S)-tert-Butyl 2-(isocyanatomethyl)pyrrolidine-1-carboxylate (3b) BTC (0.33 g, 1.11 mmol) was dissolved in dry THF (10 mL) and the solution was

• , 2973, 1685, 1161, 1107, 1038 cm−1; HRMS (m/z): [M + H]+ calcd for C15H29N3O3S2, 364.1723; found, 364.1725; [M + Na]+ calcd, 386.1543; found, 386.1544. (S)-tert-Butyl 2-((3-((S)-tert-butylsulfinyl)thioureido)methyl)pyrrolidine-1-carboxylate ((S,S)-5a) +30.5 (c 0.5, MeOH); 1H NMR (600 MHz, CDCl3) δ 9.22

• , 2973, 1653, 1159, 1237, 1058 cm−1; HRMS (m/z): [M + Na]+ calcd for C15H29N3O3S2, 386.1543; found, 386.1543; [M + H]+ calcd, 364.1729; found, 364.1722. General procedure for the preparation of N-sulfinylurea pre-catalysts (S,R)-5b and ((S,S)-5b) A stirred solution of (R)-tert-butanesulfinamide or (S

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• =C (1570–1605 cm−1) and C=O stretching (1640–1710 cm−1) region of the infrared spectra of P1 recorded during heating. These regions are specific to the perylene moieties in the polymers and, therefore, allow a direct observation of the π–π interactions in the polymer. Both the C=C and C=O vibrations

• are sensitive to the electron density in the perylene systems, which changes depending on the strength of π–π interactions [28][29][30]. During heating, the C=C stretching vibrations located at 1578 and 1594 cm−1 show opposite behavior regarding their wavenumber position: While the band at 1578 cm−1

• shifts to slightly higher wavenumbers (indicating more electron density in the perylene rings), the band at 1594 cm−1 shifts to slightly lower frequencies (indicating less electron density in the perylene rings). This seemingly counterintuitive behavior can be explained by the fact that the perylene

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

• azide groups decomposed at higher temperature. The IR spectrum of the cross-linked polymer further demonstrates the formation of a triazole ring by the decrease of the azide peak at 2100 cm−1 (Figure 6b). Representative TEM images recorded at different magnifications of the resulting cross-linked

• system equipped with an auto sampler system, a temperature-controlled pump, a column oven, a refractive index (RI) detector, a purge and degasser unit and a TSKgel superhZ2000, 4.6 mm ID × 15 cm × 2cm column. Tetrahydrofuran was used as an eluent at a flow rate of 1.0 mL/min at 40 °C. The refractive index

• ][42][43]. For the synthesis, 500 mg of red phosphorus, 20 mg of Sn and 10 mg of SnI4 were placed into a quartz ampoule with the dimensions of 20 cm length and 1.5 cm width. The air was evacuated by vacuum, and the ampoule was left to dry at least for 30 min under vacuum. The sealed ampoule was placed

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• methoxy substituent in para-position, gave the highest value of 5770 cm−1. The fluorescence quantum yields of 4a–d were calculated with a comparative method, where quinine sulfate (SQ) in 0.1 M H2SO4 was used as standard [66]. The fluorescence and absorbance spectra for quinine sulfate and product 4b are

• PC spectrophotometer in quartz cuvettes with a path length of 1 cm. Emission spectra were recorded on a Perkin-Elmer LS 50B spectrofluorimeter. Cyclic voltammetry was performed in anhydrous acetonitrile solution containing 0.1 M of tetrabutylammonium tetrafluoroborate (n-Bu4NBF4) as a supporting

Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction

• Ren-Jie Fang,
• Chen Yan,
• Jing Sun,
• Ying Han and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159

• , 125.6, 121.7, 120.7, 120.3, 119.2, 111.3, 21.1; IR (KBr) ν: 2988, 1786, 1734, 1611, 1485, 1456, 1357, 1314, 1185, 1021, 988, 786, 734 cm−1; HRMS–ESI-TOF (m/z): [M + Na]+ calcd for C34H22NaN2O3, 529.1523; found, 529.1512. 2. General procedure for the preparation of carbazoles 6a–n: To a round-bottomed

• , 127.0, 126.9, 126.4, 122.4, 122.0, 121.8, 121.6, 119.6, 108.7, 32.1; IR (KBr) ν: 3057, 3023, 2907, 2360, 2339, 1720, 1605, 1482, 1320, 1267, 1172, 1009, 936, 805, 743, 612, 447 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C39H27NO2, 564.1934; found, 564.1926. The crystallographic data of the compounds 3a

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• −9.5 (c 0.02, MeOH); UV (MeOH) λmax, nm (log ε): 276 (3.23); IR (cm−1) νmax: 3333, 1677 1660, 1538, 1493, 1203, 1138; NMR data, see Table 1; HRESIMS (m/z): [M − 1]− calcd for C11H13N2O4, 237.0880; found, 237.0874, Δ = −2.53 ppm. Pseudomonin B (2): yellowish oil; [α]D25 −13.3 (c 0.05, MeOH); UV (MeOH

• ) λmax, nm (log ε): 297 (3.64); IR (cm−1) νmax: 3137, 1673, 1660; NMR data, see Table 1; HRESIMS (m/z): [M + H]+ calcd for C16H21O4N4, 333.1557; found 333.1561, Δ = 1.20 ppm. Pseudomonin C (3): white amorphous solid; [α]D25 −45.6 (c 0.02, MeOH); UV (MeOH) λmax, nm (log ε): 299 (3.85); IR (cm−1) νmax

• : 3341, 2927, 1670, 1633, 1205; NMR data, see Table 1; HRESIMS (m/z): [M + H]+ calcd for C19H23N2O4, 343.1652; found, 343.1653, Δ = 2.01 ppm. Pseudomobactin A (4): yellow amorphous solid; [α]D25 −17.7 (c 0.05, MeOH); UV (MeOH) λmax, nm (log ε): 260 (3.59), 302 (4.12); IR (cm−1) νmax: 3320, 2930, 1675

Synthesis and antimicrobial activity of 1H-1,2,3-triazole and carboxylate analogues of metronidazole

• Satya Kumar Avula,
• Syed Raza Shah,
• Khdija Al-Hosni,
• Muhammad U. Anwar,
• Rene Csuk,
• Biswanath Das and
• Ahmed Al-Harrasi

Beilstein J. Org. Chem. 2021, 17, 2377–2384, doi:10.3762/bjoc.17.154

• antifungal activity of all compounds were evaluated by inhibiting the growth of Didymella sp. (Figure 7 and Table 3). The fungal colony after 7 days of control treatment was noted to be 8.6 cm in diameter. Whereas, the growth of the fungal colony was detected maximum, i.e., 8.8 ± 0.2 and 9.0 ± 0.3 cm against

• compound 2 and 3, respectively. However, compound 5e and 7c efficiently inhibited the fungal growth by limiting the colony diameter to 3 ± 0.3 and 3.1 ± 0.2 cm followed equally by compound 7b and compound 5b with 4.1 ± 0.3 and 4.6 ± 0.2 cm, respectively. Compared to control and metronidazole treatments

• , room temperature, 4–5 h, 86–93%. Synthesis of 1H-1,2,3-triazole compounds 5a–i. Synthesis of carboxylate compounds 7a–e. Antifungal zone (cm) of metronidazole derivatives 5a–i and 7a–e. Antibacterial activities (OD 600 nm) of metronidazole derivatives 5a–i and 7a–e.a Supporting Information Supporting

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• -tetrahydrodehydrodiconiferyl alcohol 4-O-α-ʟ-rhamnopyranoside and was named aleuritiside C. Compound 15 was obtained as a yellow gum. The [M + Na]+ ion peak at m/z 411.1260 (calcd for 411.1267) in the HRESIMS corresponded to the molecular formula C17H24O10. The IR spectrum exhibited signals at 3321 cm−1 and 1675 cm−1

• semipreparative HPLC (30% aq. CH3CN) to yield compound 9 (10 mg). Aleuritiside A (1). Colorless gum; [α]D25 −12.1 (c 0.05, MeOH); IR (KBr) νmax: 3360, 2943, 2830, 1448, 1033 cm−1; UV (MeOH) λmax, nm (log ε): 282 (1.40), 228 (3.61); ECD (MeOH) λmax, nm (Δε): 292 (5.3), 248 (3.3), 221 (−2.1); 1H and 13C NMR data

• , see Table 1; positive HRMS–FAB (m/z): [M + Na]+ calcd for C25H32O11Na, 531.1837; found, 531.1844. Aleuritiside B (2). Colorless gum; [α]D25 −15.4 (c 0.05, MeOH); IR (KBr) νmax: 3355, 2945, 2832, 1453, 1033 cm−1; UV (MeOH) λmax, nm (log ε): 283 (1.31), 230 (3.53); ECD (MeOH) λmax, nm (Δε): 276 (−3.3

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• obtained from the nucleophilic substitution reaction of intermediate 8 in 85% yield. The 1H and 13C NMR spectra of compounds 8 and 9 were similar, but in the IR spectrum of intermediate 9, it was possible to observe the characteristic stretching of the azide group at 2103 cm−1. The 1,3-dipolar

• products 1a,b, and 2a–j, respectively, with 30–84% yields. This last step was adapted from a method already described in the literature [31]. The formation of compounds 1a,b and 2a–j was observed by the disappearance of the characteristic stretching of the azide groups at 2107 and 2103 cm−1 in the IR

• spectra, which are present in intermediates 5 and 9, respectively, and compounds 2a–j showed carbonyl absorption at 1671–1660 cm−1 (amide). 1H NMR spectrum analysis showed the appearance of a single signal at 8.52 ppm and between 8.61–7.79 ppm referring to the hydrogen of the 1,2,3-triazole (C-5) for

Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• ). Nomimicin B (1) Colorless amorphous solid; [α]D23 −29 (c 0.10, MeOH); UV (MeOH) λmax (log ε) 246 (3.83), 293 nm (3.71); ECD (c 9.5 × 10−5, MeOH) λext (Δε) 208 (−5.27), 247 (+3.72), 294 nm (−1.24); IR νmax: 3360, 2965, 1755, 1619, 1408, 1088, 998 cm−1; see Table 1 for 1H and 13C NMR data; HRESITOFMS (m/z

• , 1007 cm−1; see Table 1 for 1H and 13C NMR data; HRESITOFMS (m/z): [M + Na]+ calcd for C30H40O7Na, 535.2666; found, 535.2665. Nomimicin D (3) Colorless amorphous solid; [α]D23 −70 (c 0.10. MeOH); UV (MeOH) λmax (log ε) 243 (3.99), 302 nm (3.54); IR νmax: 3380, 2963, 1723, 1619, 1413, 1258, 1010 cm−1

• (Δε) 208 (−4.98), 244 (+3.85), 298 nm (−1.09); IR νmax: 3348, 2938, 1735, 1620, 1435, 997 cm−1; HRESITOFMS (m/z): [M + Na]+ calcd for C30H40O6Na, 519.2717; found, 519.2722. ECD calculations The conformational sampling of structure 4a was performed by applying 100,000 steps of the Monte Carlo Multiple

Facile and innovative catalytic protocol for intramolecular Friedel–Crafts cyclization of Morita–Baylis–Hillman adducts: Synergistic combination of chiral (salen)chromium(III)/BF₃·OEt₂ catalysis

• Karthikeyan Soundararajan,
• Helen Ratna Monica Jeyarajan,
• Raju Subimol Kamarajapurathu and
• Karthik Krishna Kumar Ayyanoth

Beilstein J. Org. Chem. 2021, 17, 2186–2193, doi:10.3762/bjoc.17.140

• filtration, the solvent was removed under reduced pressure and the crude product was purified on silica gel (using hexane/EtOAc) to afford the desired product 6a as a white solid (81%). Methyl 1H-indene-2-carboxylate (6a): Yield: 160 mg (81%); white solid; mp 85–87 °C; IR (cm−1): 3062, 2953, 2884, 1947, 1735

• mg (67%); off-white solid; mp 194–196 °C; IR (cm−1): 1674, 1652, 1582, 1568, 1454, 1278, 1117; 1H NMR (CDCl3, 400 MHz) δH 8.31–7.46 (m, 5H, Aro-H), 7.14 (s, 1H, N=CH), 4.56–4.50 (t, J = 8 Hz, 2H, CO-CH2), 2.84–2.79 (t, J = 8 Hz, 2H, N-CH2); 13C NMR (CDCl3, 100 MHz) δC 185.12 (1C, C=O), 133.02–128.83

• purified by column chromatography to afford the corresponding [3 + 2] cycloaddition product 8a in 61% yield. Compound (8a): Yield: 192 mg (61%); yellowish oil; IR (cm−1): 2972, 2254, 1954, 1562, 1671, 1455, 1245; 1H NMR (CDCl3, 400 MHz) δH 7.80–7.06 (m, 9H, Aro-H), 5.90 (s, 1H, HC-N-CO), 4.36–4.21 (m, 2H