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

Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

• Man-Man Wang,
• Hao Huang,
• Lei Shu,
• Jian-Min Liu,
• Jian-Qiu Zhang,
• Yi-Le Yan and
• Da-Yong Zhang

Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25

• Supporting Information File 1. The chemical structures of all title compounds were confirmed by 1H and 13C NMR spectroscopic analyses and HRMS spectrometric analyses. X-ray diffraction Single crystals of compounds I18 and III4 were cultivated for structure validation. Compound I18 was recrystallized from a

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• has not been reported previously [CCDC No.: 1868146]. The crystals of 6 were obtained by slow evaporation of methanol/dichloromethane and were found to be of the monoclinic crystal system with space group C2/c (Figure 7). The crystal structure shows that the fluorinated phenyl ring is at a torsion

The use of isoxazoline and isoxazole scaffolding in the design of novel thiourea and amide liquid-crystalline compounds

• Itamar L. Gonçalves,
• Rafaela R. da Rosa,
• Vera L. Eifler-Lima and
• Aloir A. Merlo

Beilstein J. Org. Chem. 2020, 16, 175–184, doi:10.3762/bjoc.16.20

• Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal Institute of Chemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil 10.3762/bjoc.16.20 Abstract A series of novel thiourea and amide liquid crystals containing 5-membered isoxazoline and isoxazole rings

• crystals containing hydrogen bonds may exhibit a wide variety of phase polymorphism depending on the length of the chain, type of bonding and the functional groups involved [12][28][29][30]. Many liquid crystalline compounds have been developed exploring the ability of hydrogen bonding formation between

Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

• Afef Mabrouki,
• Malek Fouzai,
• Armand Soldera,
• Abdelkader Kriaa and
• Ahmed Hedhli

Beilstein J. Org. Chem. 2020, 16, 149–158, doi:10.3762/bjoc.16.17

• moments were also investigated. Keywords: dipole moment; fluorine; liquid crystal; oxadiazole; Introduction Liquid-crystalline (LC) materials have been known for over a century [1]. It is clear that architecture and functionalization are essential aspects in molecular engineering of liquid crystals [2

• the fluorine atom leads to a subtle modification of properties such as melting point, mesophase morphology, transition temperatures, optical anisotropy, dielectric anisotropy, and visco-elasticity [5][6][7][8][9][10]. Therefore, many fluorinated liquid crystals have been prepared, and the fluoro

• -substitution effect has been well studied, especially in the fluoroaromatic derivatives [11][12][13]. Additionally, the mesomorphic properties of liquid crystals depend strongly on the nature of the terminal chains that are present. A terminal perfluorocarbon chain present in a LC molecule causes stiffening

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• essentially zerovalent Ru nanoparticles promotes their catalytic ability towards several challenging reactions, such as CO oxidation [67][68] and hydrogen evolution [69]. Interestingly, pristine Ru(0) single crystals have been reported to perform poorly in these reactions when compared to the surface-oxidised

Reversible photoswitching of the DNA-binding properties of styrylquinolizinium derivatives through photochromic [2 + 2] cycloaddition and cycloreversion

• Sarah Kölsch,
• Heiko Ihmels,
• Jochen Mattay,
• Norbert Sewald and
• Brian O. Patrick

Beilstein J. Org. Chem. 2020, 16, 111–124, doi:10.3762/bjoc.16.13

• single crystals after slow evaporation, their structure was determined by single crystal X-ray diffraction (XRD) analysis (Figure 8, cf. Supporting Information File 1). The cyclobutane 4b crystallized from water in the monoclinic space group P21/n, and the derivative 4c crystallized from water in the

[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