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

• that permits using long-wavelength irradiation to deeply penetrate through a reaction medium and material surface and activate the bulk of the material. Congreve, Rovis, Campos, and co-workers utilised triplet fusion upconversion to drive a series of homogeneous photoredox transformations with >700 nm

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

• Liliia Moshniaha,
• Marika Żyła-Karwowska,
• Joanna Cybińska,
• Piotr J. Chmielewski,
• Ludovic Favereau and
• Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

• ], with FeCl3 being particularly notable for its versatility, ease of use, and low price [5]. Nevertheless, the synthetic utility of oxidative couplings is often limited by several factors [6]. Consequently, incomplete ring fusion and various side reactions, e.g., chlorination [7], or unexpected

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

• exhibits a narrow energy gap (1.78 eV) and a lower LUMO energy level than the parent peropyrene without the fusion of the five-membered rings. In addition, the effects of the peri-fused pentagons on the aromaticity and molecular orbitals of 1 were evaluated by theoretical calculations. This work presents

Synthesis of triphenylene-fused phosphole oxides via C–H functionalizations

• Md. Shafiqur Rahman and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2020, 16, 524–529, doi:10.3762/bjoc.16.48

• -conjugated functional molecules [1][2][3][4][5][6][7][8][9]. Its inherently unique electronic structure, along with opportunities to modify the phosphorus center and the periphery by substitution or ring fusion, have stimulated chemists to explore a structurally diverse range of phosphole derivatives with

• -containing ladder molecules and their application as fluorescence probes for biological imaging [10][11]. Marinetti extensively studied the synthesis of phosphahelicenes with linear fusion of the phosphole and the carbohelicene units [12], and their applications in asymmetric catalysis [13] and organic light

• for the construction of the phosphole ring as well as for the π-extension/fusion of the PAH moiety, which should be smoothly implemented into the overall synthetic planning. In this context, we have recently reported the synthesis of novel phosphahelicenes that featured angular fusion of the phosphole

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• starting material, but also ring fusion to selenophene was achieved by Cu-catalyzed C–Se cross-coupling reaction [28]. The detailed geometric structure and the packing behaviour in the solid state of triacenes 2–4 have been elucidated by single crystal X-ray structure analysis and X-ray diffraction on

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• heavy oils. Besides the fusion of the steroidal nucleus to heterocycles by MCRs, there is a whole field of research developed by Tietze and co-workers in the 90’s dealing with the construction of heterosteroids, D-homosteroids (steroids with all 6-membered rings) and azasteroids (steroids with a

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

• , Figure 1) are generated, while if such fusion takes place between the 4- and 5-positions of the γ-lactam ring, 2-oxindoles (also named as indolin-2-ones III, Figure 1) are formed. The isoindolinone structural motif is a part of the core of many natural products [2]. To cite some examples, cichorine [3

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• in the catalytic action of various membrane-related enzymes, such as protein kinase C (PKC) isoforms [45]. Therefore, the development of strategies for visualization of acylglycerols in cellular environments by their fusion with fluorescent molecular labels is in high demand [46]. As a result, once

Thermophilic phosphoribosyltransferases Thermus thermophilus HB27 in nucleotide synthesis

• Ilja V. Fateev,
• Ekaterina V. Sinitsina,
• Aiguzel U. Bikanasova,
• Maria A. Kostromina,
• Elena S. Tuzova,
• Larisa V. Esipova,
• Tatiana I. Muravyova,
• Alexei L. Kayushin,
• Irina D. Konstantinova and
• Roman S. Esipov

Beilstein J. Org. Chem. 2018, 14, 3098–3105, doi:10.3762/bjoc.14.289

• 23d+, respectively. The resulting recombinant plasmid pER-TthHPRT contained fusion gene HPRT-HisTag coding TthHPRT with a C-terminal His-Tag. The resulting recombinant plasmid pER-TthAPRT contained the gene APRT coding TthAPRT without any additional sequences. Nucleotide sequences of the cloned genes

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• clutch, a common technical device used in motor vehicles. Furthermore, rotaxane 23 can be used as novel supramolecular gearing system for the transmission of rotational motion at the molecular level. 5. Rotacatenanes In 2011, the group of Stoddart described the fusion of a rotaxane and a catenane, a so

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• dye are regenerated. This principle has enabled, for example, real-time monitoring of enzymatic activity [18][19][20], the detection of membrane-transport activity [21] and membrane fusion [22], and even cellular imaging appears to be a potential future prospect [23][24]. However, most combinations of

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• , good flexibility in terms of substitution, and an unprecedented fusion pattern of the produced heterocycles. In view of the fact that the constructed 1,2,4-triazolobenzodiazepines represent a class of N-containing fused heterocycles with a new type of scaffold that is biologically interesting, the

Design and biological characterization of novel cell-penetrating peptides preferentially targeting cell nuclei and subnuclear regions

• Anja Gronewold,
• Mareike Horn and
• Ines Neundorf

Beilstein J. Org. Chem. 2018, 14, 1378–1388, doi:10.3762/bjoc.14.116

• calculated R-values, which were 0.83 for N50-sC18* and 0.70 for NrTP-sC18* [25]. In agreement with our recent studies sC18* exhibited an α-helical character in TFE solution (data not shown) [19]. Thus, the helical character of the novel fusion peptides likely results from the sC18* part. Furthermore, N50

• accumulated particularly around the nucleus. In addition to that, a large fraction was also centered within the nuclei and nucleoli. For the fusion peptide NrTP-sC18* a strong accumulation within the nucleoli of both cell lines was visible. Thus, former results about the preferential localization within the

• whole cell, we performed experiments using a lower peptide concentration of 1 μM. Next to this, also the shorter peptides, namely sC18*, N50 and NrTP alone were tested at these concentrations for 30 and 120 min. Hereby, no uptake at all was detected (data not shown). In contrast, both fusion peptides

Biocatalytic synthesis of the Green Note trans-2-hexenal in a continuous-flow microreactor

• Morten M. C. H. van Schie,
• Tiago Pedroso de Almeida,
• Gabriele Laudadio,
• Florian Tieves,
• Elena Fernández-Fueyo,
• Timothy Noël,
• Isabel W. C. E. Arends and
• Frank Hollmann

Beilstein J. Org. Chem. 2018, 14, 697–703, doi:10.3762/bjoc.14.58

• ABTS·+ by an excess of POD (500 U mL−1). The reactions were performed at 30 °C in oxygen-saturated 50 mM KPi buffer at pH 7.0. Flow reactor experiments PFA microreactor coils (750 μm ID) with a volume of 3 and 6 mL were constructed. The reaction mixture was introduced via a syringe pump (Fusion 200

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• (t = 0), that in creamed emulsions after 1 day reaches as high as 0.7–0.8. Such excellent stability to coalescence in high internal phase emulsions is due to the particle layer on droplet interfaces acting as a barrier to drop fusion. Between 0.20 and 0.50 wt % (middle), although an emulsion forms

Sequential Ugi reaction/base-induced ring closing/IAAC protocol toward triazolobenzodiazepine-fused diketopiperazines and hydantoins

• Robby Vroemans,
• Fante Bamba,
• Jonas Winters,
• Joice Thomas,
• Jeroen Jacobs,
• Luc Van Meervelt,
• Jubi John and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 626–633, doi:10.3762/bjoc.14.49

• -turns [43][44][45] and are also known to bind to a number of biological targets [46][47][48]. Interestingly, the fusion of a triazole ring to a 1,4-benzodiazepine core has resulted in an increase in the biological activity as evident from the different drugs with triazolobenzodiazepine structure such as

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• directly by fusion of thiourea/urea with 5-aminopyrazole 126 in an oil bath at 120 °C. N-Thiocarbamoyl pyrazole derivatives 180 and 183 underwent cyclization with hydrazine hydrate to give 5-(N-triazolyl)aminopyrazole derivative 182 and hydrazinopyrazolo[3,4-d]pyrimidines 185, respectively (Scheme 51). El

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

• Myriam Drouin and
• Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

• dipeptide isostere Lys-ψ[(Z)-CF=CH]-Lys into a fusion inhibitory peptide active against HIV 1, SC29EK, was investigated [49]. Weak to moderate anti-HIV activity was observed for the fluorinated analogues, but the potency was always lower than for SC29EK. This suggested than the H-bonding behaviour was

¹⁵N-Labelling and structure determination of adamantylated azolo-azines in solution

• Sergey L. Deev,
• Alexander S. Paramonov,
• Tatyana S. Shestakova,
• Igor A. Khalymbadzha,
• Oleg N. Chupakhin,
• Julia O. Subbotina,
• Oleg S. Eltsov,
• Pavel A. Slepukhin,
• Vladimir L. Rusinov,
• Alexander S. Arseniev and
• Zakhar O. Shenkarev

Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250

• (JCN). However, the fusion of the azine ring to an azolo fragment increases the number of possible alkylation sites and considerably complicates the analysis of the JCN patterns. This issue, together with the inherently low sensitivity of natural abundance 15N NMR spectroscopy, does not always permit

• -triazolo[1,5-a]pyrimidine [30], 1,2,4-triazolo[5,1-c][1,2,4]triazinone [31] and tetrazolo[1,5-b][1,2,4]triazinone [32] can be obtained by the fusion of an azine ring to an azole fragment. This method can be used for the selective incorporation of 15N atoms in different azolo-azines. Recently, we tested

• . The couplings between adamantane carbons and the nitrogens of the heterocycles are shown in Schemes 1–3. The JCN couplings observed for the C6, C7 and C8a atoms in the heterocyclic moieties of compounds 13-15N2 and 15a,b-15N2 confirmed the [1,5-b]-type fusion between the azole and azine rings in these

Remarkable functions of sn-3 hydroxy and phosphocholine groups in 1,2-diacyl-sn-glycerolipids to induce clockwise (+)-helicity around the 1,2-diacyl moiety: Evidence from conformation analysis by ¹H NMR spectroscopy

• Yoshihiro Nishida,
• Mengfei Yuan,
• Kazuo Fukuda,
• Kaito Fujisawa,
• Hirofumi Dohi and
• Hirotaka Uzawa

Beilstein J. Org. Chem. 2017, 13, 1999–2009, doi:10.3762/bjoc.13.196

• glycerophospholipids are around 90%, which permits the presence of the tg conformer by ca. 10%. Note, that the tg conformer is crucial [32][33] because the antiperiplanar relation is thought to deform lamellar phases and trigger membrane fusion. With respect to the antiperiplanar tg conformer, Hauser et al. [10

A recursive microfluidic platform to explore the emergence of chemical evolution

• David Doran,
• Marc Rodriguez-Garcia,
• Rebecca Turk-MacLeod,
• Geoffrey J. T. Cooper and
• Leroy Cronin

Beilstein J. Org. Chem. 2017, 13, 1702–1709, doi:10.3762/bjoc.13.164

• , selection, fusion, and propagation. As a proof of principle, in addition to the working individual modules, we present data showing the osmotic exchange of glycylglycine containing and pure aqueous droplets, showing that the fittest droplets exhibit higher osomolarity relative to their neighbours, and

Framing major prebiotic transitions as stages of protocell development: three challenges for origins-of-life research

• Ben Shirt-Ediss,
• Sara Murillo-Sánchez and
• Kepa Ruiz-Mirazo

Beilstein J. Org. Chem. 2017, 13, 1388–1395, doi:10.3762/bjoc.13.135

• generation. Nevertheless, such division would be still stochastic, producing a significant amount of non-viable progeny, in a context in which protocell fusion and mixing would still be rife [43]. At later stages (Figure 1c) protocells getting closer to LUCA (the ‘last universal common ancestor’ species

• collaborative interactions that probably played non-trivial roles in that sense. In fact, those collective dynamics could trigger (through protocell fusion and recombination of complementary components) functional (re-)integration events beyond the minimal compartmentalized chemistries that were under primary

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

• set of 48 chromosomes (their number in apes) to 46 (their number in man) in a sexed species. Starting with accidental fusion of two chromosomes, a ratchet-like continuum of changes must have distanced us from our ape ancestors. In the same way, it is implausible that there was only one origin of life

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• distributed within the disks or not. It is also conceivable that a partial demixing occurs inside the disk and that bolalipid molecules are accumulated at the rim of this disk stabilizing them against fusion into larger aggregates. With increasing amount of bolalipid, micellar structures became dominant. It

Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• (GFP) fusion protein was functionally expressed in insect Sf9 cells by the BAC-TO-BAC® baculovirus expression system. A two-step procedure to purify the GAT1/GFP fusion protein from insect Sf9 cells has been established and involves immunoaffinity chromatography using self-prepared anti-GFP antibodies

• and size-exclusion fast protein liquid chromatography (SE-FPLC). A yield of 200–300 μg of the GAT1/GFP protein could be purified from 400–600 mL of infected Sf9 cells. The purified protein was analyzed by transmission electron microscopy (TEM), which revealed that the GAT1/GFP fusion protein was

• efficient observation of the expression of the protein of interest, and has a known crystal structure [28][29] for future structural studies. Results and Discussion Expression and characterization of the GAT1/GFP fusion protein in insect cells Construction and analysis of the GAT1/GFP recombinant