DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• mechanochemistry [5][6] mainly focuses on conducting synthetic transformations in solid-state or solvent-free conditions. Mechanochemistry is one of the emerging avenues in chemistry that can make the world more sustainable by following the “Twelve Principles of Green Chemistry” [2]. Mechanochemistry is one of the

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

• toluene solutions as well as 1 wt % PMMA (poly(methyl methacrylate)) films. The solid-state samples were prepared by dissolving the compounds and polymer or host material at appropriate ratios in toluene solution and then wet-casting the solutions on quartz substrates. The absorption spectra were recorded

• 49 ms integration time. Solid-state samples were mounted in a closed cycle He cryostat (Cryo Industries 204 N) for PL measurements in oxygen-free conditions. Quantum chemical calculations were carried out by using density functional theory at the B3LYP/6-31G(d) level as implemented in a software

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• [17]. It is noted that the solubility of the D–A compound 1 in organic solvents is lower than that of the D–A–D compound, indicating a more aggregated state of the D–A molecules in the solid state, due to less steric hindrance on the acceptor plane arising from breaking the symmetry. The synthesized

• ], indicating a dominant non-radiative decay of the excited state for the D–A type compound, which was supported by the theoretical calculations (vide infra). In the solid state, the D–A compound 1 showed an emission at around λem = 560 nm with a very low ΦPL (<0.1) (Figure S1 in Supporting Information File 1

• ). The PL spectrum is similar to that in a CBP host matrix (vide infra). The compound 1 showed an aggregation-induced emission (AIE) behavior in a THF/water system, showing a more red-shifted emission peak at around λem = 600 nm when compared with the as-prepared solid state (Figure S2 in Supporting

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• ) and one sulfinamide oxygen (O4). Atom numbering as in Figure 1. The asymmetry of such interactions reflects the intrinsic asymmetry of the solid-state conformer. Supporting Information Supporting Information File 42: Experimental part, NMR spectra and christallographic data of compound 2a.

Trichloroacetic acid fueled practical amine purifications

• Aleena Thomas,
• Baptiste Gasch,
• Enzo Olivieri and
• Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

• naphthalene or 2-methoxynaphthalene were chosen as representative model impurities given their potential π-stacking ability and solid state at room temperature. Consequently, they are more challenging to separate from the generated amine salts, demonstrating the power of the method. Aside from secondary

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• exhibiting solid-state fluorescence, although the fluorescence partially disappears in solution, and there is a large shift to red and blue [98][99]. Carbon–carbon bond formation The main steps in a synthesis usually involve C–C bond formation, which is usually the main reaction step, or functional group

• quinoid type to study their photophysical properties in solution and in the solid-state, Ooyama and co-workers [106] studied a synthetic route for the preparation of compounds with the tricyclic benzo[c]carbazol-6-one skeleton. The strategy used was through the reaction to β-NQS 18 with a bifunctional

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• achieved by solid-state synthesis. Our synthetic strategy could synthesize the target peptide in high yield with good purity Keywords: antimalarial; highly methylated polypeptides; hoshinoamides; total synthesis; Introduction Malaria is an insect-borne infectious disease caused by parasites of the genus

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• for compound 3ba in the solid state (Figure 2). The compound crystallized in the P21/c space group, and it was possible to verify that the dihedral angles between the substituent (C6H5) and quinoline ring (N1–C2–C21–C26) were 18.1°. The dihedral angles between the quinoline ring and the substituent

A straightforward conversion of 1,4-quinones into polycyclic pyrazoles via [3 + 2]-cycloaddition with fluorinated nitrile imines

• Greta Utecht-Jarzyńska,
• Karolina Nagła,
• Grzegorz Mlostoń,
• Heinz Heimgartner,
• Marcin Palusiak and
• Marcin Jasiński

Beilstein J. Org. Chem. 2021, 17, 1509–1517, doi:10.3762/bjoc.17.108

• case, the subsequent elimination step leading to an aromatized product cannot take place. All products of the type 9 are colored, typically pale yellow, both in the solid state and in solution. The UV–vis spectroscopic analysis of the naphthoquinone-derived series (compounds 9a–h) revealed less intense

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• shown a significant hydrophobization effect on bulk g-CN [45], so that a similar strategy is targeted for the present case in hydrogel systems (Scheme 2). After adequate light irradiation followed by a facile purification step, the resulting sample (HGCM-vTA) and HGCM were investigated via solid-state

• , respectively, and left overnight. Released contents of each cation were analyzed via ICP-OES. Characterization: Fourier transform infrared (FTIR) spectra were acquired on a Nicolet iS 5 FT-IR spectrometer. Solid-state ultraviolet−visible (UV−vis) spectroscopy for grinded samples was performed via a Cary 500

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• , Supporting Information File 2). Additionally, the complex 17 in a solid state is also stabilized with π–π stacking interactions between the 1,2-diazine moieties and the pyridin-2-yl substituents of the ligands (Figure S1b, Supporting Information File 2). The FTIR spectrum recorded for complex 17 confirmed

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

• Lukáš Marek,
• Lukáš Kolman,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

• solid state by X-ray diffraction. The important role of the intramolecular hydrogen bond fixing the (Z)-configuration has also been observed in the crystal structures of other 3-aminomethylidene derivatives containing a primary or secondary nitrogen [14][49][50][51][52]. The (Z)-configuration of the

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• -quinone 3a, which was previously reported by us [14]. The product 6a is air-stable at ambient conditions both in solid state and in solution. According to X-ray data, the 1,3-dithiole ring in the molecule is almost planar, its geometry is typical of 1,3-dithiole-2-thione species [26][27][28] (Figure S1 in

Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding

• Subrata Nath,
• Alexander Kappelt,
• Matthias Spengler,
• Bibhisan Roy,
• Jens Voskuhl and
• Michael Giese

Beilstein J. Org. Chem. 2021, 17, 124–131, doi:10.3762/bjoc.17.13

• supramolecular entities in the solid state. This effect was also confirmed by the fluorescence behaviour (see paragraph on photophysical properties) and affects mainly the transition from the nematic to crystalline phase. In addition, it was observed that only assemblies with an odd number of carbon atoms in the

• , enantiotropic phase transitions were observed exclusively for NO2-C10∙∙∙F4Az, indicating a different solid-state arrangement of the azo compounds compared to the stilbazole-based assemblies. The mesomorphic properties of all nitro compounds and the assemblies are summarised in Figure 3 and Table 1. The strength

• interactions and packing in the solid state and adds to the shift of the crystallisation temperature. Photophysical studies Recently, our group has shown that self-assembly provides an efficient way to tune fluorescence behaviour of liquid crystalline materials [21]. Phenolic thioethers showing aggregation

Circularly polarized luminescent systems fabricated by Tröger's base derivatives through two different strategies

• Cheng Qian,
• Yuan Chen,
• Qian Zhao,
• Ming Cheng,
• Chen Lin,
• Juli Jiang and
• Leyong Wang

Beilstein J. Org. Chem. 2021, 17, 52–57, doi:10.3762/bjoc.17.6

• ; inversion of CPL handedness; Tröger's base; Introduction Recently, much effort has been devoted to constructing luminescent materials with efficient high emission in the solid state [1][2][3]. More and more types of fluorophores with aggregation-induced emission (AIE) characteristics have been discovered

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• building blocks in such systems results in a certain degree of control [26][27], yet the PDI nanobelts do not remain free-floating in solution and normally are characterized as solid-state materials [28], limiting the processability of the nanocrystals, the control over the morphology, and insights into

Chiral anion recognition using calix[4]arene-based ureido receptors in a 1,3-alternate conformation

• Tereza Horáčková,
• Jan Budka,
• Vaclav Eigner,
• Wen-Sheng Chung,
• Petra Cuřínová and
• Pavel Lhoták

Beilstein J. Org. Chem. 2020, 16, 2999–3007, doi:10.3762/bjoc.16.249

• Tereza Horackova Jan Budka Vaclav Eigner Wen-Sheng Chung Petra Curinova Pavel Lhotak Department of Organic Chemistry, University of Chemistry and Technology, Prague (UCTP), Technicka 5, 166 28 Prague 6, Czech Republic Department of Solid State Chemistry, UCTP, 166 28 Prague 6, Czech Republic

• Å, respectively. Every ureido group held one molecule of DMSO via synchronous hydrogen bonding interactions between the two NH protons and a sulfoxide oxygen atom (Figure 3a). The S=O···H–N distances were 1.995, 2.285, 2.033, and 2.328 Å, indicating strong interactions in the solid state. At the

Naphthalonitriles featuring efficient emission in solution and in the solid state

• Sidharth Thulaseedharan Nair Sailaja,
• Iván Maisuls,
• Jutta Kösters,
• Alexander Hepp,
• Andreas Faust,
• Jens Voskuhl and
• Cristian A. Strassert

Beilstein J. Org. Chem. 2020, 16, 2960–2970, doi:10.3762/bjoc.16.246

• substitution and environment is reported with potential applications in sensing, bioimaging and optoelectronics. Keywords: aggregation caused quenching (ACQ); aggregation-induced emission enhancement (AIEE); naphthalonitriles (NCNs); solution and solid state emitters (SSSE); solvent quenching (SQ

• (AIE) [23][24][25][26][27]. They mentioned a series of silole derivatives with propeller-like conformations that show no emission in dilute solutions, but are highly luminescent when aggregated in the solid state. Their work has attracted major attention and quickly became one of the most sought-after

• materials equally efficient both in solution and in the solid state, thus bridging a gap between the dichotomous phenomena of ACQ and AIE with a new class of luminescent species, so-called dual-state emitting (DSE) compounds (DSEgens) [33]. While in many papers these compounds are called Dual State Emitting

Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

• Xinru Sheng,
• Errui Li and
• Feihe Huang

Beilstein J. Org. Chem. 2020, 16, 2954–2959, doi:10.3762/bjoc.16.245

• in the solid state. From single crystal X-ray diffraction, the linear guest molecules thread into cyclic pillar[4]arene[1]quinone host molecules in the solid state, stabilized by CH∙∙∙π interactions and hydrogen bonds. The bromine atoms at the periphery of the guest molecule provide convenience for

• reports [44][45]. We found that H and G can be used to build a [3]pseudorotaxane in the solid state but a [2]pseudorotaxane in solution. Results and Discussion Host–guest complexation in the solid state Cocrystals of H and G were obtained by slow evaporation of the solution in methanol. The X-ray

• crystallography revealed that two host molecules complex one guest molecule, forming a [3]pseudorotaxane in the solid state (Figure 1). In the crystal structure, the alkyl chain of the guest is threaded through the cavities of two host molecules, which is stabilized by multiple CH∙∙∙π interactions and hydrogen

Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity

• Yuvixza Lizarme-Salas,
• Alexandra Daryl Ariawan,
• Ranjala Ratnayake,
• Hendrik Luesch,
• Angela Finch and
• Luke Hunter

Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216

• (Figure 2), which was among the higher-energy calculated conformers of 2 (see Supporting Information File 1), bears a close resemblance to the solid-state conformation of piperine (1, Figure 1). The structure 2f has a F–C–C–F dihedral angle of 57° and a F–C–C=O dihedral angle of –133°. These angles

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• –property relationships showing the influence of the number and sequence of pyrrole rings. The highly planar π-conjugated systems revealed interesting structural features such as nearly complete bond length equalization and S–S and S–π dipolar interactions in the solid state. Due to tunable optoelectronic

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• of a reaction in the solid state. As such, we recently investigated the influence of the particle size of β-CD in the synthesis of β-CD mesitylene sulfonate (β-CDMts) in the solid state using a vibrating ball-mill. We were particularly interested in the role of the particle size on the kinetics of

• out in the presence of KOH as a base. The data series were confronted with kinetics models to get insight in the way the reactions proceeded. The diversity of possible models suggests that multiple mechanochemical processes can account for the formation of β-CDMts in the solid state. Throughout the

• , 7, and 8 α-ᴅ-glucopyranoside units, respectively. CDs are recognized as effective excipients in the formulation of numerous drugs [7][8][9][10]. Upon grinding, CDs form inclusion complexes with the drugs in the solid state, resulting in a significantly faster dissolution rate and increased

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• Information File 1). Slow diffusion of CH3CN into a concentrated solution of NDIC7 in CH2Cl2 yielded single crystals suitable for X-ray diffraction (Figure 2b). The macrocycle displays a folded conformation in the solid state due to the flexible linker, featuring an intramolecular NDI/naphthalene stacking

• is impeded. NDIC8 therefore does not fold but stacks with the naphthalene and NDI moieties of the neighbors alternatingly in the solid state and with a typical plane/plane distance of 3.57 Å [49]. Thermodynamic analysis of crown ether/ammonium complexes For the investigation of the thermodynamic

• intramolecular folding which was observed in the solid-state structure and is likely also present in solution, as indicated by a charge-transfer band. Nevertheless, it might be applicable for redox-controlled metal-sensing [60][61][62]. On the contrary, NDIC8 forms pseudo[2]rotaxanes and facilitates the

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• the solid state. It is shown that the inclusion of fullerenes into the water-soluble TBTQ-based host greatly compensates for their water-repulsive nature and results in the formation of self-assembled microspheres that may have some potential for biological and pharmaceutical applications. Results and

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• 1а with pinacol 2-phenylethynyl boronate. The meta-methoxystyryl derivative 5c was found to easily undergo photodimerization in solid state upon sunlight exposure, leading to the formation of compound 8 with a central cyclobutane ring (see Supporting Information File 1). As proved previously for