Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• -triazine derivatives. Molecular structures of compounds 12h (A) and 13c (B) representing both possible regioisomers of the alkylation reaction (displacement parameters are drawn at the 50% probability level). The X-ray data corroborate the obtained NMR data. Graphical overview about selected pyrazolo[1,2,3

Enantioselective PCCP Brønsted acid-catalyzed aminalization of aldehydes

• Martin Kamlar,
• Robert Reiberger,
• Martin Nigríni,
• Ivana Císařová and
• Jan Veselý

Beilstein J. Org. Chem. 2021, 17, 2433–2440, doi:10.3762/bjoc.17.160

• strategies employing chiral Brønsted acid catalysis. X-ray single-crystal structure of aminal 3l with the displacement ellipsoids drawn at the 30% probability level. The substrate scope of the aminalization reaction for different aldehydes. aAfter recrystallization; breaction run at 1 mmol scale. The

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• 2b. Displacement ellipsoids are drawn at the 50% probability level. Screening of the triazole derivatives of imatinib 1a,b, and 2a–j at concentrations of 1 μM and 10 μM against the human K562 cell line. Bars represent the mean ± standard deviation. The standard used was IMT. Interaction maps of IMT

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

• Suraj Patel,
• Tyson N. Dais,
• Paul G. Plieger and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

• –208 °C; Rf: 0.25 (30% EtOAc, 70% hexane). The common [2.2]cyclophanes. Crystal structure of 5. Ellipsoids are drawn at a 50% probability level [63][64][65][66]. Crystal structure of 6. Ellipsoids are drawn at a 50% probability level [63]. Crystal structure of 14. Ellipsoids are drawn at a 50

• % probability level [63]. Crystal structure of 15. Ellipsoids are drawn at a 50% probability level [63]. Possible origin of stereoselectivity. Nitration of [2.2]paracyclophane (1) and the synthesis of 4-hydroxy-5-nitro[2.2]metaparacyclophane (5) and the cyclohexadienone cyclophane 6 (average yield from more

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

• of 3-trifluoromethylpyrazole derivative 9d. The labeling scheme of the asymmetric unit is shown. Anisotropic displacement parameters of nonhydrogen atoms are drawn as ellipsoids with a 50% probability level. N atoms in blue, O atoms in red, C atoms in grey, H atoms as small white spheres. Structure

Free-radical cyclization approach to polyheterocycles containing pyrrole and pyridine rings

• Ivan P. Mosiagin,
• Olesya A. Tomashenko,
• Dar’ya V. Spiridonova,
• Mikhail S. Novikov,
• Sergey P. Tunik and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2021, 17, 1490–1498, doi:10.3762/bjoc.17.105

• parameters are drawn at 50% probability level. Molecular structure of compound 17a, displacement parameters are drawn at 50% probability level. Retrosynthetic analysis of heterocycles A and B. Free-radical cyclization of N-protected and N-unprotected pyrroles 1a and 2. Synthesis of 2H-pyrido[2,1-a]pyrrolo

Cascade intramolecular Prins/Friedel–Crafts cyclization for the synthesis of 4-aryltetralin-2-ols and 5-aryltetrahydro-5H-benzo[7]annulen-7-ols

• Jie Zheng,
• Shuyu Meng and
• Quanrui Wang

Beilstein J. Org. Chem. 2021, 17, 1481–1489, doi:10.3762/bjoc.17.104

• stereostructures of compound cis-14aa and trans-14aa. Crystal structure of the tosylate 21. The displacement ellipsoids are drawn at the 30% probability level. Reported strategies for the synthesis of tetralin-2-ol ring systems. Designed cascade reactions to 4-substituted tetralin-2-ols. The documented synthesis

Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• to the rapid thermal crystallization with a liquid guest alone, is not in conflict with the notion that co-crystallization suffers from processes that inhibit nucleation or crystal growth. Co-crystals are still expected to form slowly because of the low probability of molecules arriving at the

• have thus far evaded crystallization by themselves. Structure of TDA and TEO, the crystallization hosts used for co-crystallization. Details of the X-ray crystal structures obtained, shown as ORTEP plots at 50% probability, with van der Waals radii of the phenol molecules set to 60%. a) Asymmetric unit

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• introduces primary amines for 1,3-dipolar cycloaddition which is less explored due to the probability of competitive Strecker degradation over decarboxylation of azomethine ylides. The protocol reveals the efficiency of MW assisted reaction with reduced reaction time from 18 h to 12 min and enhanced the

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

• Mikhail K. Klychnikov,
• Radek Pohl,
• Ivana Císařová and
• Ullrich Jahn

Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58

• /EtOAc 10:1 to 1:1) to give keto lactam 13. Selected alkaloids containing the pyrrolidone motif. X-ray crystal structure of the major (2R,4S)-alkoxyamine hydrochloride derived from 9j. Displacement ellipsoids at 30% probability level and a disordered CHCl3 solvent molecule is not shown for clarity. X-ray

• crystal structure of the minor cis-diastereomers of the keto lactam 13j (left) and the hydroxy lactam 12k (right). Displacement ellipsoids are drawn at the 30% probability level. A) Classical γ-lactam synthesis by atom transfer radical cyclizations; B) previously developed tandem epoxide opening/Brook

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

• complex 17 with atom numbering scheme. The anisotropic displacement parameters are shown at the 50% probability level. Determination of relative cell viability (% of control) in different cell lines (HT-29; PC-3 and L-929) treated with compounds 6d (1), 6b (2), 5d (3), 5c (4), 5g (5), 5f (6) using the MTT

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• derivatives. Molecules of compounds 8a, 10, 11a, and the bistetrazolium cation 9, with displacement ellipsoids drawn at the 50% probability level. The hydrogen atoms are shown as spheres of arbitrary radii. The atom numbering is done for the asymmetric unit. Experimental (a) and TD-tHCTHhyb/6-311+G(2d,p

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• . subtilis. The fact that suppression effects are only observable for these genera could presumably be caused by the higher overlap in the ecological niches, triggering competition for the same nutrients. Indeed, a higher phylogenetic and metabolic similarity between bacteria increases the probability of

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

• applications or in the case of NMe2, as sensors of dielectric constants or water content. Molecular structure in the crystal of Me as obtained by X-ray diffractometric analysis. Thermal displacement ellipsoids are shown with 50% probability. Color code: black = carbon, grey = hydrogen and blue = nitrogen. A

Synthesis of purines and adenines containing the hexafluoroisopropyl group

• Viacheslav Petrov,
• Rebecca J. Dooley,
• Alexander A. Marchione,
• Elizabeth L. Diaz,
• Brittany S. Clem and
• William Marshall

Beilstein J. Org. Chem. 2020, 16, 2739–2748, doi:10.3762/bjoc.16.224

• drawn at 30% probability. Crystal structure of 7a, with the thermal ellipsoids drawn at 30% probability. Top: 19F NMR spectra of 3a acquired over a sample temperature range of 223–373 K. Left: Fitted plot of integrated intensity vs interpulse delay time from the experiment inverting the minor rotamer of

Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding

• Christopher B. Barnett,
• Tharindu Senapathi and
• Kevin J. Naidoo

Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206

• probability distribution gives the best indication of relevant regions. The fourth residue (Thr4) shows multimodal sampling in φ and a bimodal distribution in ψ, with conformers at (−100°, 0°) and (−60°, 130°) being preferred for the antigen (Figure 4E and F). However, when glycosylated the sampling of Thr is

• 3 of the peptide, aspartate, with a scatter plot showing the allowed φ–ψ regions highlighted in blue (A), and a probability density Ramachandran plot (B) for the antigen, and a scatter plot (C) and probability density Ramachandran plot (D) for the Tn-antigen. While the second row (E–H) illustrates

One-pot and metal-free synthesis of 3-arylated-4-nitrophenols via polyfunctionalized cyclohexanones from β-nitrostyrenes

• Haruyasu Asahara,
• Minami Hiraishi and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2020, 16, 1830–1836, doi:10.3762/bjoc.16.150

• afford nitrophenol 5b, which eluted with hexane/ethyl acetate 8:2 (41.7 mg, 0.17 mmol, 34%) as yellow solid. When the other nitroalkenes 1c–f were used, the reaction was conducted in the same way. X-ray crystallography of the major isomer of 4a. The thermal ellipsoids indicate 50% probability. Resonance

Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Valerii V. Tkachev,
• Andrey N. Utenyshev,
• Olga Yu. Karlutova,
• Alexander D. Dubonosov,
• Vladimir A. Bren,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2020, 16, 1820–1829, doi:10.3762/bjoc.16.149

• structure of 3Z. Thermal ellipsoids are drawn on the 30% probability level. Selected bond lengths (Å): C(3)–C(4) = 1.476(2), С(4)=С(5) = 1.360(2), С(3)=С(14) = 1.356(2). Molecular structure of 3E. Thermal ellipsoids are drawn on the 30% probability level. Selected bond lengths (Å): C(3)–C(4) = 1.461(2), С(4

• fulgide 3Z in acetonitrile solution before (1) and after irradiation with light of 436 nm for 30 (2), 60 (3) and 100 (4) s (2.5 × 10−5 M, T = 293 K). Molecular structure of photoproduct cis-9C’. Thermal ellipsoids are drawn on the 30% probability level. Selected bond lengths (Å): С(5)–С(16) = 1.531(3), С

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

• h, 91%; h) 1) DPPA, DBU, PhMe, 25 °C, 15 h; 2) NaN3, PhMe, 60 °C, 4 h, 87%; i) 1) MeOTf, CH2Cl2, 25 °C, 2.5 h; 2) NaBH4, THF/MeOH 4:1 v/v, 0 °C, 2.5 h; 3) oxalic acid, THF/H2O 4:1 v/v, 25 °C, 20 h, 86%. Overall yield to 5: 45% (8 steps). The molecular structure of 5 shows 50% probability ellipsoids

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

• probability of charge recombinations [89]. Serpone et al. found that 85% of the photogeneration events resulted in a recombination after 10 ns of illuminating TiO2 particles [90]. This implies that higher irradiation intensity may hinder photocatalysis by increasing the charge carrier density and subsequently

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• . Selected examples of triazinethione-containing bioactive compounds. X-ray structure of 6-(methylthio)-4-phenyl-3,4-dihydro-1,3,5-triazine-2(1H)-thione (6aa) with thermal ellipsoids at 50% probability (CCDC 1991859). Strategies for the synthesis of triazinethiones. Aldehyde substrate scope of three

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• natural pyrrolizine- and isoindole-containing alkaloids. Structures of 9m (a) and 10m (b) as determined by single-crystal X-ray diffraction crystallography (ellipsoids at the 30% probability level). M06-2X/6-31+G(d,p) Optimized geometry for each of the SCs (a and d), TSs (b and e) and ADs (c and f) of the

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

• molecular structures of cis-9c and trans-9d drawn using 50% probability displacement ellipsoids. The terminology cis and trans referred to the relative orientation of Ph and Fc groups. Synthesis of spirotetrahydrothiophenes 3 via non-concerted [3 + 2]-cycloadditions of thiocarbonyl ylide 1 with electron

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• ) database, which compares the molecular structure of test compounds vs a large training set of experimental bioactive or inactive compounds [21]. The results of the prediction are summarized as probability of activity (Pa) and probability of inactivity (Pi) values, both ranging from 0 to 1 (Figure 2), where