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

• drawn at the 50% probability level. Variable temperature χT product (blue) and χ (green) of 8 (top) and 9 (bottom) measured at an external magnetic field of 1 T in the heating mode (see Supporting Information File 1 for fitting parameters). Synthesis of photochromic ligands. Reversible photocyclization

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

• % probability level. Three synthetic approaches to dihydrotetrazolo[1,5-a]pyrimidines. Three-component reaction of 1, 7a,b and 8a–d in water. Three-component reaction of 5-aminotetrazole (1) with formaldehyde (7a) and acetylacetone (10). a) Three-component reaction of 5-aminotetrazole (1) with acetaldehyde (7b

An overview of the cycloaddition chemistry of fulvenes and emerging applications

• Ellen Swan,
• Kirsten Platts and
• Anton Blencowe

Beilstein J. Org. Chem. 2019, 15, 2113–2132, doi:10.3762/bjoc.15.209

• reactive, is prone to dimerization and polymerisation [59][111]. If the reaction is conducted under aqueous conditions, the probability of dimerization has been reported to increase further due to hydrophobic packing of the fulvene molecules [120][121]. Intramolecular cycloadditions Whilst not as widely

Characterization of two new degradation products of atorvastatin calcium formed upon treatment with strong acids

• Jürgen Krauß,
• Monika Klimt,
• Markus Luber,
• Peter Mayer and
• Franz Bracher

Beilstein J. Org. Chem. 2019, 15, 2085–2091, doi:10.3762/bjoc.15.206

• probability level. Bottom: Molecular structure of artefact 7 (drawn at the 50% ellipsoid probability level). Separation of atorvastatin (1; retention time: 5.8 min) from the four decomposition products 2 (retention time: 9.2 min), 3 (retention time: 15.6 min), 6 (retention time: 21.4 min) and 7 (retention

Synthesis of benzo[d]imidazo[2,1-b]benzoselenoazoles: Cs₂CO₃-mediated cyclization of 1-(2-bromoaryl)benzimidazoles with selenium

• Mio Matsumura,
• Yuki Kitamura,
• Arisa Yamauchi,
• Yoshitaka Kanazawa,
• Yuki Murata,
• Tadashi Hyodo,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2019, 15, 2029–2035, doi:10.3762/bjoc.15.199

• residue was purified by silica gel chromatography (n-hexane/AcOEt). (a) Ortep drawing of 2a (50% probability, only one of two independent molecules is shown) and (b) packing structure. The component based solvent was omitted for clarity. Cs2CO3-mediated cyclization of 1-(2-bromoaryl)imidazoles with Se

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• devices sensitized with BOD-TTPA-alk are slightly higher compared to the ones prepared out of BOD-TTPA. This could be explained by the presence of the alkyl chains on the TPA units that are known to prevent the redox mediator to interact with the TiO2 surface thus reducing the probability to observe a

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• aliphatic alkynes gave an optimal yield of the final product in the range of 50–78%. Successful formation of the product on application of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO: a radical scavenger) has nullified the probability of radical pathway. It was thought to be initiated by the coordination of

Transient and intermediate carbocations in ruthenium tetroxide oxidation of saturated rings

• Manuel Pedrón,
• Laura Legnani,
• Maria-Assunta Chiacchio,
• Pierluigi Caramella,
• Tomás Tejero and
• Pedro Merino

Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158

• attractors [74], that are the areas in which the probability of finding an electron pair is maximal. Monosynaptic and disynaptic basins correspond to separate atoms and bonds, respectively. When a bond is formed, two monosynaptic basins merge into a new disynaptic basin. The complete ELF analyses of the IRCs

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• ) and antibacterial activity (center and right). ORTEP plot of 5-benzoyl-3-phenyl-1H-pyrazole (6a) (thermal ellipsoids at 30% probability); the direction of intermolecular N−H···O hydrogen bonding is indicated by dashed lines. Ellipsoid plot of 1-Boc-5-benzoyl-5-hydroxypyrazoline 5a. ORTEP plot and

• dimer of compound 5r (thermal ellipsoids at 30% probability). Glyoxylation–alkynylation (GA) and activation–alkynylation (AA) synthesis of alkynediones in a one-pot fashion. Consecutive three-component synthesis to give 5-benzoyl-3-phenyl-1H-pyrazole (6a) after alkaline deacylation of intermediate 5a

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

• Andrew T. King,
• Hugh G. Hiscocks,
• Lidia Matesic,
• Mohan Bhadbhade,
• Roger Bishop and
• Alison T. Ung

Beilstein J. Org. Chem. 2019, 15, 1347–1354, doi:10.3762/bjoc.15.134

• . Possible compounds with the molecular formula C33H26N2O (structure 7 contains 27 hydrogen atoms). ORTEP view of the molecule 8 showing the atom labelling (ellipsoids are drawn at 50% probability level). Significant intermolecular interactions made by the benzhydryl group (a, upper) and the gem-diphenyl

Doebner-type pyrazolopyridine carboxylic acids in an Ugi four-component reaction

• Maryna V. Murlykina,
• Oleksandr V. Kolomiets,
• Maryna M. Kornet,
• Yana I. Sakhno,
• Sergey M. Desenko,
• Victoriya V. Dyakonenko,
• Svetlana V. Shishkina,
• Oleksandr A. Brazhko,
• Vladimir I. Musatov,
• Alexander V. Tsygankov,
• Erik V. Van der Eycken and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2019, 15, 1281–1288, doi:10.3762/bjoc.15.126

• -(4-chlorophenyl)-2-oxoethyl)-6-(4-methoxyphenyl)-3-methyl-N-p-tolyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide (11n) according to X-ray diffraction data. Non-hydrogen atoms are presented as thermal ellipsoids with 50% probability. An overview of heterocyclic acids used in the Ugi reaction. Synthesis of

Understanding the unexpected effect of frequency on the kinetics of a covalent reaction under ball-milling conditions

• Ana M. Belenguer,
• Adam A. L. Michalchuk,
• Giulio I. Lampronti and
• Jeremy K. M. Sanders

Beilstein J. Org. Chem. 2019, 15, 1226–1235, doi:10.3762/bjoc.15.120

• the temperature term of the traditional Arrhenius equation can be (to a first approximation) replaced by the rate of supply of mechanical energy, W [29], (Equation 2) Hence, k2 represents the ‘per impact’ probability of reaction. We note that the individual terms of Equation 2 are indeed expected to

• ) can dominate subsequent stages of the transformation, as the probability of contact formation decreases. While further work is required to capture detailed mechanistic insight, we can suggest that kinetic modelling of covalent mechanochemical reactions likely requires a model that accounts for both

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• peroxide, DTBP) led to increased amounts of insoluble polymer. Molecular structure of 6a (displacement parameters are drawn at 50% probability level), distance C1–C3 1.844(3) Å. NMR spectra of pure 6a (green) and 6d (red) and the obtained mixture with the new compound 15 (blue). Summary of the most recent

• structure of 14 could be proven by single-crystal X-ray diffraction (displacement parameters are drawn at 50% probability level). Reaction of propellane (1) with the two disulfides 10a and 10d. When two different disulfides were used, all three possible products were obtained. The yields were determined by

• by single-crystal X-ray diffraction (displacement parameters are drawn at 50% probability level). Results of the insertion of 1 into aromatic disulfide bonds. The ratio of 1:10 determines the amount of [2]staffane formed. Supporting Information Full experimental details and analytical data (1H NMR

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• Heck cyclization reaction between the substituted alkyne and aryl bromide in 133 takes place to form a cyclic palladium intermediate 134 with E-configuration, resulting from a syn-addition mechanism of this step. The addition of a silver salt reduces the probability of isomerization of the double bond

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• structure of 1-([1,1'-biphenyl]-4-yl)-5-oxo-7-phenyl-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-3-aminium 2,2,2-trifluoroacetate 9i according to X-ray diffraction data. Thermal ellipsoids of atoms are shown at 50% probability level. Molecular structure of 3-(2-amino-4-phenyl-1H-imidazol-5-yl)-3-(p-tolyl

• )propanoic acid 11b according to X-ray diffraction data. Thermal ellipsoids of atoms are shown at 50% probability level. Molecular structure of aminoimidazo[1,2-c]pyrrole 16a according to X-ray diffraction data. Thermal ellipsoids of atoms are shown at 50% probability level. 3,3’-Spirooxindole alkaloids

• . Molecular structure of aminoimidazo[1,2-c]pyrrole 19a according to X-ray diffraction data. Thermal ellipsoids of atoms are shown at 50% probability level. The three component condensation of imidazo[1,2-a]pyridine, aldehydes and Meldrum’s acid described by Gerencsér at al. [31]. Two forms of cation 9i

An anomalous addition of chlorosulfonyl isocyanate to a carbonyl group: the synthesis of ((3aS,7aR,E)-2-ethyl-3-oxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-1-ylidene)sulfamoyl chloride

• Aytekin Köse,
• Aslı Ünal,
• Ertan Şahin,
• Uğur Bozkaya and
• Yunus Kara

Beilstein J. Org. Chem. 2019, 15, 931–936, doi:10.3762/bjoc.15.89

• for C10H13ClN2O3S, 276.7350; found, 277.0434. The dipolar intermediate formed in the reaction of CSI with olefins. (a) Molecular structure of racemic molecule 10 (asymmetric unit). Thermal ellipsoids are drawn at the 30% probability level. (b) Geometric parameter with H-bonded geometry. Hydrogen bonds

Efficient synthesis of pyrazolopyridines containing a chromane backbone through domino reaction

• Razieh Navari,
• Saeed Balalaie,
• Saber Mehrparvar,
• Fatemeh Darvish,
• Frank Rominger,
• Fatima Hamdan and
• Sattar Mirzaie

Beilstein J. Org. Chem. 2019, 15, 874–880, doi:10.3762/bjoc.15.85

• molecules based on the pyrazolopyridine framework. ORTEP Structure of compound 4a and intermolecular hydrogen bonding; the ellipsoid probability level of each ORTEP diagram is 50%. Structures of synthesized pyrazolopyridines 4a–m. Reaction conditions: 3-formylchromone derivatives (1 mmol), primary amine

Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

• Ayato Yamada,
• Manabu Abe,
• Yoshinobu Nishimura,
• Shoji Ishizaka,
• Masashi Namba,
• Taku Nakashima,
• Kiyofumi Shimoji and
• Noboru Hattori

Beilstein J. Org. Chem. 2019, 15, 863–873, doi:10.3762/bjoc.15.84

• excitation is possible because the probability of TP excitation is proportional to the square of the light intensity [46]. The light-induced generation of nitroxides using the TP excitation technique, i.e., the concentration jump of nitroxides, is one promising method of exploring the role of these species

Synthesis of a novel category of pseudo-peptides using an Ugi three-component reaction of levulinic acid as bifunctional substrate, amines, and amino acid-based isocyanides

• Maryam Khalesi,
• Azim Ziyaei Halimehjani and
• Jürgen Martens

Beilstein J. Org. Chem. 2019, 15, 852–857, doi:10.3762/bjoc.15.82

• . cIsolated yield of one of the diastereomers as pure stereoisomer after several recrystallization steps. ORTEP representation of compound (R*,S*)-4a with thermal ellipsoids at 50% probability. Opposite enantiomer is omitted for clarity. The atom numbering does not follow IUPAC nomenclature. Synthesis of

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• Table S4 in Supporting Information File 1. Structure of the [Zn2L(μ-azo-OH)]+ cation in crystals of [Zn2L(μ-azo-OH)][Zn2L(μ-azo-O)]·4MeCN·3H2O (3'·4MeCN·3H2O). Hydrogen atoms omitted for clarity. Thermal ellipsoids are drawn at the 50% probability level (color codes: C dark grey, H pale gray, N green/or

• of [Cd2L(μ-azo-NMe2)]ClO4·0.5MeOH (6·0.5MeOH). Only one orientation of the disordered azobenzene carboxylato co-ligand is displayed. Hydrogen atoms omitted for clarity. Thermal ellipsoids are drawn at the 50% probability level. Space filling representation of the packing of four [Cd2L(μ-azo-NMe2

• ·8EtOH (7·8EtOH). Only one orientation of the disordered azo-carboxylato co-ligand is displayed. Hydrogen atoms omitted for clarity. Thermal ellipsoids are drawn at the 50% probability level. Left: ORTEP representation of the molecular structure of the [Cd2L(μ-azo-CO2Me)]+ cation in crystals of 8·MeCN

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• the tosylation of 6-monoazido-β-CD in pyridine is selective for the primary rim and gives the three regioisomers with equal probability. Reaction 10 also gave only three components in 37:32:31 area ratio (reaction 10, Figure 6), identified as 6A,6D-, 6A,6C- and 6A,6B-diazido-β-CD, which definitely

Catalyst-free assembly of giant tris(heteroaryl)methanes: synthesis of novel pharmacophoric triads and model sterically crowded tris(heteroaryl/aryl)methyl cation salts

• Rodrigo Abonia,
• Luisa F. Gutiérrez,
• Braulio Insuasty,
• Jairo Quiroga,
• Kenneth K. Laali,
• Chunqing Zhao,
• Gabriela L. Borosky,
• Samantha M. Horwitz and
• Scott D. Bunge

Beilstein J. Org. Chem. 2019, 15, 642–654, doi:10.3762/bjoc.15.60

• 9. aThis product was obtained as an inseparable mixture along compound 8{9,9,6} (see Supporting Information File 1). Thermal ellipsoid plot (40% probability level) of the tris(heteroaryl)methane triad 9{4,7,1}. DFT-optimized structure of 9{4,7,1} triad. 1D- and 2D-based NMR assignments for methylium

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• -interactions with dotted lines (M06-2X-D3/6-311++G(d,p)(PCM=THF)//B3LYP-D3BJ/6-31G(d) at 298 K). X-ray crystal structure of BIFOXSiCl2 (7). H atoms on the chiral backbone are omitted for clarity issues and the ellipsoids are shown with 65% probability. X-ray crystal structure of BIFOXSiCl(OH) (8). H atoms on

• the chiral backbone are omitted for clarity issues and the ellipsoids are shown with 65% probability. X-ray crystal structure ofrac-BIFOXSi(OH)2 (9) forming dimers. H atoms on the chiral backbone are omitted for clarity issues and the ellipsoids are shown with 65% probability. For bond lengths and

• angles see Table 5. X-ray crystal structure of BIFOXSi(OH)2 (9) forming a tetramer. H atoms on the chiral backbone are omitted for clarity issues and the ellipsoids are shown with 65% probability. For bond lengths and angles see Table 5. X-ray crystal structure of BIFOXSi(OH)2 (9) forming a dimeric

New standards for collecting and fitting steady state kinetic data

• Kenneth A. Johnson

Beilstein J. Org. Chem. 2019, 15, 16–29, doi:10.3762/bjoc.15.2

• . More precisely, kcat/Km is equal to the true second order rate constant for substrate binding to the enzyme multiplied by the probability that the bound substrate will be converted to product and released into solution. This principle can be illustrated using the simplest model: The term, k2/(k−1 + k2

• ), gives the probability that the substrate reacts rather than dissociating. With more realistic models, the more complex equations for kcat/Km can still be understood as the product of the rate constant for substrate binding times the probability of forward reaction. Interpretation of steady state kinetic

Mn-mediated sequential three-component domino Knoevenagel/cyclization/Michael addition/oxidative cyclization reaction towards annulated imidazo[1,2-a]pyridines

• Olga A. Storozhenko,
• Alexey A. Festa,
• Delphine R. Bella Ndoutoume,
• Alexander V. Aksenov,
• Alexey V. Varlamov and
• Leonid G. Voskressensky

Beilstein J. Org. Chem. 2018, 14, 3078–3087, doi:10.3762/bjoc.14.287

• annulation patterns. Biologically relevant imidazo[1,2-a]pyridines and chromenes. General view of the molecule 7b in the crystal state (CCDC 1849215). Anisotropic displacement parameters are drawn at 50% probability. Domino formation of imidazopyridines and current work. Scope of the reaction between N