Radical cation Diels–Alder reactions of arylidene cycloalkanes

• Kaii Nakayama,
• Hidehiro Kamiya and
• Yohei Okada

Beilstein J. Org. Chem. 2022, 18, 1100–1106, doi:10.3762/bjoc.18.112

• ). Then, the solution was diluted with water and extracted with EtOAc. The combined organic layers were dried over Na2SO4, filtered, and concentrated in vacuo. Yields were determined by 1H NMR analysis using dibromomethane as an internal standard. Silica gel column chromatography (hexane/ethyl acetate

• analysis using dibromomethane as an internal standard. Silica gel column chromatography (hexane/ethyl acetate) gave the corresponding spiro ring compound. Plausible mechanism of the radical cation Diels–Alder reaction (EDG: electron-donating group). Landscape of the radical cation Diels–Alder reaction

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

• -phenyl derivatives and a series of six novel N-thiazolyl derivatives was obtained in 10–70% and 12–35% yield, respectively, after stirring the o-chlorinated arylhydrazones, CuI, KOH, and 1,10-phenantroline for 12–48 hours in DMF at 120 °C. The products were isolated by column chromatography on silica gel

• resealable screw-cap Schlenk flask (≈10 mL volume) in the presence of a Teflon-coated magnetic stirring bar. TLC analyses were performed with Al plates covered with silica gel (SiliCycle, F254) and visualized by UV detection. Silica gel (Vetec, 0.063–0.200 mm, 70–230 mesh) was used for column chromatography

• %), CuI (0.019 g, 20 mol %), and DMF (2.5 mL) were successively added under N2 atmosphere. The reaction mixture was stirred and heated at 120 °C for 12–48 h (see Table 1). After cooling to room temperature, AcOEt (10 mL) was added to the mixture. This was passed through a short column with silica gel 60

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• , and then, the solution was extracted with dichloromethane. The dichloromethane extract was dried over anhydrous MgSO4, filtrated, and concentrated. The residue was chromatographed on silica gel (ethyl acetate/hexane 1:4 ) to give OTK-2 (19 mg, yield 27%) and OTT-2 (9 mg, yield 14%) as a light yellow

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• Streptomyces sp. RM72 were first partitioned by water and ethyl acetate, and then the organic layer was further fractionated by silica gel column chromatography. Fractionation by reversed-phase HPLC yielded ten compounds (1–10) that generate N2H4 upon acid hydrolysis. The combination of 1H and 13C NMR with a

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• spectrometer with TMS as an internal standard. HRMS–ESI data were obtained through an Agilent 1290 UPLC/6540 Q-TOF mass instrument. Column chromatography (CC) was performed using silica gel (30–400 mesh, Qingdao Marine Chemical Inc., China), Sephadex LH-20 (25–100 µm, Pharmacia Biotech Ltd., Sweden), and MCI

• gel (75–150 µm, Mitsubishi Chemical Corporation, Tokyo, Japan). Semipreparative HPLC was conducted on a HITACHI Chromaster system equipped with a DAD detector, a YMC-Triart C18 column (250 × 10 mm, i.d. 5 μm), and a flow rate of 3.0 mL/min. LC–MS was performed using an Agilent 1200 series HPLC system

• , the extract was purified by silica gel chromatography and semipreparative HPLC to yield daturamycin A (1) (4.5 mg), daturamycin B (2) (1.8 mg), daturamycin C (3) (8.7 mg), terferol (4) (2.4 mg), BTH-II0204-207: D (5) (2.1 mg), betulinan A (6) (6.2 mg). Identification of new compounds Daturamycin A (1

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

• selected as the LAG agent keeping all other parameters the same. Interestingly, the monobrominated product 2a was obtained almost exclusively in an excellent yield (91%) within just 5 min of grinding (Table 1, entry 6). The attempted model reaction under solid-state grinding using silica gel was sluggish

• Agate mortar–pestle. In each case, once the reaction got over, the crude product was directly slurried by the addition of silica gel (230–400 mesh, approximately 1 g) and purified by flash chromatography eluting with varying proportions of EtOAc/petroleum ether; thus, a typical work-up step was avoided

• conversion was observed, 0.8–1 g of silica gel (230–400 mesh) was added and the slurry was subjected to flash chromatography and eluted with a mixture of EtOAc/petroleum ether to afford the pure monobromo phenol derivative. The side product succinimide was subsequently eluted using MeOH/CHCl3 1:10

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• was added to the catholyte and the mixture was left under ultrasound irradiation for 30 minutes. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel. The first experiment (Table 1, entry 1) was carried out using stainless steel as cathode

• Sigma-Aldrich and Alfa Aesar and used as received. All air/moisture sensitive reactions were carried out under an inert atmosphere, in oven-dried or flame-dried glassware. TLC was performed on aluminium plates precoated with silica gel 60 with an F254 indicator; visualized under UV light (254 nm) and/or

• by staining with potassium permanganate. Flash column chromatography was performed using high purity silica gel, pore size 60 Å, 230–400 mesh particle size, purchased from Merck. 1H NMR and 13C NMR spectra were recorded in CDCl3 (purchased from Cambridge Isotope Laboratories) at 298 K using a Bruker

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• Shimadzu IRAffinity-1 infrared spectrometer. HRMS were measured on a Thermo Scientic Exactive FTMS spectrometer. Melting points were uncorrected. Column chromatography was performed on silica gel 60. THF was distilled from sodium benzophenone ketyl radical. TMSCl, TEA, and DMF were distilled from CaH2

• by column chromatography on silica gel (hexanes/EtOAc) to give 146 mg of 7a [23] (78% yield) as a mixture of two diastereomers (78:22 dr). A solution of 7a (146 mg) and PPTS (10 mg) in toluene (10 mL) was refluxed using the Dean–Stark apparatus under nitrogen atmosphere for 1 h. After removal of the

• solvent in vacuo, the residue was purified by column chromatography on silica gel (hexanes/EtOAc) to give 95 mg of 3a [8][23] (56% yield in two steps). Electroreductive coupling of phthalic anhydrides with α,β-unsaturated carbonyl compounds and subsequent treatment with 1 M HCl (previous work

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

• previously reported [13], the separation (by any mean) of the 2-hydroxypyrazine isomers 3 and 4 is challenging. To overcome this, we used water-heated columns and preheated eluent mixtures (see the experimental part) which allowed to run chromatography over silica gel at 60 °C. At this temperature and using

• tetraalkylammonium hydroxides as bases does improve the reaction yield, especially when starting from phenylalanine amide (2{2}). Moreover, the recourse to chromatography over silica gel at 60 °C was a crucial experimental setting to properly separate and characterize the two isomers occurring. Mechanism-wise the

• , respectively. Shifts (δ) are given in ppm with respect to the TMS signal and cross-coupling constants (J) are given in hertz. Column chromatography was performed either on Merck silica gel 60 (0.035–0.070 mm) or neutral alumina containing 1.5% of added water using a solvent pump and an automated collecting

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• solvent signals, and coupling constants (J) were in Hz. HRESIMS spectra were recorded on an Agilent G6520 Q-TOF mass spectrometer, while HREIMS spectra were recorded on a Finnigan-MAT-95 mass spectrometer (Thermo Fisher Scientific, Waltham, USA). Commercial silica gel (Qingdao Haiyang Chemical Group Co

• ., Ltd., Qingdao, China, 200–300 and 300–400 mesh), Sephadex LH-20 gel (Amersham Biosciences), and MCI gel (CHP 20P, 75–150 μm, Mitsubishi Chemical Co., Ltd., Tokyo, Japan) were used for column chromatography (CC). Reversed-phase (RP) HPLC was performed on an Agilent 1260 series liquid chromatography

• (80.1 mg) was purified by RP-HPLC (65% MeOH in H2O, 3.0 mL/min) to give 4 (2.7 mg, tR = 16.2 min). The subfraction C2 (66.5 mg) was successively separated by silica gel CC (PE/Et2O 5:1 to 1:1) and RP-HPLC (75% MeCN in H2O, 3.0 mL/min) to give 3 (3.6 mg, tR = 9.8 min). The subfraction E (34.9 mg) was

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

• Melting points were determined in open capillaries with a digital melting point IA9100series apparatus (ThermoFisher Scientific). All reactions and purity of the synthesized compounds were monitored by TLC using silica gel 60 F254 aluminum plates (Merck). Visualization was accomplished by UV light. Column

• chromatography was performed using silica gel 60 (0.040–0.063 mm) (Merck). NMR spectra were recorded on a Bruker Ascend 400 spectrometer (400 MHz and 100 MHz for 1H and 13C, respectively). 1H NMR and 13C NMR were referenced to residual solvent peaks. High-resolution mass spectrometry (HRMS) analyses were carried

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• ]. Column chromatography was carried out on silica gel (300–400 mesh). Analytical thin-layer chromatography was performed on glass plates of silica gel GF-254 with detection by UV. Standard techniques for synthesis under inert atmosphere and Schlenk glassware equipped with an 8 mm PTFE vacuum stopcock, were

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• methanol (1.0 L), dried under vacuum, and the resultant MeOH extract was then extracted with hexane (120 mL) and dried again under vacuum. The hexane extract was purified by flash chromatography (Biotage Isolera Prime) over a silica gel column (eluent: cyclohexane/EtOAc 100:0 to 80:20 to 0:100). The

Direct C–H amination reactions of arenes with N-hydroxyphthalimides catalyzed by cuprous bromide

• Dongming Zhang,
• Bin Lv,
• Pan Gao,
• Xiaodong Jia and
• Yu Yuan

Beilstein J. Org. Chem. 2022, 18, 647–652, doi:10.3762/bjoc.18.65

• -layer chromatography (TLC) on gel F254 plates. Flash column chromatograph was carried out using 300–400 mesh silica gel at medium pressure. General procedure for synthesis of 3a–u: N-Hydroxyphthalimide (0.1 mmol), CuBr (40 mol %, 0.04 mmol), triethyl phosphite (6.0 equiv, 0.6 mmol) and (hetero)arene (2

• gel (ethyl acetate/petroleum ether 1:10) to afford the desired products 3a–u. Amination of arenes with phthalimides. Substrate scope of the copper-catalyzed C–H imidation of arenes. Reaction conditions: 1 (2.0 mL as substrate and solvent), 2a (0.10 mmol), CuBr (0.04 mmol) and P(OEt)3 (0.6 mmol) were

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• was performed using a Gilson 321 pump with a Shodex Refractive Index Detector, an INNO column C18 5 μm column (250 × 10 mm), and a Lux 5 μm Cellulose-1 column (250 × 4.6 mm). Silica gel 60 (Merck, 70–230 mesh and 230–400 mesh), RP-C18 silica gel (Merck, 230–400 mesh), Sephadex LH-20 (Parmacia Co

• ., Japan), and Diaion HP-20 (Mitsubishi Chemical Co., Japan) were used for column chromatography. Merck precoated silica gel F254 plates and reversed-phase (RP)-18 F254s plates (Merck) were used for thin-layer chromatography (TLC). Spots of compounds on TLC were detected under UV light or by heating after

• to a silica gel column (CHCl3/MeOH, 20:1 → 1:1) to give five fractions (C1–C5). Fraction C2 (3.0 g) was applied to an RP-C18 silica gel column (50% MeOH) to give 12 subfractions (C2a–C2l). Compound 6 (4 mg, tR = 25.9 min) was yielded by purifying subfraction C2h (32 mg) using a semipreparative HPLC

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

• were not corrected. Thin-layer chromatography was performed using TLC aluminum sheets with silica gel (Merck 60 F254). Visualization was accomplished by UV light. Column chromatography was performed using silica gel 60 (0.040–0.063 mm, Merck). NMR spectra were recorded on a Bruker Ascend 400 (400 MHz

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• -2000 polarimeter. ESI-TOF mass spectra were obtained using a TOF/Q-TOF Mass spectrometer. Thin-layer chromatography (TLC) and preparative TLC were performed on silica gel 60 GF254 (Merck). Column chromatography (CC) was conducted on silica gel (Merck) type 100 (70–230 mesh ASTM) and type 60 (230–400

• mesh ASTM), Sephadex LH-20, or reversed-phase C18 silica gel. Fungal material The fungus PSU-SPSF346 was isolated from a soil sample collected from the Sirindhorn Peat Swamp Forest, Narathiwat Province, Thailand. This fungus was deposited as BCC88125 at BIOTEC Culture Collection (BCC), National Center

• ). Subfraction A4F6 (770.3 mg) was separated by CC over silica gel using a mixture of EtOAc/CH2Cl2/MeOH 18:1:1 to give 12 subfractions (A4F6A–A4F6L). Subfraction A4F6H contained compound 3 (91.3 mg). Subfraction A4F6J (532.4 mg) afforded compound 4 (178.3 mg) after purification by CC over reversed-phase C18

Tosylhydrazine-promoted self-conjugate reduction–Michael/aldol reaction of 3-phenacylideneoxindoles towards dispirocyclopentanebisoxindole derivatives

• Sayan Pramanik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 469–478, doi:10.3762/bjoc.18.49

• reaction was checked by TLC glass sheets pre-coated with silica gel (with binder, 300 mesh, Spectrochem) and column chromatography was performed using silica gel (100–200 mesh). Bruker 300 MHz and 400 MHz instruments were used for 1H and 13C NMR spectra at 300 MHz, 400 MHz and 75 MHz, 100 MHz respectively

• EtOAc (3 × 10 mL). The organic layers were combined and washed with brine, then dried over anhydrous Na2SO4. After the solvent was removed under reduced pressure, the crude product was purified by column chromatography using 100–200 mesh silica gel and petroleum ether–ethyl acetate mixture as the eluent

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

• chromatography was performed on silica gel 60 (230–400 mesh, particle size 0.040–0.063 mm, Merck). Bromopropargylic alcohols 1a–c and chloropropargylic alcohol were prepared according to published methods [22][23][59]. Phenol (2a), naphthalen-1-ol (2b), naphthalen-2-ol (2c), 4-nitrophenol (2d), 2-nitrophenol (2e

• mixture was stirred at 50–55 °C for 3 h, filtered and concentrated. The residue was purified by flash column chromatography on silica gel (5.0 × 4.0 cm, gradient elution, C6H14/Et2O, 2:1 followed by Et2O, Me2CO) to give products 3a (10 mg, 4%), 4a (214 mg, 55%), 5a (30 mg, 22%) and 7 (11 mg, 5%). Scope of

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• J-815 CD spectropolarimeter. Optical rotations were measured with a Jasco P-1020 polarimeter. Semi-preparative HPLC (Agilent Technologies 1260 Infinity II) equipped with a reversed-phase column ((YMC-packed C18, 5 µm, 250 × 10 mm, 2.0 mL/min) was used to purify samples. Silica gel (300–400 mesh

• , Qingdao) was used for column chromatography (CC), and precoated silica gel plates (GF254, Qingdao) were used for TLC. Soft coral material The soft coral Lobophytum pauciflorum was collected from Yongle Islands of Xisha Islands of the South China Sea in May 2012. The sample was identified by Pingjyun Sung

• subjected to silica gel column chromatography (CC) eluted with two gradient systems, PE/acetone (1:0 to 1:1) and subsequently CH2Cl2/MeOH (15:1 to 1:1) to afford 8 fractions. Fraction 4 (14.6 g) was split (chromatographed on) by silica gel eluting with a gradient of PE/acetone (30:1 to 1:1) to give three

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• supernatant by filtration, the adsorbed compounds were eluted from the resin with methanol. The resulting extract was concentrated to dryness and a first preliminary fractionation was accomplished by flash column chromatography on reversed-phase silica gel using increasing concentrations of methanol in water

Organocatalytic asymmetric nitroso aldol reaction of α-substituted malonamates

• Ekta Gupta,
• Narendra Kumar Vaishanv,
• Sandeep Kumar,
• Raja Krishnan Purshottam,
• Ruchir Kant and
• Kishor Mohanan

Beilstein J. Org. Chem. 2022, 18, 217–224, doi:10.3762/bjoc.18.25

• (100–200 mesh silica gel) using EtOAc/hexane as the eluent to afford product 4a as white solid (71 mg, 90%). Rf 0.20 (EtOAc/hexane 3:7); mp 115–117 °C; 1H NMR (400 MHz, CDCl3) δ 9.04 (s, 1H), 7.47–7.44 (m, 5H), 7.31–7.26 (m, 2H), 7.20–7.14 (m, 3H), 3.81 (s, 3H), 1.59 (s, 3H) ppm; 13C NMR (100 MHz

• silica gel column chromatography. Enantioselectivities were determined by chiral HPLC analysis. Variation of ester moiety of malonamates and nitrosoarenes. General conditions: 1 (0.20 mmol), 2a (0.24 mmol), 3a (0.04 mmol), toluene (3.0 mL). Yields refer to isolated yields after silica gel column

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• (P3657) and DANA (D9050) were purchase from Sigma-Aldrich. Neuraminidase from Clostridium perfringens (C. Welchii) was purchased from Sigma-Aldrich (N2876-6U) and Milli-Q water was used to prepare all buffers. Thin-layer chromatography (TLC) was performed on pre-coated silica gel 60 F254 plates (Merck

• (GE Healthcare). The column was washed with buffer A to remove unbound proteins followed by elution of bound proteins with buffer B (50 mM Tris-HCl, pH 8.0, 150 mM NaCl, 500 mM imidazole). Further purification was carried out by gel filtration chromatography (Superdex S200 16/600 column, GE Healthcare

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

• performed using silica gel (200–300 mesh and H, Qingdao Marine Chemical Co. Ltd., Qingdao, People's Republic of China), RP-18 gel (40–63 μm, Merck, Darmstadt, Germany), and MCI gel (75–150 μm; Mitsubishi Chemical Corporation, Japan). Fractions were monitored by TLC (GF254, Qingdao Marine Chemical Co. Ltd

• ., Qingdao), and spots were visualized by heating silica gel plates sprayed with 10% H2SO4 in EtOH. All solvents were distilled prior to use. Plant materials The dried stems and roots of W. nutans were collected in Xinzhou City of Guangxi Province, People’s Republic of China, in August 2019, and

• and EtOAc. The EtOAc extract (EE) fraction (110 g) was chromatographed over a silica gel (100–200 mesh) column (20 × 100 cm), eluted with dichloromethane/methanol (50:1 to 0:1 v/v) to afford 10 fractions (EE1-EE10). The fraction EE4 (13.3 g) was further purified by semi-preparative HPLC [phenyl column

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

• ). To mitigate this, the milling experiment was repeated using silica gel (SiO2) as a milling auxiliary. The use of SiO2 did not affect significantly the product composition of the reaction as determined by NMR analysis of an independent experiment milling 1c and NFSI (2.0 equiv) at 30 Hz for 3 h. This