Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Valerii V. Tkachev,
• Andrey N. Utenyshev,
• Olga Yu. Karlutova,
• Alexander D. Dubonosov,
• Vladimir A. Bren,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2020, 16, 1820–1829, doi:10.3762/bjoc.16.149

• heterocyclic aldehydes or ketones with methylene succinates followed by subsequent hydrolysis and dehydration processes. Under exposure of solutions or crystals of thus prepared hetaryl(aryl)-substituted dihydrofuran-2,5-diones to UV light, those bearing an isopropylidene fragment attached to the furandione

• : The X-ray diffraction studies of crystals of 3Z, 3E and 9 were performed with a Bruker XSCANS device (λ(Мо Кα) = 0.71073 Å, \w scans). Bond lengths and valence angles of 3Z, 3E and 9 are presented in Tables S1–S3 (Supporting Information File 1). The main crystallographic data and characteristics are

Microwave-assisted efficient one-pot synthesis of N²-(tetrazol-5-yl)-6-aryl/heteroaryl-5,6-dihydro-1,3,5-triazine-2,4-diamines

• Moustafa Sherief Moustafa,
• Ramadan Ahmed Mekheimer,
• Saleh Mohammed Al-Mousawi,
• Mohamed Abd-Elmonem,
• Hesham El-Zorba,
• Afaf Mohamed Abdel Hameed,
• Tahany Mahmoud Mohamed and
• Kamal Usef Sadek

Beilstein J. Org. Chem. 2020, 16, 1706–1712, doi:10.3762/bjoc.16.142

• Labstation at 120 °C for 12 min. The solvent was removed under reduced pressure and the solid product was isolated by filtration and recrystallized from DMF. 6-(4-Chlorophenyl)-N2-(5H-tetrazol-5-yl)-5,6-dihydro-1,3,5-triazine-2,4-diamine (4a). Colorless crystals; mp 320–322 °C; yield 0.268 g, 92%; Rf 0.55 (1

• . calcd for C10H10ClN9: C, 41.17; H, 3.46; Cl, 12.15; N, 43.22; found: C, 41.22; H, 3.42; Cl, 12.11; N, 43.24; EIMS (m/z): 290.1 [M − 1]+. 6-(4-Methoxyphenyl)-N2-(5H-tetrazol-5-yl)-5,6-dihydro-1,3,5-triazine-2,4-diamine (4b). Colorless crystals; mp 306–308 °C; yield 0.255 g, 89%; 1H NMR (600 MHz, DMSO-d6

• ; N, 43.88; found: C, 45.89; H, 4.52; N, 43.90; EIMS (m/z): 286.1 [M − 1]+. 6-Phenyl-N2-(5H-tetrazol-5-yl)-5,6-dihydro-1,3,5-triazine-2,4-diamine (4c). Colorless crystals; mp 317–319 °C; yield 0.277 g, 93%; 1H NMR (600 MHz, DMSO-d6) δ 6.15 (s, 1H), 7.22 (s, 1H), 7.40–7.46 (m, 5H), 8.50 (br s, 1H

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• crystals from derivative 8a were unsuccessful. It has to be emphasized that theoretically, the formation of four dimer-like regioisomers could be expected from aldehydes 1a–d, each of them as the mixture of two diastereomeric racemates. Although HPLC–MS measurements indeed indicated the presence of

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• layer was washed with brine and dried over anhydrous MgSO4. The removal of the solvent in vacuo afforded the crude product, which was purified over silica gel (using hexane/EtOAc) to acquire 4a as colorless crystals. Proposed mechanism for the synthesis of 1,4-disubstituted triazoles. Proposed mechanism

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

• structure of rotaxane 1a was determined by single crystal X-ray diffraction of crystals obtained by slow evaporation of a dichloromethane solution. The analysis of the X-ray solid-state structure of the rotaxane 1a showed a significant difference to Leigh’s rotaxane I [4]. Rotaxane I only presented two

• ; found, 501.20295. Crystal structure determination Single crystals of rotaxane 1a (C36H42FeN3O3) were obtained by slow evaporation of a dichloromethane solution. A suitable crystal was mounted on a cryoloop with paratone®-N oil on an AFC11 partial Chi goniometer. The data were collected at 120 K on

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• observed that crystals of santonine would shatter when exposed to sunlight [28]. Credit for the pioneering of photochemistry is usually given to Ciamician, the “grandfather of photochemistry”, who reported many interesting transformations of chemical solutions when irradiated by sunlight [29][30]. His

One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• –0.200 mm). High-resolution mass spectra (HRMS) were acquired on a Thermo Scientific, model Q-Exactive high resolution LC–MS/MS with a resolution of up to 150000FWHM at m/z 200. X-ray structure determination: Colorless single crystals of compounds 25 and 26 were obtained from DMSO/H2O. Diffraction data

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• photochemical [2 + 2] cycloaddition reaction was performed both in benzene solution and in the solid state, affording 78% yield with a ratio of syn/trans 8.7:1 and 61% de for syn-isomers at 15 °C in crystals, while no diastereoselectivity could be observed in benzene solution [16] (Scheme 72). In 2001, they

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• '-Hydroxy-5'-oxo-1',2',5',9b'-tetrahydrospiro[cyclohexane-1,3'-pyrrolo[2,1-a]isoindole]-1'-carbonitrile (7): 2 mg (2%), oily crystals; 1H NMR (CD3OD, 600 MHz) δ 7.81 (dd, J = 1.0, 7.6 Hz, 1H), 7.70 (dt, J = 1.3, 7.6 Hz, 1H), 7.65 (dt, J = 1.3, 7.6 Hz, 1H), 7.48 (dd, J = 1.0, 7.6 Hz, 1H), 4.55 (br s, 3H

• ), 3.48–3.42 (m, 1H), 2.65–2.59 (m, 1H), 2.06–2.00 (m, 2H), 1.86–1.78 (m, 2H), 1.53–1.27 (m, 7H); MS m/z (% relative intensity): 282 (100), 283 (18.4), 284 (1.6). 1,3,4,4a,5,11a-Hexahydro-6H-dibenzo[b,e]azepine-6,11(2H)-dione (8): 4 mg (4%), oily crystals; 1H NMR (CD3OD, 300 MHz) δ 7.83–7.77 (m, 1H), 7.71

• , 1C), 30.1 (t, 1C), 26.2 (t, 1C), 23.7 (t, 1C), 21.3 (t, 1C); MS m/z (% relative intensity): 229 (100), 230 (15.1), 231 (1.1). 1,6-Dioxo-1,4,5,6-tetrahydro-2H-spiro[benzo[c]azocine-3,1'-cyclohexane]-5-carbonitrile (9): 3 mg (3%), oily crystals; 1H NMR (CD3OD, 300 MHz) δ 8.19-8.15 (m, 1H), 8.04–8.00 (m

Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes

• Grzegorz Mlostoń,
• Mateusz Kowalczyk,
• André U. Augustin,
• Peter G. Jones and
• Daniel B. Werz

Beilstein J. Org. Chem. 2020, 16, 1288–1295, doi:10.3762/bjoc.16.109

• the slightly more polar one was isolated and identified as the minor isomer of 9d. In the course of crystallization from hexane the less polar fraction gave single crystals suitable for the X-ray diffraction analysis, which unambiguously confirmed that in this molecule the Ph(C-5) and Fc(C-2) groups

• -dicarboxylate (cis-9a): Yield: 159 mg (98%); red crystals; mp 192–193°C; 1H NMR δ 2.65 (dd, JH,H = 13.9 Hz, JH,H = 4.3 Hz, 1H, HC(4)), 3.44 (s, 3H, OCH3), 3.46 (s, 3H, OCH3), 3.56 (dd, JH,H = 13.9 Hz, JH,H = 12.7 Hz, 1H, HC(4)), 3.51–3.60 (m, 1H, HC(Fc)), 4.00–4.02 (m, 1HC(Fc)), 4.07 (s, 5HC(Fc)), 4.27–4.29 (m

• , 5.22; S, 5.93; found: C, 66.58; H, 5.24; S, 5.99. Dimethyl 2,2-diferrocenyl-5-phenyl tetrahydrothiophene-3,3-dicarboxylate (9b): Yield: 54 mg (28%); red crystals; mp 170 °C (dec.); 1H NMR δ 2.91 (dd, JH,H = 14.0 Hz, JH,H = 6.2 Hz, 1H, HC(4)), 3.36 (s, 3H, OCH3), 3.41 (dd, JH,H = 15.8 Hz, JH,H = 12.4 Hz

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• . After completion of the reaction, water was added to the mixture until precipitation appeared. The precipitate was collected by filtration and washed with plenty of water to remove excess CuCl2, NH4OAc, and reduced copper salt. Compound Q1 (1.4 g, 78%) was obtained as yellowish crystals. 1H NMR (400 MHz

• ): Quinazoline derivative (Q1, 0.25 g, 0.79 mmol), 3,6-di-tert-butylcarbazole (0.48 g, 1.7 mmol) and sodium hydride (0.50 g, 1.6 mmol) in dry dimethylformamide (DMF) were used for the nucleophilic substitution reaction. The title compound was obtained as yellowish crystals in a yield of 0.25 g, 37%; Tm = 181 °C

• mmol) and sodium hydride (0.50 g, 1.6 mmol) in dry dimethylformamide (DMF) were used for the nucleophilic substitution reaction. The title compound was obtained as yellowish crystals in a yield of 0.10 g, 21%; Tm = 233 °C; 1H NMR (400 MHz, CDCl3) δ 8.93 (s, 2H), 8.11 (s, 2H), 7.89-7.84 (s, 4H), 7.56 (s

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• immediately after vacuum drying suggested that some structural parameters, such as the water content, varied in the two analyses. The final proof that the phase change was due to some water molecules escaping the crystal, and this proof came from the X-ray diffraction analysis of heated crystals of F-1 (with

• of 15–30 μm. SEM imaging of crystals of F-1 in the F-1a phase formed from a DMSO/water system indicated the existence of two types of crystals (Figure 4). Type 1 was a set of platelets with heights of 0.7–1 mm, grown from a common planar base with a diameter of 0.1–0.3 mm. In other words, the

• crystals were a typical druse setup. Type 2 were well-formed, nonisotropic crystals with two parallel planes in varying sizes (0.3 × 0.4 × 1 mm). The thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) of F-1 was conducted to examine its thermal properties. The TGA curve of the bulk

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• universal attenuated total reflectance (UATR) accessory made of thallium bromide-iodide crystals (KRS-5). The 1H, 13C{1H} and 19F NMR spectra were recorded on Bruker Avance-300 and -400 spectrometers (δ in ppm; J in Hz). All spectra were recorded at room temperature in solution, using CDCl3 as deuterated

• emitting diodes (LEDs) were purchased from Topbright. X-ray crystallography Single crystals of 2c and 4a of suitable quality for X-ray diffraction measurements were grown by slow diffusion of n-pentane into CH2Cl2 solutions of the crude product at –18 °C for several weeks. One selected single crystal was

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

• Nuray Altinolcek,
• Ahmet Battal,
• Mustafa Tavasli,
• William J. Peveler,
• Holly A. Yu and
• Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

• . Carbazole (1) was first brominated with N-bromosuccinimide in dimethylformamide [32][33]. This gave a mixture of mono- and dibromo products 2 and 3. Upon crystallisation 3-bromocarbazole (2) was obtained as white crystals in good yield. 3-Bromocarbazole (2) was then alkylated with 1-bromohexane in 50

• reduced pressure the crude product was obtained as a brown solid. After crystallisation of the crude product with chloroform, the pure product 2 (692 mg, 47%) was obtained as white crystals. Rf (ethyl acetate/hexane, 1:6 v/v): 0.43; melting point: 200–201°C; 1H NMR (600 MHz, CDCI3) δ (ppm) 8.19 (d, J

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• transition (Tg) was noticed at 86 °C, followed by an exothermic crystallization (Tcr) signal observed at 183 °C to obtain crystals, which melted at 201 °C. The crystalline sample of derivative 3 demonstrated a similar behavior. It melted upon the first heating at 174 °C and exhibited a glass transition at Tg

• (250 mL) with vigorous stirring. After filtration and crystallization from methanol compound 2 was obtained as white crystals. Yield (0.60 g, 80%); mp 83–84 °C; 1H NMR (400 MHz, CDCl3) δ 7.46 (d, J = 2.3 Hz, 2H), 7.30 (dd, J = 8.7, 2.3 Hz, 2H), 6.84 (d, J = 8.7 Hz, 2H), 3.98 (q, J = 7.0 Hz, 2H), 1.48

• and the product extracted with dichloromethane. The obtained crude product was purified by column chromatography using ethyl acetate/n-hexane 1:20 as the eluent, recrystallized from the mixture of eluent to afford the target compound 3 as white crystals (0.15 g, 50%). Mp 170–171 °C; 1H NMR (400 MHz

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• annulation was favorable for the formation of six-membered rings. Nevertheless, the existence of several rotamers of 1 derived from the restricted rotation of the peripheral phenyl ring substituents and its nonplanar geometry prevented the structure elucidation by proton NMR analysis [35]. Single crystals of

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• material was purified via column chromatography using silica gel. The BODIPY dimer 7 was prepared using 6 [38] and was obtained as a fluorescent orange solution or as pink-orange crystals in a 30% yield. Similarly, the Pd-catalyzed Sonogashira cross-coupling reaction [39] was successful for the reaction

• extend this family of triptycene-linked porphyrins from dimers to trimers. Single crystal X-ray analyses To further confirm the structures of the substituted triptycene, we obtained single crystals suitable for analysis of the disubstituted triptycenes 5 and 16. The structure of 5 was solved with one

• the porphyrin rings are both possible. However, due to the sever 74.1(7)° rotation between the two 24-atom mean planes of the porphyrin macrocycles and the space occupied by the triptycene, creating a hetero π-stacking would form larger voids in the crystals structure. This would be less favored than

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• ]. Crystallization of derivative 14c from D2O brought the expected results. The analysis confirmed the structure of the resulting compound 14c. The absolute configuration of 14c is consistent with the stereochemistry we proposed based on NMR studies. The crystals of 14c contained the (1R,2S)-diastereoisomer (Figure

• the calculated positions and refined as ‘riding model’ with the isotropic displacement parameters set at 1.2 (1.5 for methyl and hydroxy groups) times the Ueq value for appropriate non-hydrogen atom. As the crystals were obtained from D2O solution, this solvent was used for final model (although, no

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents

• Yumi Yakiyama,
• Shota Hishikawa and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2020, 16, 681–690, doi:10.3762/bjoc.16.66

• the external aromatic ring of the indenopyrene using various types of o-bromo arylaldehydes. Related to our study on buckybowl-containing liquid crystals [19], we planned to introduce alkoxy groups on the 1 framework. Here, we report the synthesis and characterization of dimethoxy derivative 5a and

• dependent on the temperature as shown in Table 1. It is assumed that the ring-rotation process, which generated the regioisomer did not occurred in case of 4a because of two larger methoxy groups than the methylenedioxy group. Crystal structures of 5a–c Single crystals of 5a–c were successfully obtained by

• crystals [19]. Experimental General All experiments with moisture- and air-sensitive compounds were performed in anhydrous solvents under nitrogen atmosphere in flame-dried glassware. All reagents were purchased from commercial sources and used without further purification unless otherwise noted. The

Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes

• Zeguo Fang,
• Nawaf Al-Maharik,
• Peer Kirsch,
• Matthias Bremer,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65

• University, Nablus, Palestine Merck KGaA, Liquid Crystal R&D Chemistry, Frankfurter Str. 250, 64293 Darmstadt, Germany 10.3762/bjoc.16.65 Abstract This paper describes the synthesis of a series of organic liquid crystals (LCs) containing selectively fluorinated cyclopropanes at their termini. The syntheses

• negative dielectric anisotropy. The study gives some guidance into effective structure–property relationships for the design of LCs containing selectively fluorinated cyclopropane motifs. Keywords: dielectric anisotropy; difluorocarbene; organic liquid crystals; selectively fluorinated cyclopropanes

• the requirements for different LCD technologies. For the traditional twisted nematic (TN) LCD technology, devices require liquid crystals with display positive dielectric anisotropy by which the molecular dipole moment is oriented parallel to the long axis of the molecule, while for the current

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• singlet peaks at 8.58, 8.37 and 8.23 ppm due to aromatic protons. The structure of TB4 was unambiguously revealed by single crystal X-ray diffraction analysis (Figure 2). The crystals suitable for X-ray diffraction were obtained by vapor diffusion of hexane into a solution of TB4 in CH2Cl2. The terrylene

• crystals, resulting in the 1D columnar structure as a whole, which is expected to have higher carrier mobility. Recently, oligo-perinaphthalenes, namely oligorylenes, are of great interest as good model compounds of armchair graphene nanoribbons (AGNRs), since AGNRs with a width of N = 3p + 2 are predicted

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• subjected to X-ray crystallographic analysis. Orange single crystals were formed by the diffusion of pentane vapor to a 1,1,1-trichloroethane solution of 1 synthesized by the C–H borylation method. The crystal structure confirmed that the C–H borylation proceeded regioselectively at the least hindered C–H

Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

• Ryo Takishima,
• Yuji Nishii,
• Tomoaki Hinoue,
• Yoshitane Imai and
• Masahiro Miura

Beilstein J. Org. Chem. 2020, 16, 325–336, doi:10.3762/bjoc.16.32

• numerous attempts for obtaining crystals suitable for the X-ray analysis. Based on these observations, it is reasonable to conclude that the tert-butyl substituents effectively restricted the stacking structure to the specific conformations, thereby facilitating the assembly of well-ordered aggregates in

• -state structures were investigated by X-ray diffraction analysis to find well-ordered intermolecular stacking structures within the crystals. Experimental General All manipulations were performed under N2 using standard Schlenk techniques unless otherwise noted. DMF was dried and deoxygenated by a Glass

• . Compound 4b: Synthesized similarly to 4b from 3b (254 mg, 0.30 mmol). Purified by silica gel column chromatography (eluent: hexane/EtOAc 4:1) and GPC to give the title compound as pale yellow solid; (S)-4b (45.4 mg, 18% yield), (R)-4b (30.2 mg, 12% yield). Single crystals suitable for the X-ray analysis

Absolute configurations of talaromycones A and B, α-diversonolic ester, and aspergillusone B from endophytic Talaromyces sp. ECN211

• Ken-ichi Nakashima,
• Junko Tomida,
• Takao Hirai,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 290–296, doi:10.3762/bjoc.16.28

• in good agreement with those of 1 (Figure 3b), the absolute configuration of 2 was also assigned to be R. Single crystals of α-diversonolic ester (3) were obtained as colorless prisms by vapor diffusion with acetone/n-hexane, and single-crystal X-ray diffractometry determined the structure shown in

•  4b). This is the first experimental evidence that corroborates the absolute configurations of 3 and 4, compounds that were reported previously without evidence for this stereochemistry. We also obtained single crystals of glauconic acid (5) as prisms by slow evaporation in CH2Cl2/n-hexane at 10 °C. X

• :1, v/v) as eluent. The fractions were pooled according to TLC analysis to yield nine combined fractions (F1–9). F2 was subjected to ODS column chromatography with MeCN/H2O (stepwise gradient, 3:7, 2:3, and 1:1, v/v) to yield 1 (45.3 mg). F4 was recrystallized from CH2Cl2 to obtain crude crystals of

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

• Yana I. Sakhno,
• Maryna V. Murlykina,
• Oleksandr I. Zbruyev,
• Anton V. Kozyryev,
• Svetlana V. Shishkina,
• Dmytro Sysoiev,
• Vladimir I. Musatov,
• Sergey M. Desenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

• Yana I. Sakhno Maryna V. Murlykina Oleksandr I. Zbruyev Anton V. Kozyryev Svetlana V. Shishkina Dmytro Sysoiev Vladimir I. Musatov Sergey M. Desenko Valentyn A. Chebanov Division of Chemistry of Functional Materials, State Scientific Institution “Institute for Single Crystals” of National Academy