Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• optimization (Table S4, Supporting Information File 1), solubility issues hindered the formation of a concentrated solution (>0.8 M). The crystallization of iPrMgBr in the collection flask forced us to reduce the initial concentration of the organic halide to 0.9 M, yielding iPrMgBr (0.75 M, 82%, note: the

• GC–MS, after being washed with pentane at 0 °C and dried under vacuum, showed no evidence of organic compounds. It seemed that TMPMgCl⋅LiCl coordinated less LiCl than the corresponding iPrMgCl⋅LiCl and triggered LiCl crystallization. To solve this issue, the packed-bed column temperature was decrease

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

• dichloromethane as the eluent. Analytically pure samples of tetrahydrothiophenes 9 were obtained by crystallization from petroleum ether or hexane with a small amount of dichloromethane. The diastereoselectivity of the studied reactions was determined by integration of the crude 1H NMR. Preliminary purification

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• efforts, several molecular designs have been proposed as alternatives, particularly the use of pure organic phosphorescent molecules [22]. For example, methyl 4-bromobenzoate (Figure 1B) exhibits phosphorescence in the crystalline state via nonradiative ISC to the T1 state owing to crystallization-induced

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

• 1, that only showed a crystallization signal (TCR = 138 °C) during the cooling scan. The 10% weight-loss temperature (TD−10%) of the quinazoline-based compounds decreased in the order of 3 (409 °C) > 2 (345 °C) > 1 (247 °C). For compounds 1 and 2 a complete weight loss was observed in the TGA

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

• before the crystallization, as confirmed by powder diffraction data collected at room temperature for the white precipitate obtained from the mixed water solutions of TAPM and NDS. Space group P21/c, a = 20.9609(10) Å, b = 19.7563(9) Å, c = 22.6642(10) Å, β = 92.694(3)°, cell volume = 9375.1(8) Å3. When

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

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

• Supporting Information File 1). While this feature is an interesting take on the selective homo interactions, the explanation of this motif formation is potentially more mundane in this case. Considering that during the crystallization process, the spontaneous formation of the homo or hetero π-stacking of

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

• at room temperature. What is more, we attempted to crystallize at least one derivative to confirm the absolute stereochemistry of the obtained compounds. In order to obtain a single crystal suitable for X-ray diffraction studies, various crystallization techniques were tested [37][38

• ]. 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

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

• vapour diffusion method using CHCl3/hexane conditions. Figure 2 shows the crystal structure of 5a. The crystal was obtained as a racemic compound containing a pair of two enantiomers defined by bowl chirality [26], as a result of the rapid bowl inversion under the crystallization conditions. 5a formed a

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

• ]. However, the crude product was not completely purified by Soxhlet extraction and by crystallization in our hands. The borylation reaction of hardly soluble crude quaterrylene gave a deep green suspension. MALDI mass spectrometry of the reaction mixture detected an ion peak at m/z = 1004.5018 (calcd for

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• preferably refers to the solubility in the surrounding matrix, while undesirable events such as aggregation are of minor importance. In the worst case, it can also result in crystallization of the cyanine in the matrix under certain storage conditions such as high humidity and/or elevated temperatures

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• . Finally, the desired ligands were obtained by palladium-catalyzed phosphorylation with triphenylphosphine in DMF [92]. Resolution with palladium amine complexes and subsequent crystallization resulted in the enantiomerically pure ligands 95. C2-Symmetric atropisomeric diphosphines are among a diverse

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

• absolute configurations of the new derivatives 1 and 2 using extensive spectroscopic analyses as well as single-crystal X-ray diffractometry. Our crystallization efforts resolved the absolute configuration of α-diversonolic ester (3) and its derivatives, which had not been clarified previously

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

• halogen acceptors was also investigated. Diffusion of ether into the mixture of 4,4'-bipyridine (bpy) and 2-BF4 in dichloromethane leads to the crystallization of 2-BF4·0.5bpy (Figure 8). It crystallizes in the monoclinic space group P21/c. The acceptor 4,4'-bipyridine provides a complementary link for 1D

Photoreversible stretching of a BAPTA chelator marshalling Ca²⁺-binding in aqueous media

• Aurélien Ducrot,
• Arnaud Tron,
• Robin Bofinger,
• Ingrid Sanz Beguer,
• Jean-Luc Pozzo and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273

• with toluene (3 × 100 mL). A final crystallization from EtOH yielded the title compound (4.69 g, 89%). 1H NMR (CDCl3, 200 MHz) δ 7.30–7.42 (m, 10H, CHAr), 6.75 (d, J = 9.2 Hz, 2H, CHAr), 6.43–6.48 (m, 4H, CHAr), 4.97 (s, 4H, CH2), 4.18 (s, 4H, CH2), 4.14 (s, 8H, CH2), 4.06 (q, J = 7.2 Hz, 8H, CH2

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• supramolecular palladium complexes caused immediate crystallization [22]. Moreover, azobenzenes have been used to functionalize both the interior [23] and exterior [24] of SCCs to photochemically control guest binding and release. Furthermore, incorporation of dithienylethene into the ligands connecting the

A photochemical determination of luminescence efficiency of upconverting nanoparticles

• Baptiste Amouroux,
• Clément Roux,
• Jean-Claude Micheau,
• Fabienne Gauffre and
• Christophe Coudret

Beilstein J. Org. Chem. 2019, 15, 2671–2677, doi:10.3762/bjoc.15.260

• volatile solvents removal, (iii) the high temperature crystallization step for 90 minutes. Spherical nanoparticles of 21.8 ± 1.3 nm were collected. Crystal quality was assayed by XRD and only the hexagonal β-phase could be detected (Supporting Information File 1). These particles are kept well dispersed in

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

• fractionating crystallization. Structure determination by X-ray diffraction analysis revealed marked conformational differences around the CH–C(O–) single bond of E and Z-isomers and extended charge delocalization in the anionic part. Keywords: betaines; multi-component reactions; N-triflylamides; phospha

• E-diastereoisomers, others as E/Z mixtures. In some cases, the two diastereoisomers were separated by fractionating crystallization from a mixed-solvent solution. In the case of 3a, a trace amount (≈2%) of the Z-isomer was detected in the reaction mixture by 1H NMR (the chemical shift of the

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• (III) chloride in methanol in 88% yield (Scheme 1). The synthesis of allylic alcohol 11, a regioisomer of 6, started again from (1R)-α-pinene (1, Scheme 2). Hydroboration of (1R)-α-pinene with borane–dimethyl sulfide adduct (BMS) and crystallization of the product diisopinocampheylborane (dIpc2BH, 84

• added to the reaction mixture and the solution was filtered through a pad of celite. The precipitate was washed with another portion of warm toluene (10 mL). The solvent was removed using a rotary evaporator to give the phosphine oxide. After crystallization from heptane, phosphine oxide 21 (1.612 g, 92

Indium-mediated C-allylation of melibiose

• Christian Denner,
• Manuel Gintner,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2019, 15, 2458–2464, doi:10.3762/bjoc.15.238

• –124 °C (methanol used for crystallization); 1H NMR (600.25 MHz, CDCl3, 25 °C) δ 5.653 (dddd, 3J8,9a = 17.0 Hz, 3J8,9b = 10.2 Hz, 3J8,7b = 7.3 Hz, 3J8,7a = 6.9 Hz, 1H, H-8), 5.449 (dd, 3J4’,3’ = 3.4 Hz, 3J4’,5’ = 1.2 Hz, 1H, H-4’), 5.416 (dd, 3J3,2 = 7.5 Hz, 3J3,4 = 3.3 Hz, 1H, H-3), 5.308 (dd, 3J4,5

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

• (H2B(pz)2)2”, with its β-keto ester moiety acting as a second coordination site. Slow crystallization yielded a tetranuclear Fe(II) complex 9, where the base dimeric unit is expanded by an unprecedented trimethoxypyrazolylborate bridging group. The photocyclization of iron complexes is inhibited due to

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

• spectra were measured on a GC–MS Varian 1200L (ionizing voltage 70 eV, direct input of the sample) instrument. Elemental analysis was realized on a EuroVector EA-3000. Analytical samples of the compounds were obtained by crystallization from water and further drying at room temperature in air. Microwave

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• subsequent cyclization unlikely. Crystal structure of CotB2wt·Mg2+3·F-Dola resembles the closed, active conformation The structure of CotB2wt·Mg2+3·F-Dola has been obtained by co-crystallization of CotB2wt and FGGDP (PDB-ID 6GGI; [37]), representing the closed, active conformation. Fluorinated substrates

• , such as FGGDP, have been used for the crystallization of other TPSs and have been shown to stick to the active site without undergoing cyclization, trapping the enzyme in a closed state [52][53]. Comparing the overall structure of CotB2wt·Mg2+3·F-Dola to the open conformation of CotB2 reveals major

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

• state, as envisioned. Possible reasons could be assigned to substituent effects as demonstrated by Simeth et al. [62]. As recently reported by Schehr et al., reducing agents like DTT, used to prevent enzyme oxidation in crystallization mixtures or in vitro assays, can reduce azo dyes to hydrazine

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