Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• recrystallization. The molecular structure of 2, determined through single-crystal X-ray diffraction analysis, is illustrated in Figure 2, and selected geometrical parameters are shown in Table 1. The results revealed that the naphthalene and fused phosphole rings are almost coplanar (mean deviation = 0.030 Å). The

Deoxygenative C2-heteroarylation of quinoline N-oxides: facile access to α-triazolylquinolines

• Geetanjali S. Sontakke,
• Rahul K. Shukla and
• Chandra M. R. Volla

Beilstein J. Org. Chem. 2021, 17, 485–493, doi:10.3762/bjoc.17.42

• ). Electronically rich Me and OMe groups at the 4- or 6-positions of N-oxides were tolerated and delivered the corresponding C2-triazolylquinolines 3z, 3aa and 3ab in 85–90% yield. Further, the structure was unambiguously confirmed by the single-crystal X-ray diffraction analysis of 3z [63]. Halogenated substrates

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• -detection (see Supporting Information File 1, Figures S38–S40). X-ray molecular structures The structures of the title compounds 10a–c were further explored by a single-crystal X-ray diffraction analysis (Figure 1, see also Supporting Information File 1, Figures S35–S37 and Table S1) and compared with that

• steps of the method are electrophile-induced 6-endo-dig cyclizations of ortho-alkynylated biaryls. The overall yields of helicenes in five stages of the synthesis exceed 30%. The single-crystal X-ray diffraction analysis revealed the non-planar crystal structures of the synthesized helicenes responsible

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

• maximum. This also indicated that the interactions between H and G were weak. Conclusion In summary, we constructed novel pseudorotaxanes based on a pillar[4]arene[1]quinone and 1,10-dibromodecane. Single crystal X-ray diffraction analysis showed an alkane molecule threaded into the cavities of two pillar

Ultrasound-assisted Strecker synthesis of novel 2-(hetero)aryl-2-(arylamino)acetonitrile derivatives

• Emese Gal,
• Luiza Gaina,
• Hermina Petkes,
• Alexandra Pop,
• Castelia Cristea,
• Gabriel Barta,
• Dan Cristian Vodnar and
• Luminiţa Silaghi-Dumitrescu

Beilstein J. Org. Chem. 2020, 16, 2929–2936, doi:10.3762/bjoc.16.242

• precipitated from the reaction mixture in crystalline form as depicted by scanning electron microscopy (SEM) analysis. The single crystal X-ray diffraction analysis disclosed the arrangement of the α-(arylamino)acetonitrile molecules in the aggregated crystalline state as a racemic mixture. The mutagenic

Synthesis and investigation of quadruplex-DNA-binding, 9-O-substituted berberine derivatives

• Jonas Becher,
• Daria V. Berdnikova,
• Heiko Ihmels and
• Christopher Stremmel

Beilstein J. Org. Chem. 2020, 16, 2795–2806, doi:10.3762/bjoc.16.230

• particular binding mode. However, it was shown by X-ray diffraction analysis of the G4-DNA-bound ligand 1e3 that the berberine unit binds to quadruplex DNA by π-stacking with the 3’-end quartet in a similar mode as the parent berberine; however, in the case of 1e3 the aryl-substituents of the side chain are

Selective and reversible 1,3-dipolar cycloaddition of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones under microwave irradiation

• Alexander P. Molchanov,
• Mariia M. Efremova,
• Mariya A. Kryukova and
• Mikhail A. Kuznetsov

Beilstein J. Org. Chem. 2020, 16, 2679–2686, doi:10.3762/bjoc.16.218

• ). Accordingly, two characteristic signals for carbon atoms of the pyrazolidine ring are present in the 13C NMR spectrum – at 72.2 (2СН) and 68.7 (СН) ppm. The spatial configuration of the adducts 3e and 3g was further determined by single crystal X-ray diffraction analysis (Figure 1 and Figure 2). All products

Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K₂S₂O₈

• Qiang Liu,
• Weibang Lu,
• Guanqun Xie and
• Xiaoxia Wang

Beilstein J. Org. Chem. 2020, 16, 1974–1982, doi:10.3762/bjoc.16.164

• (Table 1, entry 1). The structure of 3aa was unambiguously confirmed by X-ray diffraction analysis of a single crystal (Figure 2) and by NMR spectroscopy (see Supporting Information File 1) [33]. The increase of the amount of K2S2O8 to 3 equiv resulted in the improvement of the yield of 3aa to 52% (Table

Synthesis of 3(2)-phosphonylated thiazolo[3,2-a]oxopyrimidines

• Ksenia I. Kaskevich,
• Anastasia A. Babushkina,
• Vladislav V. Gurzhiy,
• Dmitrij M. Egorov,
• Nataly I. Svintsitskaya and
• Albina V. Dogadina

Beilstein J. Org. Chem. 2020, 16, 1947–1954, doi:10.3762/bjoc.16.161

• thiazolopyrimidine-5-ones by reacting 6-methyl-2-thiouracils with bromoethynylketones has been reported by Shishkin and co-workers (Scheme 4) [20]. The authors for the first time proved the structure of the 5-oxo isomer by single crystal X-ray diffraction analysis. The Pd-catalyzed Sonogashira coupling reaction

• ., doublets at 119.78 (1JHP = 209.5 Hz) and 130.24 ppm (1JHP = 217.5 Hz). The remaining signals were completely identical. Finally, the X-ray diffraction analysis of the 2-phosphonylated thiazolopyrimidine 9c allowed us to uniquely determine its structure. In our opinion, the unusual formation of the 2

• NMR spectroscopy. In the 13C NMR spectra of the thiazolopyrimidines 6a–c, the O=C–CH=CH fragment is observed by signals of equal intensity at δC 112–113 and 135–136 ppm. However, the unambiguous proof of the structure of thiazolopyrimidine-7-one 6b was obtained by single crystal X-ray diffraction

Selective preparation of tetrasubstituted fluoroalkenes by fluorine-directed oxetane ring-opening reactions

• Clément Q. Fontenelle,
• Thibault Thierry,
• Romain Laporte,
• Emmanuel Pfund and
• Thierry Lequeux

Beilstein J. Org. Chem. 2020, 16, 1936–1946, doi:10.3762/bjoc.16.160

• major isomer were obtained by recrystallization. The X-ray diffraction analysis clearly showed that the bromine atom was located on the carbon trans to the fluorine atom resulting in the major product with the E-geometry (see Supporting Information File 1). It should be noted that longer reaction times

• ]. Pleasingly, when subjecting compound 4 to the previous reaction conditions, a single isomer of bromoalcohol 4d formed (determined by 1H NMR of the crude) and the product was isolated in an excellent yield of 94% (Table 2, entry 3). The geometry of the product was confirmed to be E-4d by X-ray diffraction

• analysis (see Supporting Information File 1). The attack of the bromide ion this time occurred from the side of the alkene hydrogen atom (cis attack) and away from the bulky phthalimido group giving solely product E-4d. Likewise, the reaction of the alkyl-substituted substrate 5 proceeded with excellent E

On the hydrolysis of diethyl 2-(perfluorophenyl)malonate

• Ilya V. Taydakov and
• Mikhail A. Kiskin

Beilstein J. Org. Chem. 2020, 16, 1863–1868, doi:10.3762/bjoc.16.153

• Supporting Information File 148: Detailed information about experimental procedures, X-ray diffraction experiments for compound 12 and characterization data for compounds 3 and 12. Acknowledgements Single crystal X-ray diffraction analysis was performed using the equipment at the Centre for Collective Use

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

• were formed with complete diastereoselectivity, leading to a single isomer. In order to establish the structure of the isomers, a single crystal obtained for compound 9c was studied by X-ray diffraction analysis which showed, that the Ph(C-2) group and Fc(C-5) substituent were mutually cis-oriented

• 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

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

• structure as depicted in Scheme 1. A crystal of the compound was grown by diffusion of water into a solution of F-1 in DMSO. The results of the X-ray diffraction analysis are shown in Figure 1. The single crystal material of F-1 (F-1a phase) was in the monoclinic space group P21/c, with the lattice

• immediately after vacuum drying suggested that some structural parameters, such as the water content, varied in the two analyses. The final proof that the phase change was due to some water molecules escaping the crystal, and this proof came from the X-ray diffraction analysis of heated crystals of F-1 (with

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• resulting copper complexes were synthesized and single crystal X-ray diffraction analysis evidenced the existence of H-bonding inside the coordination sphere of 6 (Scheme 3). The authors reported that the influence of the geometry of the complex on the H-bonding interactions as well as the nature of this

• . Strikingly, combination of these unique steric and electronic features results in a distorted pentacoordinated sphere exhibiting a newly occupied coordination site, as confirmed by single crystal X-ray diffraction analysis. This particular geometry results in enhanced catalytic reactivity and is clearly

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

• -diphenylpyrene is the key step. The single crystal X-ray diffraction analysis revealed a twisted structure of 1 due to the steric hindrance at the bay positions. From the bond length analysis and DFT calculations, CP-PAH 1 consists of the aromatic peropyrene core with two slightly antiaromatic peri-fused five

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

• . Supporting Information File 12: CIF file of 14c. Acknowledgements Marcin Kaźmierczak and Henryk Koroniak would like to thank Prof. Maciej Kubicki for X-ray diffraction analysis. Funding Marcin Kaźmierczak would like to thank the National Science Centre for financial support under grant 2018/02/X/ST5/02867

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

• direct borylation of C–H bonds in terrylene in 56% yield. The product is soluble in common organic solvents and could be purified without column chromatography. Single crystal X-ray diffraction analysis revealed that the terrylene core is not disturbed by the substituents and is perfectly flat. The

• 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

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

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

• and 4c were likely to assist the formation of well-ordered aggregates, being consistent with the observation of the red-shifted luminescence discussed above. Crystal structures of 4b and 4c The molecular structures of 4b and 4c were unambiguously determined by single crystal X-ray diffraction analysis

• -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

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• several copolymers showed a superior solubility. X-ray diffraction analysis of the thin film of the alternating copolymers composed of methyl and branched oligosiloxane substituents was also performed, and the results suggested the formation of a dual-layered film structure. Keywords: alternating

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

• 2D NMR experiments), and X-ray diffraction analysis. The signals in the 1H and 13C NMR spectra of some of the compounds 4 were duplicated. This could have been caused by two reasons, namely by free rotation of the azolyl fragment in the position 7 or by the presence of a second diastereomer. To

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

• methoxy-substituted styrylquinolizinium derivatives form the corresponding syn head-to-tail cyclobutanes in a selective [2 + 2] photocycloaddition, as revealed by X-ray diffraction analysis of the reaction products. These photodimers bind to DNA only weakly by outside-edge association, but they release

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

• via removing the iodide anion by AgOAc and CF3COOAg. A single crystal of 2-OAc suitable for X-ray diffraction analysis was obtained by slow diffusion of n-pentane into a dichloromethane solution. A single crystal of 2-TFA suitable for X-ray diffraction analysis was obtained by slow evaporation of

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

• 7), and three acylated drimanes, nanangenines F–H (8–10), which are putative biosynthetic intermediates. The structures of 1–10 were elucidated by detailed spectroscopic analysis, while absolute configurations were determined by single crystal X-ray diffraction analysis of selected analogues. High

• strobilactone B, previously reported from A. ustus [29], with the only difference being hydroxylation at C-1 in 1, instead of at C-2. Therefore, the structure of 1 was assigned as shown in Figure 1. The absolute configuration of 1 was confirmed to be 1R,5S,6R,9R,13R by single crystal X-ray diffraction analysis

• reported in 2014 as an unnamed metabolite from Aspergillus sp. IBWF002-96 [5], and we have assigned the trivial name nanangenine B for consistency. The absolute configuration of 2 was assigned based on single crystal X-ray diffraction analysis of a 9-O-(4-bromobenzoyl) derivative (2b; Table S2 and Figure

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

• vinylogues of recently reported acylphosphonium zwitterions [25]. Structural studies The solid-state molecular structures of betaines E-3a, E-3b, E-3e and Z-3e were determined by single-crystal X-ray diffraction analysis and are shown in Figures 2–5. Some data characterizing the bonding geometry of the P+–C1