[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• compounds failed to give single crystals for X-ray analysis. The presence of an oxygen atom attached to the phosphorus atom in the products could be deduced based on 1H and 13C NMR analysis. In the 1H NMR spectra of phosphine sulfide 12, the chemical shifts of the signals belonging to the aromatic protons

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• evaporation of dichloromethane solution. The treatment of 2-I with 2 equivalents iodine or 4 equivalents iodine afforded triazolium polyiodide 2-I.1.5I2 and 2-I.3.5I2, respectively. The single crystals were obtained by slow diffusion of ether into a dichloromethane solution. The crystal X-ray analyses of 2-I

• the former shows a boat conformation and the latter forms a rectangle conformation. Triazolium salts form a linear polymer with polyiodide. 2-BF4 forms co-crystals with 4,4'-bipyridine via halogen bonding. DFT calculation results show that the σ holes of 4,5-diiodo-1,2,3-triazolium is similar to the σ

• ), 110.0, 21.4, 17.4; anal. calcd. for C22H22F3I2N3O2 (671.24): C, 39.37, H, 3.30, N, 6.26%; found: C, 39.51, H, 3.49, N, 6.18%. 2-I.1.5I2: 2-I (35 mg, 0.05 mol) and I2 (25 mg, 0.1 mmol) were mixed in dichloromethane (6 mL) in a round bottom flask. The single crystals were obtained by slow diffusion of

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• 12 led to single crystals suitable for X-ray crystallography. Its analysis (Figure 3) not only confirmed the structure, but in addition showed a well-organized crystal packing (Figure 4) where the alternate disposition of the molecules displayed a parallelism between the p-bromophenyl groups as well

• as between the triazole rings, and therefore the presence of multiple intermolecular π–π stacking and π–bromine [19] interactions. This compound precipitated in the presence of any amount of water and gelled only in DMSO at a low temperature. Compound 10 produced pseudo-crystals in DMSO/H2O (1:1, v/v

Design, synthesis and investigation of water-soluble hemi-indigo photoswitches for bioapplications

• Daria V. Berdnikova

Beilstein J. Org. Chem. 2019, 15, 2822–2829, doi:10.3762/bjoc.15.275

• ), 136.0 (1C, C-4), 153.9 (1C, C-2), 159.6 (1C, C-14), 186.0 (1C, C-8) ppm); Anal. calcd for C16H13NO2: C, 76.48; H, 5.21; N, 5.57; found: C, 76.31 H, 5.15; N, 5.50 %; ESIMS (MeOH, m/z): 250 [Z-1b − H]−. (Z)-2-(3,4-Dimethoxybenzylidene)indolin-3-one (Z-1c) Orange crystals, yield 66% (211 mg, 0.75 mmol); mp

Diversity-oriented synthesis of spirothiazolidinediones and their biological evaluation

• Sambasivarao Kotha,
• Gaddamedi Sreevani,
• Lilya U. Dzhemileva,
• Milyausha M. Yunusbaeva,
• Usein M. Dzhemilev and
• Vladimir A. D’yakonov

Beilstein J. Org. Chem. 2019, 15, 2774–2781, doi:10.3762/bjoc.15.269

• , the formazan crystals were dissolved in 150 μL of DMSO, and the absorbance was determined at 595 nm using a microplate spectrophotometer. The IC50 value was determined from plots of percent viability against the dose of the compound added. Cytotoxicity assay: Viability (live/dead) assessment was

Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

• Nadezhda S. Demina,
• Nikita A. Kazin,
• Nikolay A. Rasputin,
• Roman A. Irgashev and
• Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

• crystals of some of these compounds, however, all of them formed powdery precipitates. Therefore, N-functionalization of compound 6d was carried out with benzyl bromide in the presence of NaH (Scheme 4). The resulting benzyl derivative 7d was crystallized from ethyl acetate to give crystals, which were

Unexpected one-pot formation of the 1H-6a,8a-epiminotricyclopenta[a,c,e][8]annulene system from cyclopentanone, ammonia and dimethyl fumarate. Synthesis of highly strained polycyclic nitroxide and EPR study

• Sergey A. Dobrynin,
• Igor A. Kirilyuk,
• Yuri V. Gatilov,
• Andrey A. Kuzhelev,
• Olesya A. Krumkacheva,
• Matvey V. Fedin,
• Michael K. Bowman and
• Elena G. Bagryanskaya

Beilstein J. Org. Chem. 2019, 15, 2664–2670, doi:10.3762/bjoc.15.259

• 4:1). 1: 70 mg (5%); colorless crystals; mp 146.8–148.4 °C; IR (KBr): 3298 (N-H), 1734, 1718 (C=O); 1H NMR (400 MHz, CDCl3, δ) 1.08–1.16 (m, 1H), 1.35–1.48 (m, 3H), 1.49–1.57 (m, 1H), 1.60–1.69 (m, 3H), 1.70–1.76 (m, 1H), 1.84–1.90 (m,1H), 1.91–1.98 (m, 2H), 1.99–2.08 (m, 3H), 2.14–2.20 (m, 1H

• silica gel (hexane/ethyl acetate 4:1). 2: 56 mg (48%); red crystals; mp 127.0 °C dec, IR (KBr): 3438 (O-H) 1730 (C=O); X-ray: triclinic system, P-1, a = 8.2240(5), b = 10.9423(6), c = 11.4515(8) Å, α = 83.440(3), β = 75.611(3), γ = 83.119(2)º, V = 987.17(11) Å3, Z = 2, 2θmax = 27.292°, 4388 independent

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• incubated with 150 μL of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) solution (0.5 mg mL−1) in cell culture medium for 4 h in the dark at 37 °C (MTT is reduced by metabolically active cells to insoluble purple formazan dye crystals that accumulate inside the cell cytoplasm

• ). Afterwards, the MTT solution is removed and 200 μL of DMSO are added to all samples to solubilize the formazan dye crystals. The plate was read in spectrophotometer and the optimal wavelength for absorbance was 570 nm. The MTT assay was performed in triplicate and also made three independent assays. The cell

Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis

• Heather J. Lacey,
• Cameron L. M. Gilchrist,
• Andrew Crombie,
• John A. Kalaitzis,
• Daniel Vuong,
• Peter J. Rutledge,
• Peter Turner,
• John I. Pitt,
• Ernest Lacey,
• Yit-Heng Chooi and
• Andrew M. Piggott

Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256

• C22H35O5+ [M – H2O + H]+, 379.2479; found, 379.2473. Crystallography Crystals suitable for single crystal X-ray diffraction analysis were obtained for 1, 4 and 9, providing confirmation of the spectroscopic structural elucidation. Indirect confirmation of the structures of 2 and 3 was obtained following

• their conversion to 4-bromobenzoyl ester derivatives, with substitution at the C-9 and C-1 hydroxy groups respectively, and the growth of crystals of these derivatives (2b and 3b). The X-ray diffraction data obtained from single crystals of 4 and 9 did not allow a definitive determination of their

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

• Vito A. Fiore,
• Chiara Freisler and
• Gerhard Maas

Beilstein J. Org. Chem. 2019, 15, 2603–2611, doi:10.3762/bjoc.15.253

• usually colorless, while the Z-isomers have a yellow shade. As an exception, E-3f was obtained as dark red needle-shaped crystals, in contrast to pale yellow blocks of Z-3f. All betaines could be stored unchanged at least for a year under a dry atmosphere. They appear to be somewhat hygroscopic, as the

Synthetic terpenoids in the world of fragrances: Iso E Super^® is the showcase

• Alexey Stepanyuk and
• Andreas Kirschning

Beilstein J. Org. Chem. 2019, 15, 2590–2602, doi:10.3762/bjoc.15.252

• challenges to be solved. Hydrophilic and hydrophobic interactions with the unpolar lipid layer make the tendency to yield suitable crystals even more difficult. Nevertheless, Palczewski and co-workers were able to crystallise the first GPCR (G-protein-coupled receptor) in 2000 confirming the previously

Safe and highly efficient adaptation of potentially explosive azide chemistry involved in the synthesis of Tamiflu using continuous-flow technology

• Cloudius R. Sagandira and
• Paul Watts

Beilstein J. Org. Chem. 2019, 15, 2577–2589, doi:10.3762/bjoc.15.251

• concentrated in vacuo to afford pure compound 7 as white crystals. Solid: mp 136.9–138.2 °C (Lit. value [9] mp. 136.6–137.7 °C); FTIR (cm−1) ν: 3266, 2971, 2099, 1713, 1658, 1558, 1249, 1075; 1H NMR (400 MHz, CDCl3) δ 0.91 (m, 6H), 1.31 (t, J = 7.1 Hz, 3H), 1.42–1.63 (m, 4H), 2.10 (s, 3H), 2.18–2.33 (m, 1H

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1’-diacetylenic ferrocenes

• Celine Bittner,
• Dirk Bockfeld and
• Matthias Tamm

Beilstein J. Org. Chem. 2019, 15, 2534–2543, doi:10.3762/bjoc.15.246

• solutions of 1a and 1b after layering with pentane or hexane, respectively, crystals suitable for X-ray diffraction analysis could be obtained. The corresponding ORTEP drawings are given in Figure 3 and Figure 4. Ferrocene 1a crystallises in the orthorhombic space group Pca21, while the analogues compound

• disorder on the iron position. Unfortunately, no single crystals for X-ray diffraction analysis could be obtained with such disorder being absent. For the catalytic RCAM (Scheme 1), the substrates 1a and 1b were dissolved in toluene at high dilution (4.5 mM), and the catalyst MoF6 (2 mol %) was added as a

• experimental section in Supporting Information File 1). Crystals of 2a suitable for X-ray diffraction analysis could be obtained from a hot saturated solution in toluene after cooling to −28 °C. An ORTEP drawing is given in Figure 5. The ferrocenophane 2a crystallises in the orthorhombic space group Pbcn with

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• for 1a, AgOTFA for 1b, AgNO3 for 1c and PPh3AgOTf for 1d. Crystallographic structures of silver complexes Single crystals of 1a, 1c and 1d suitable for X-ray diffraction analysis were grown from the slow diffusion of hexane into a solution of each complex in dichloromethane. Interestingly, each

• )–1 ligands). The X-ray diffraction of monocrystals 1a revealed the formation of (R,S–1)2·(AgOTf)2 macrocycles driven by silver(I) coordination (Figure 1). The two ligands are facing through the coordination of one syn-thioether group to the same silver cation. Two different crystals were isolated and

• ) cation was coordinated to two sulfur atoms with (R)- and (S)-configuration, respectively (head-to-tail ligand coordination mode). These diastereoisomeric crystals presented a slightly different spatial arrangement. The head-to head macrocycle 1a had a parallelepiped shape (Figure 1a): the interplanar

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• . Crystals suitable for X-ray structure were obtained in a fritted U-shape tube by the slow diffusion of methanol solutions of in situ-prepared “Fe(H2B(pz)2)2“ and diarylethene 6. Unexpectedly, we have found that the structure of the product depends on the reaction time. Reproducible crystals isolated after

• growing for 1 month and less – a dinuclear complex 8, and unique crystals after 2-year storage – a tetranuclear complex 9, have different molecular structures (Figure 3). Both complexes represent unusual cyclic complexes, comprising two diarylethene ligands and two or four iron(II) ions in 8 and 9

• ). Apparently, this product is the result of destruction of bis(pyrazolyl)borate moieties of complex 8 by methanol. Species 9 crystallizes as red, block-shaped crystals in the triclinic P−1 space group with one molecule in the unit cell. The crystal structure reveals two pairs of differently substituted iron

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• protons are correlated with H1, H3, and H7, whereas the Hc protons are correlated with H4, H8, and H5 (see the partial NOE spectrum in Figure 2; see below for further analysis of this spectrum). Single crystals of (E-1)22 suitable for X-ray diffraction were obtained by slow water evaporation from an

• ; the strongest correlations were found between Ha and H1 and between Hc and H4 (Figure S20, Supporting Information File 1; note that the opposite was found for the E isomer, cf. Figure 2). Despite repeated efforts, we did not succeed in preparing crystals of the (Z-1)2 inclusion complex suitable for X

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

• Irina G. Tkachenko,
• Sergey A. Komykhov,
• Vladimir I. Musatov,
• Svitlana V. Shishkina,
• Viktoriya V. Dyakonenko,
• Vladimir N. Shvets,
• Mikhail V. Diachkov,
• Valentyn A. Chebanov and
• Sergey M. Desenko

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

• Irina G. Tkachenko Sergey A. Komykhov Vladimir I. Musatov Svitlana V. Shishkina Viktoriya V. Dyakonenko Vladimir N. Shvets Mikhail V. Diachkov Valentyn A. Chebanov Sergey M. Desenko State Scientific Institution "Institute for Single Crystals", National Academy of Sciences of Ukraine, Nauky Ave 60

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• . In addition, it shows turn-off type fluorescence switching in an aprotic solvent and in crystals. The fluorescence is quenched as the content of closed-ring isomers increases upon UV light irradiation. Conclusions: A diarylethene containing an ESIPT functional group was prepared. It showed

• crystals are inherently capable of photo-reversible luminescence switching because the electronic structures of photochromic molecules reversibly change upon photoisomerization [13][14]. However, such a fluorescent system in condensed phase emits fluorescence often absorbed in adjacent molecules, therefore

• spectrofluorophotometer equipped with ILF-533 integral sphere. KEYENCE VHX-500, VH-S30, VH-Z20 were used to monitor the crystals. For the UV light irradiation, KEYENCE UV-400, UV-50H (λ = 365 nm), Spectronics Corporation Westbury, New York, USA Spectro Line Highest Ultraviolet Intensity Guaranteed (100 V, 40 A, λ = 313

Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors

• Christoph W. Grathwol,
• Nathalie Wössner,
• Sören Swyter,
• Adam C. Smith,
• Enrico Tapavicza,
• Robert K. Hofstetter,
• Anja Bodtke,
• Manfred Jung and
• Andreas Link

Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214

• reduced pressure. The formed precipitate was collected by filtration and recrystallized from EtOAc. The product was obtained as colourless crystals (0.55 g, 2.45 mmol, 49%): Rf = 0.25 (cyclohexane/THF 1:1); mp: 196.4 °C; 1H NMR (400 MHz, DMSO-d6) δ (ppm) 8.93 (d, J = 2.0 Hz, 1H), 8.90 (d, J = 2.1 Hz, 1H

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• −, Br− and I− were found as 4.4 × 101 M−1, 1.7 × 101 M−1, 8.5 M−1, respectively. Thus, the interaction of 1,2,3-triazolium CH is decreasing with increasing halide size. Besides, the complexes of halides with the macrocycles were shown to have visible charge-transfer absorptions in the molecular crystals

• . Thus, these complexes could be useful for designing functional molecular crystals and materials which can be applied for the study of photoinduced electron transfer and energy conversion towards application in the field of molecular electronics. 3. Molecular reactors Designing synthetic host systems

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• THTAA Derivative 3 was prepared from 2,5-dihydroxy-p-benzoquinone and ethylenediamine as brownish-yellow solid according to the recommended procedure (Scheme 1) [8]. Crystallization from butyl acetate produced yellow crystals of THTAA (3) in about 50% yield, still slightly brownish, along with the

• observed upon attempts to sublime the brown byproduct about 200–210 °C affording colorless crystals. The NMR spectrum corresponded to 5 (described, sometimes, as light yellow solid [18][19]). It is worth of noting that sublimed 5 does not fluoresce so that previously observed fluorescence [20] and

• -donating ethylenediamino moiety toward the electron-accepting ethylenediimino moiety in 3 and delocalization of the positive charges in 6a and 7a (Scheme 3), and are not artifacts arising from the strong intermolecular interactions within the crystals. Losing aromaticity, the benzene ring is becoming less

Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• the Supporting Information File 1, Figures S6–S8). In addition to that, slow evaporation of an equimolar solution of U1 and A2 in benzene furnished red-orange single crystals suitable for X-ray analysis of a [2 + 2] halogen-bonded box, U1···A2, over the course of a few days in quantitative yield

Attempted synthesis of a meta-metalated calix[4]arene

• Christopher D. Jurisch and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195

• literature report [32]). This was presumably due to ruthenium undergoing a reductive elimination and the chloride remaining on the triazolium moiety. Crystallization also proved to be futile after many attempts under many different conditions. The only crystals that formed were either found to be the

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• -corona[6]arenes in the solid state, high quality single crystals of 3a were grown at room temperature from diffusion of diethyl ether vapor into the solution of 3a in acetonitrile. X-ray diffraction analysis revealed that the macrocycle 3a adopted an interesting conformation. As depicted in Figure 1, it

• ability of 3a to bind various anion species in gas phase. To our delight, host molecule 3a co-crystalized with n-Bu4NX (X = Cl, Br) from diffusion of diethyl ether vapor into ethyl acetate solution at ambient temperature to give single crystals of the host–guest complexes (n-Bu4NX)3-3a (X = Cl, Br). X-ray

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• period of 72 h during which the crystals were formed. These were collected by filtration over a frit and washed with hexanes obtaining 7.9 g of the matter that was analyzed by TLC and LRMS analyses. We observed that the matter consisted, in particular, of two terpene-type compounds, compound 1 and 2, and