Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• comprising of electron-donating and accepting groups in a donor–π–acceptor (D–π–A) system. The dyes exhibit strong absorption and emission properties in solution and in the solid state [1][2][3]. One important feature of these molecules is an exceptional polarizability which is a crucial criterion for NLO

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• reactions, and even in nanomaterials preparation [1][2][3][4][5]. Indeed, solid-state mechanochemical methodologies are a viable alternative to traditional syntheses in solution [4] for the preparation of complex molecules, either under solvent-free conditions, named ‘neat grinding’, or in nearly solvent

• ), by following a straightforward synthetic strategy recently reported by some of us [26]. Then, in order to assess the efficacy of the solid-state milling approach in the formation of boronate esters between the PBA moiety of 1 and the vicinal diols of dextran (Dex), both mechanochemical and

Synthesis of 6,13-difluoropentacene

• Matthias W. Tripp and
• Ulrich Koert

Beilstein J. Org. Chem. 2020, 16, 2136–2140, doi:10.3762/bjoc.16.181

• derivatization of known compounds [4]. Since the performance of these devices is strongly dependent on the optoelectronic solid-state properties of the pentacenes, predictable control of the electronic structure is desirable. A common strategy to influence the electronic properties of pentacenes, without

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

• Ian Walsh,
• Matthew S. F. Choo,
• Sim Lyn Chiin,
• Amelia Mak,
• Shi Jie Tay,
• Pauline M. Rudd,
• Yang Yuansheng,
• Andre Choo,
• Ho Ying Swan and
• Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

• Capillary electrophoresis of the released and APTS-labelled antibody N-glycans was performed on a CESI8000 CE instrument (Sciex) equipped with a solid state laser-induced fluorescent detector (excitation 488 nm, emission 520 nm). Separations were made across a 20 cm effective length (30 cm total length), 50

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

• Thomas Schneider,
• Michael Keim,
• Bianca Seitz and
• Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

• -(dimethylamino)indenes as the major products. Various other synthetic applications of these reactive propyn-1-iminium salts will be reported in due course. Solid-state molecular structure of 11 (ORTEP plot). Solid-state molecular structure of 12c (ORTEP plot). Solid-state molecular structure of 12d (ORTEP plot

• . Synthesis and solid-state molecular structure (ORTEP plot) of pentafulvene 19; selected bond distances (Å), see molecule plot for atom numbering: C8‒C7 1.370(2), C7‒C17 1.481(2), C17‒C18 1.343(2), C18‒C5 1.471(2), C5‒C6 1.374(2), C6‒C7 1.496(2). Proposed mechanistic pathway leading to fulvene 19

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and ⁶Li/¹³C NMR spectroscopic data

• Jürgen Vollhardt,
• Hans Jörg Lindner and
• Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

• . Their anion is stabilized by electrostatic interaction, polarization, and negative nC-σ*SR hyperconjugation, with electrostatic interaction as dominating mechanism [56][58]. The lithio methanides 1 are monomeric or dimeric in THF solution and the solid state, depending on Lewis basic ligands of the

• atoms and not between orbitals. A similar conclusion was reached in the case of the dilithio methandiides IIIa and IIIb. Conclusion The determination of the structure of tetramer 2a-I in both the solution and solid state, which is the first of a dilithio methandiide, was achieved based on X-ray crystal

Controlling the stereochemistry in 2-oxo-aldehyde-derived Ugi adducts through the cinchona alkaloid-promoted electrophilic fluorination

• Yuqing Wang,
• Gaigai Wang,
• Anatoly A. Peshkov,
• Ruwei Yao,
• Muhammad Hasan,
• Manzoor Zaman,
• Chao Liu,
• Stepan Kashtanov,
• Olga P. Pereshivko and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2020, 16, 1963–1973, doi:10.3762/bjoc.16.163

• -triggered complexation with boron trifluoride diethyl etherate. The resulting O,O-chelated boron complexes 11 turned out to be strong solid-state emitters featuring clear aggregation-induced emission (AIE) characteristics [61]. Encouraged by these results, we decided to attempt the reaction of 2-oxo

Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization

• Dominik Göbel,
• Marius Friedrich,
• Enno Lork and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2020, 16, 1683–1692, doi:10.3762/bjoc.16.139

• Figure 2a and Figures S1–S11 in Supporting Information File 1). The emission spectra for para-bromocarbaldehyde 3 and adamantyltriazole 34 in the solid-state show maxima at 440 nm (for compound 3) and 416 nm (for compound 34) (see Figure 2b). Additionally, fluorescence lifetimes (τ) of 3 and 34 were

• determined by time correlated single photon counting (TCSPC), indicating low lifetimes of 2.21 ns (for compound 3) and 3.23 ns (for compound 34) for lower populated species (see Figure S6, Supporting Information File 1). Quantum yields (Φ) of both derivatives are below 1% in the solid-state. In chloroform

• , no luminescence was detected for the para derivatives. All ortho derivatives exhibited luminescence neither in solution nor in the solid-state [73]. These observations for the para- and ortho-bromobenzaldehydes indicate that the phosphorescence is quenched in these systems, yielding only a weak

Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• established by single crystal X-ray diffraction (Figure 2). Interestingly, a study by Pattison has established that α-fluoroketones preferentially adopt a cis-conformation in polar solvents [54]. In the solid state, a dihedral angle of φ = −3.7° was observed thereby placing the C–F bond in the same plane as

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

• was E1/2 = +0.380 V vs SCE showing that rotaxane 1a retained the redox properties of the parent ferrocene [21][22]. Importantly, the full reversibility of the one electron oxidation–reduction process attested to the stability of the electroactive system. Solid-state X-ray structure The solid-state

• 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

• structures of (a) rotaxane 1a and (b) Leigh’s rotaxane I [4]. Selected H···O distances from the solid-state structures. Supporting Information Supporting Information File 71: Further experimental details and NMR spectra of new compounds. Supporting Information File 72: X-ray data of rotaxane 1a

Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• modifications of starch using ball milling have been reported. These included esterifications and etherifications of starch [19] and cellulose [20]. In 2017, Jicsinszky et al. obtained CD derivatives through a solid-state reaction, using a planetary ball mill [21][22] and by other green processes [23]. The main

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

• recommend exploring the article for further details [95]. Molecules with functional groups such as carboxylic acid present complex surface topologies from bridging and bidentate binding modes [91]. Yoshida and co-workers studied the adsorption of benzene derivatives on TiO2 surfaces by solid-state NMR and

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• light ray and the structures often include fluorescein, rhodamine, or 7-amino-4-methylcoumarin (7-AMC) scaffolds as fluorophores. These fluorophores usually exhibit strong fluorescence in dilute solutions, but most of their emissions are partially or completely quenched in the solid state or in highly

• concentrated solutions by aggregation-caused quenching (ACQ) [8]. On the other hand, there are molecules that exhibit strong emission even in poor solvents or in the solid state. This property is referred to as aggregation-induced emission (AIE) and has attracted much attention in the field of fluorescence

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

• 355a afforded the desired product 356a in 70% yield with 40% ee at −45 °C and 75% yield with 10% ee at 0 °C, respectively, in the solid state [98] (Scheme 73). Compared with cyclic thioetherification reactions, the photochemical cycloadditions of thiocarbonyl compounds and olefins are highly suitable

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

• ) which is usually detected for materials exhibiting low-intensity emissions [22][23]. Exciplex-forming properties Since compound 1 was characterized by the most blue-shifted fluorescence in the solid-state and a high first triplet energy level of 2.97 eV (Figure 5a and Figure 7a), this compound was

• regarded as a promising candidate for blue exciplex formation in the solid state. Indeed, compound 1 formed a sky-blue emitting exciplex (501 nm) in a solid mixture with the acceptor 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T). Moreover, an orange exciplex emission with a PL spectrum

• , CDCl3) δ 8.28–8.22 (m, 2H), 8.16 (d, J = 9.1 Hz, 2H), 7.96–7.84 (m, 3H), 7.61 (dd, J = 9.5, 6.6 Hz, 4H), 6.94 (tt, J = 8.6, 2.4 Hz, 1H); 13C NMR (101 MHz, CDCl3) δ 165.01, 161.01, 156.01, 149.40, 134.00, 133.90, 133.10, 129.24, 128.8, 128.66, 127.76, 127.4, 127.14, 104.70; ATR-IR (solid state on ATR, cm

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

• ][21]. Another drawback of these reactions is the selectivity, because good selectivity is achieved in photocycloadditions in solid state provided that the topochemical Schmidt's conditions are met [22][23][24], but the selectivity in solution is usually not as high [25][26]. Our group is interested in

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

• from the acridan unit. Slightly higher IPPES values were obtained by PES measurements for compounds 3–6 in comparison to those estimated by CV and can apparently be explained by a more difficult removal of electrons from materials in the solid state than in solution due to the strong intermolecular

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

• Laura Sršan and
• Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

• for Solid State Research for help in the field of ES-IBD. We also thank http://www.pixabay.com for providing parts of our graphical abstract. Funding We would like to thank the Baden-Württemberg Stiftung for financial support.

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

• the tight packing observed for the homo π-stacking. Similarly, a mixture between the homo and hetero π-stacking would cause a more amorphous crystal and would be the least likely to form in a solid state a crystal suitable for determination by X-ray diffraction. The driving force for this crystal

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

• revealed there nature in the solid state to form a 1-dimensional columnar structure stabilised by π–π and/or CH∙∙∙π interactions with full or partial overlap of the molecular skeleton as seen in the crystal structure of 1, however, each packing fashion is different depending on the substituent. UV–vis and

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• of TIPS-ethynyl-substituted BODIPY derivatives 3–6 were characterized by 1H and 19F NMR spectroscopy, high-resolution mass spectrometry, and X-ray crystallographic analysis. The solid-state structures of the diethynyl-substituted BODIPYs were unambiguously elucidated by X-ray diffraction analysis (3a

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• ), respectively (Scheme 1). The catalysts were characterized by a series of analytical techniques. The solid-state 13C NMR of IPSi showed nine peaks at 10, 24, 43, 63, 121, 136, 148, 155, and 162 ppm, respectively. SEM analysis displayed an irregular shape for 1a and 1b. The catalytic activity of Cu(I)@IPSi (1a

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

• characteristics in the solid state. The crystal structures of the coupling products were also evaluated by single crystal X-ray analysis and the well-ordered intermolecular stacking arrangements appeared to be responsible for the enhanced CPL. Keywords: BINOL; C–H activation; circularly polarized luminescence

• an interesting aggregation-induced enhancement of CPL in the solid state with considerably higher dissymmetry factors compared to those in solution. Results and Discussion Synthesis of BINOL-derived BBFPys The study was initiated with the synthesis of 2,6-diaryloxypyridines 3 bearing a 1,1

• 0.37–0.40. The emission bands of 4a–c in their solid state were considerably red-shifted as compared to that of 6, suggesting that these compounds displayed the appreciable effect of molecular aggregation. Interestingly, 4b and 4c, bearing the additional terminal tert-butyl substituents, were more red

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

• containing isoxazoline rings 17a–c and isoxazoles 18a–c, as well as LCs amides 19–22 and 24. All compounds listed in Table 1 are capable of self-organization by hydrogen bonds, either in their solid state or in solution. Solubility in protic or aprotic polar solvent is restricted at room temperature. However

• DSC graphs. This finding is detailed on the DSC graph for compounds 17a, 19 and 20 (see Figure 3). The thermal changes in DSC may be interpreted by intermolecular hydrogen bonds, which can be established between thiourea molecules in their solid state or in the liquid crystal mesophases. Liquid

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

• -carboxylic acid was anchored to Wang resin and then subjected to the conditions for the alkenylation reaction with 2a using the solid catalyst (3 mg) for 48 h. After that, the reaction mixture was worked up, and the solid product was isolated and subjected to solid-state NMR spectroscopy. The results were