Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• excited state energy and redox potentials to interact with additives [13]. Parallel to this, the environmental issues impose the use of new polymerization methods that are safer for the manipulator, contribute to lower the amount of released volatile organic compounds and can reduce the energy consumption

• . Parallel to this, 4CzIPN was also used as an organoredox catalyst for the alkylation of heteroarenes [85], the oxidation of silicates [86], the alkylation of imines [87], the α-arylation/heteroarylation of 2-trifluoroboratochromanones [88]. In these different situations, comparisons with reference

MoO₃ on zeolites MCM-22, MCM-56 and 2D-MFI as catalysts for 1-octene metathesis

• Hynek Balcar,
• Martin Kubů,
• Naděžda Žilková and
• Mariya Shamzhy

Beilstein J. Org. Chem. 2018, 14, 2931–2939, doi:10.3762/bjoc.14.272

• oligomerization in these blank experiments is several times higher than that achieved over metathesis catalysts: it may be due to the partial capping of support acid sites with Mo species catalysts and also due the parallel consumption of 1-octene in metathesis. Figure 5b shows oligomerization of 1-octene, 2

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• developed based on well-defined metal complexes such as metalloporphyrins and metal–salen complexes [15][16][17][18][19][20][21]. In parallel to the development of catalysts, new polyester materials also were prepared by employing unprecedented monomers or by the combination with other polymerization

Dispersion-mediated steering of organic adsorbates on a precovered silicon surface

• Lisa Pecher,
• Sebastian Schmidt and
• Ralf Tonner

Beilstein J. Org. Chem. 2018, 14, 2715–2721, doi:10.3762/bjoc.14.249

• placing the cyclooctyne molecule in an upright orientation (molecular C2 axis aligned parallel to the z axis of the cell), with the triple bond aligned parallel to the y axis of the cell, the triple-bond centre located vertically above a lower surface atom (Sidown) at a height corresponding to a vertical

• with one adsorbate 1 and unit cell used in the PES scans (orientation of second adsorbate and scan path indicated) shown in Figure 5. Frozen PES scans of 1 along path indicated in Figure 4 (C2 axis parallel to z, C≡C parallel to y, Δz(Siup–Ctriple) = 5 Å) on (a) the clean and (b) the precovered surface

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• to a decline in the development of new antibiotics, with very few new antibiotics addressing a novel mode of action being brought to the market over the last four decades [3]. In parallel with the decline of new antibiotics, resistance towards these widely used drugs has evolved at a high pace and

Comparative cell biological study of in vitro antitumor and antimetastatic activity on melanoma cells of GnRH-III-containing conjugates modified with short-chain fatty acids

• Eszter Lajkó,
• Sarah Spring,
• Rózsa Hegedüs,
• Beáta Biri-Kovács,
• Sven Ingebrandt,
• Gábor Mező and
• László Kőhidai

Beilstein J. Org. Chem. 2018, 14, 2495–2509, doi:10.3762/bjoc.14.226

• inducer activity of Dau was also manifested in the pattern of cell cycle phases; the percentage of sub-G1 phase representing apoptotic cells (cell fragments) was increased after cells were treated with 10−5 M Dau up to 14.1% compared with 3.4% of the control. In parallel, a decrease in the proportions of

• modulator effect of the conjugates The dissemination of tumor cells is an important aspect of the tumor progression and could significantly affect the success of the targeted tumor therapy, as well. The first crucial steps in metastasis cascade are the impaired adhesion contacts and in parallel the

• area: 84.2 ± 3.32 – 92.5 ± 3.5; thickness: 95.7 ± 1.94 – 103.1 ± 2.21). Opposite tendencies were shown for [4Lys(Bu)]-GnRH-III(Dau=Aoa), it could increase slightly, but significantly the surface area (114.0 ± 5.64, p < 0.05) and in parallel reduce the optical thickness (85.7 ± 1.85, p < 0.01) at 10−6 M

Microfluidic light-driven synthesis of tetracyclic molecular architectures

• Javier Mateos,
• Nicholas Meneghini,
• Marcella Bonchio,
• Nadia Marino,
• Tommaso Carofiglio,
• Xavier Companyó and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2018, 14, 2418–2424, doi:10.3762/bjoc.14.219

• (up to >98%) and virtually complete diastereocontrol (>20:1 dr). The method is easily scaled-up to a parallel setup, furnishing 948 mg of product over a 14 h reaction time. Finally, a series of manipulations of the tetracyclic scaffold obtained gave access to valuable precursors of biologically active

• spanning from 41% to 72% (Figure 3). In order to demonstrate the easy scalability of the present method (Scheme 1) two MFPs were used in a parallel setup producing 948 mg of 4a after 14 h with an overall productivity rate of 0.196 mmol·h−1 [15]. Subsequently, a series of manipulations were conducted on

• or 5. Generality and limits of the light-driven [4 + 2] cyclization reaction between 2-MBP 1a–g and coumarins 2a–c under MFP setup. *Residence time was 60 min. Generality and limits of the light-driven [4 + 2] cyclization reaction between 2-MBP 1a–f and chromone (3a) under MFP setup. MFP parallel

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• ellipsoids are drawn at the 50% probability level and H-atoms are shown as small spheres of arbitrary size. Hydrogen bonds are shown as dashed lines. The crystal packing of 8 shows the intramolecular hydrogen-bonding network (projection parallel to the x-axis). N- and S-conformation for cyclonucleoside 8. B

A challenging redox neutral Cp*Co(III)-catalysed alkylation of acetanilides with 3-buten-2-one: synthesis and key insights into the mechanism through DFT calculations

• Andrew Kenny,
• Alba Pisarello,
• Arron Bird,
• Paula G. Chirila,
• Alex Hamilton and
• Christopher J. Whiteoak

Beilstein J. Org. Chem. 2018, 14, 2366–2374, doi:10.3762/bjoc.14.212

• energy difference between the C–H activation and C–C bond formation steps makes identification of the rate limiting step difficult by DFT calculations alone, however, parallel kinetic isotope effect (KIE) experiments do suggest that the C–H activation step is not rate limiting (KIE = 1.3), which is not

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• the form found in a confirming crystal structure [6]. Parallel reactions were conducted with Grubbs' second generation catalyst and the nitro-Grela catalyst [36]. However, the combined yields of 2 diminished. 2. Diphosphorus precursors Since the yields of the cage like diphosphine diboranes 2·2BH3 in

• easily deprotected to give the respective isomers of the dibridgehead diphosphine 2 in high yields. Since phosphine oxides are also easily converted to phosphines, one could consider parallel approaches to 2 via metatheses of the phosphine oxide (O=)P((CH2)6CH=CH2)3 (1(=O)) or diphosphine dioxide (H2C=CH

Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

• Lu Yang,
• Yuwei Wu,
• Yiming Yang,
• Chengping Wen and
• Jie-Ping Wan

Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210

• byproduct (entry 1, Table 1). Varying the additive to AcOH didn’t lead to an improved result (entry 2, Table 1). To our delight, the parallel entry without using any catalyst or additive afforded 3a with identically good yield (entry 3, Table 1). With this encouraging result, we then carried out a

Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives

• Jiao-Na Han,
• Cong Du,
• Xinju Zhu,
• Zheng-Long Wang,
• Yue Zhu,
• Zhao-Yang Chu,
• Jun-Long Niu and
• Mao-Ping Song

Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183

• radical approach may be involved in the reaction. Moreover, in the parallel experiments, a KIE value of 1.1 was observed between 1a or [D1]-1a with 2a, which indicates that Co-catalyzed C–H bond cleavage should not be the rate determining step (Scheme 3, reaction 3). On the basis of the above studies and

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• experimental set-ups and even automated self-optimizing platforms were also tested [33]. The natural evolution was an archetype for the multistep flow synthesis. The integration of in-line separation has taken the confidence of the synthesis community one step ahead [21][34][35]. In parallel to this, in-line

A hemicryptophane with a triple-stranded helical structure

• Augustin Long,
• Olivier Perraud,
• Erwann Jeanneau,
• Christophe Aronica,
• Jean-Pierre Dutasta and
• Alexandre Martinez

Beilstein J. Org. Chem. 2018, 14, 1885–1889, doi:10.3762/bjoc.14.162

• parallel peptide chains coil about each other in a triple stranded left-handed helical structure. Its high thermal and mechanical stability results mainly from the numerous hydrogen bonds found in the triple helix framework [2]. Bioinspired structures, based on peptide backbones, have been built, allowing

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• cavity is represented as ‘h’, defined as the measured distance from the centroid of the lower-rim host carbon atoms to the nearest endo guest non-hydrogen atom. In the X-ray structure of 3@BrC6 (Figure 2a), guest 3, oriented parallel to the host aromatic rings (h = 3.43 Å) is positioned in one corner of

• the cavity with only the proton meta- to the N–O group interacting with a host aromatic ring. This short contact C–H···π(host) interaction is about 2.65–2.85 Å long. In 4@BrC6 (Figure 2b), once again guest 4 is oriented parallel to the host aromatic rings (h = 3.38 Å) and the H–G recognition occurs by

• example, in 6@BrC6 (Figure 2d) and 7@BrC6 (Figure 2e), guests 6 and 7 have h = 3.23 Å and 3.50 Å, due to their steric demands. However, in complex 8@BrC6 (Figure 2f) the unhindered para-methoxy group facilitates 8 to sit deep inside the cavity at h = 2.82 Å. The guest’s parallel orientation to the host

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• previously reported nanosystems as polymeric nanoparticles. In covalent series, G-1 dendron D-N

  NH itself (as unexpected reference) self-assembled into nanospheres with a high D value (694 nm). We ascribed this packing ability to three basic π stacking interactions [72] associating stratified parallel

• solution, the reaction conditions were found mandatory to the high solvation of the G-0 and G-1 dendrons exhibiting a major (anti–anti) (parallel) rotamerism of the peripheral 4-(n-octyloxy)phenyl units about the C(s-triazine)–N(exocyclic) partial double bonds. The final iterative synthetic step was

• investigations revealed (i) the regular shape in solution of the terminal 4-(n-octyloxy)phenyl units (“parallel”, anti–anti), (ii) the propeller arrangement, in the case of the angular connections of G-1 dendrons around the m-trivalent core, (iii) the vaulted shapes of G-2 dendrimers and (iv) in one case, the

Drug targeting to decrease cardiotoxicity – determination of the cytotoxic effect of GnRH-based conjugates containing doxorubicin, daunorubicin and methotrexate on human cardiomyocytes and endothelial cells

• Livia Polgár,
• Eszter Lajkó,
• Pál Soós,
• Orsolya Láng,
• Marilena Manea,
• Béla Merkely,
• Gábor Mező and
• László Kőhidai

Beilstein J. Org. Chem. 2018, 14, 1583–1594, doi:10.3762/bjoc.14.136

• helps to compare cytotoxic efficacy (IC50) of the 15 GnRH-based antitumor conjugates in 3 reference tumor cell lines representing the most frequent malignancies (breast cancer – MCF-7, colorectal adenocarcinoma – HT-29 and acute monocytic leukemia – MonoMac6). In parallel, the cardiotoxic effects of the

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• iodoarenes, which are released in stoichiometric amounts in any reaction mediated by λ3- or λ5-iodanes. In parallel to the development of solid-supported reagents or reactions catalytic in iodine, a third strategy has emerged to address this issue in terms of sustainability. The atom-economy of

• investigated and significant achievements have been reported making iodine compounds now useful organocatalysts in asymmetric synthesis (reaction 2 in Scheme 1a) [15][16][17][18][19][20][21][22][23][24]. In parallel to these investigations, a third strategy has been envisaged with the development of tandem

• complex. The group of Sodeoka, in parallel, has described the same 1,2-difunctionalization reaction of alkenes and alkynes with 5 in the presence of [Cu(MeCN)4]PF6 as the catalyst (Scheme 5a) [37]. It should be pointed out that this copper(I) complex was previously described by Szabó as a poor catalyst in

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• crucial for the PLQY attained. In the remarkable case of the crystalline film of complex Pt(fppz)2, the molecular plane of the square-planar compound was mostly perpendicular respect to the substrate and hence, the 3MMLCT photoluminescence dipole lies almost parallel to it. The architecture of the

• value as high as 38.8%, which approaches the maximum EQE estimated value of ca. 45%. This latter could be achieved in the case of a phosphor with 100% of PLQY with a fully parallel emitting dipole. The beneficial effect of the emitting dipole orientation on the light outcoupling efficiency was further

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

• Jonas Weidner,
• Stefan Barwe,
• Kirill Sliozberg,
• Stefan Piontek,
• Justus Masa,
• Ulf-Peter Apfel and
• Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

• window between 1.2 V to 1.5 V vs RHE, where HMF oxidation is facilitated by all investigated catalyst materials. However, parallel O2 evolution at slow rates cannot be fully excluded. For a comparison of the HMF oxidation activity of the investigated catalysts, two performance criteria were taken into

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

• Claudia Lar,
• Adrian Woiczechowski-Pop,
• Attila Bende,
• Ioana Georgeta Grosu,
• Natalia Miklášová,
• Elena Bogdan,
• Niculina Daniela Hădade,
• Anamaria Terec and
• Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

• -triazine unit and the planes of the two caps are parallel. The central triazine rings in 2 are close to each other, the distance between the heterocycles being 3.63 Å. This value is smaller compared to the distance (3.72 Å) measured between the benzene molecules in their sandwich configuration [40], but it

Are dispersion corrections accurate outside equilibrium? A case study on benzene

• Tim Gould,
• Erin R. Johnson and
• Sherif Abdulkader Tawfik

Beilstein J. Org. Chem. 2018, 14, 1181–1191, doi:10.3762/bjoc.14.99

• superpositions or pseudopotentials. Firstly, we use the electronic structure codes to calculate energies E(R) directly. We then fit E(R) = E∞ – C6/R6 to the last five points of the parallel configuration data to find E∞, the extrapolated energy of two monomers, which lets us determine interaction energies U(R

• energy for the parallel configuration of the benzene dimer (labelled P – with D6h symmetry). Despite having a minimum as a function of distance between the two centres, this arrangement is unstable as the dimers wish to slide apart sideways (see later discussion on Figure 3) to reduce electrostatic

• energetically very close to it. Here the balance of energetic contributions is more strongly skewed to dispersion, and it is expected that vdW dispersion corrections should work better than for the parallel configuration shown in Figure 1. Indeed, the successful methods for the parallel geometry (XDM, MBD, FI

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• eight Hoogsteen-paired hydrogen bonds to form a tetrad (Figure 1) has further enhanced our understanding of the diversity of DNA shapes and structures. In a parallel tetramolecular quadruplex d(TG4T), the features of nucleotides at each base resemble that of the B-DNA (C2’-endo sugar pucker, anti

•  10. Minor groove complex formation between DNA duplex and Hoechst 33258 is shown in Figure 7b [82]. X-ray crystallographic and NMR studies confirmed that Hoechst 33258 binds to the A·T-rich sequences in minor groove with the planar benzimidazole groups are oriented parallel to the direction of the

Correlation effects and many-body interactions in water clusters

• Andreas Heßelmann

Beilstein J. Org. Chem. 2018, 14, 979–991, doi:10.3762/bjoc.14.83

• -bonded structure to the second one that is characterised by parallel dipoles of the two water molecules. Compared to this, the dispersion interaction hardly changes upon a disordering of the hydrogen atoms. While it has a minimum, too, at the equilibrium structure, for the other two structures it lies

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• ]. This culminated in Schwander and Signer isolating eight grams of pure material [63] from which high quality X-ray diffraction images (including "Photograph 51") [66] were obtained and its double-helical structure evinced [67]. Parallel to Miescher’s work on salmon sperm, Kossel reported the isolation