Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

• Lidia A. Smyshliaeva,
• Mikhail V. Varaksin,
• Pavel A. Slepukhin,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2018, 14, 2618–2626, doi:10.3762/bjoc.14.240

• functional derivatives of carboranes, in particular heterocyclic ones, are undeniably of increased interest in the chemistry of organoboron compounds due to wide opportunities to use these boron-enriched substances as diagnostic tools for tumor radio imaging [4][5][6][7], promising agents for boron neutron

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

• . [4Lys(Bu)]-GnRH-III(Dau=Aoa) possessing the butyryl side chain acting as a “second drug” proved to be the best candidate for targeted tumor therapy due to its cytotoxicity and immobilizing effect on tumor cell spreading. The applicability of impedimetry and holographic phase imaging for characterizing

• parameters – migration (shortest distance), motility (actual path) and motility speed (ratio of actual path and time) were quantified by tracking single cells in time-lapse videos recorded by a HoloMonitorTM M4 microscope (Phase Holographic Imaging AB, Lund, Schweden). Based on the results, the GnRH-III(Dau

• imaging are useful and suitable techniques for the characterization of cancer cell behavior and for the evaluation of effects of drug targeting conjugates with small structural differences (e.g., length of the side chain in 4Lys). Based on the overall cell biological effects of [4Lys(Bu)]-GnRH-III(Dau=Aoa

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• limited to terminal alkynes. Additionally, they applied this methodology to design a mitochondria-targeted imaging dye from electron-withdrawing formyl-substituted indoles and alkynes. Later, Maji’s group reported an N-tert-butyl amide-directed mono- and di-alkenylation reactions using a cobalt catalyst

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

• (BODIPYs) with an aniline substituent in the meso-position as fluorescent dyes in this type of anchor approach (Figure 1). BODIPYs are a class of fluorescent dyes that are particularly suitable for applications in medical imaging, and as fluorescent labels in biology, biochemistry and related fields [29

• stability under various conditions, particularly under physiological conditions. Although most BODIPYs are insensitive to pH changes, pH-activatable optical probes for cancer imaging have been reported, in which an aniline substituent in the meso-position of the BODIPY core led to efficient fluorescence

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• its receptor [44][45][46], clustered RGD-containing compounds were developed and were shown to exhibit attractive biological properties for the imaging of tumors [47][48][49][50] and for the targeted drug delivery [51][52][53]. In the course of designing phototherapeutic agents that could specifically

Natural and redesigned wasp venom peptides with selective antitumoral activity

• Marcelo D. T. Torres,
• Gislaine P. Andrade,
• Roseli H. Sato,
• Cibele N. Pedron,
• Tania M. Manieri,
• Giselle Cerchiaro,
• Anderson O. Ribeiro,
• Cesar de la Fuente-Nunez and
• Vani X. Oliveira Jr.

Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144

• 2.0 μmol L−1 staurosporine in water (positive control). The apoptosis assay was performed according to Matias et al. [36]. AFM measurements The AFM imaging of MCF-7 cells untreated (control) and treated with peptide (50 μmol L−1 solutions of Dec-NH2 and [Leu]8-Dec-NH2, which presented low activity

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• different alkyl diazides A1–A4 (Scheme 1b), in which the two azido groups are separated by spacers having different length and rigidity. The materials obtained were characterized by means of combined spectroscopic (FTIR, solid state 13C{1H} CP-MAS NMR), calorimetric (DSC) and imaging (SEM) techniques. Then

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

• including photocatalysis [6], bio-imaging [7][8], and solar-energy conversion [9], just to cite a few. Thompson and Forrest reported in 1998 on the first example of a phosphorescent emitter, namely 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (Pt(OEP)), used as dopant for the fabrication of

• found numerous applications as emitting materials in areas such as emitters in PhOLEDs [55][56] and luminescent probes in bio-imaging [57][58][59]. Noteworthy, NIR-emitting OLED were fabricated by using complexes 23g and 23h, which presented a π-delocalized substituent at the 5-position of the central

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

• , thereby changing the efficiency of the FRET process between the two fluorophores and exhibiting a significant red shift in the emission spectrum. Moreover, the conjugate 43 could be used as an attractive tool for imaging of nuclear DNA in the cells due to its low cytotoxicity. A series of water-soluble

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• presence of oxygen, rendered his observation puzzling for scientists, who still struggle to elucidate the complete mechanism of action of diseased cells. Following the Warburg effect, 18F-deoxyglucose positron emission tomography (FDG–PET) imaging was developed in order to visualize the phenomenon of

Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery

• Sabine Schuster,
• Beáta Biri-Kovács,
• Bálint Szeder,
• Viktor Farkas,
• László Buday,
• Zsuzsanna Szabó,
• Gábor Halmos and
• Gábor Mező

Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64

• cytometry, the cellular uptake and localization of K1, K2, 1, 2, 4 and 5 were studied on MCF-7 cells by CLSM. After 6 h incubation with the GnRH-III–Dau conjugates (c = 10 µM, 40 µM and 160 µM), MCF-7 cells were fixed and prepared for confocal laser scanning imaging. In order to gain insight into a possible

• analyzed by FACSDiVa (BD Bioscience) 5.0 software. Confocal microscopy imaging Cells were seeded to cover glass containing (thickness 1, Assistant, Karl Hecht GmbH & Co KG, Sondheim/Rhön Germany) 24-well plates one day prior to the experiment in complete cell medium. Treatment was performed in serum-free

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• clamping and, at the same time, as a sensor probe in combination with another dye-labeled DNA probe in a single-tube operation by real-time fluorescence monitoring [86]. More challenging applications of binary PNA probes for imaging mRNA expression in living cells is possible at a proof-of-concept stage

• been successfully employed in one case [111]. A PNA-based strand displacement probe was delivered into mammalian cells by employing cationic shell cross-linked nanoparticles, whereupon its application in the imaging of cellular mRNA expression was demonstrated [112]. Related to the concept of strand

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• quantum yield properties of the new hybrid compounds are promising for many applications such as organic optoelectronics or biological imaging. Conclusion In summary, we have synthesized the first examples of β-porphyrin, meso-corrole substituted directly linked porphyrin–corrole hybrid compounds via a

Microfluidic radiosynthesis of [¹⁸F]FEMPT, a high affinity PET radiotracer for imaging serotonin receptors

• Thomas Lee Collier,
• Steven H. Liang,
• J. John Mann,
• Neil Vasdev and
• J. S. Dileep Kumar

Beilstein J. Org. Chem. 2017, 13, 2922–2927, doi:10.3762/bjoc.13.285

• Thomas Lee Collier Steven H. Liang J. John Mann Neil Vasdev J. S. Dileep Kumar Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA Advion, Inc., Ithaca, NY, USA Molecular Imaging and Neuropathology Division, New York State

• -18; 5-HT1A; microfluidics; PET; Introduction The development of serotonin 1A receptor (5-HT1AR) agonist radiotracers for applications in molecular imaging with positron emission tomography (PET) has been avidly sought over the past two decades, albeit with limited success. The current status of

• longer half-life enables imaging protocols that can provide a better match of the pharmacokinetics of binding to the half-life of the radionuclide, as well as simplified radiochemistry protocols and the long-term goal of distribution for multicenter clinical trials. Several reports on the use of

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

• Aleksey A. Vasilev,
• Meglena I. Kandinska,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• David Sucunza,
• Juan J. Vaquero,
• Obis D. Castaño,
• Stanislav Baluschev and
• Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

• valuable properties as nucleic acid stains have made these dyes an irreplaceable tool in the active and developing area of bioanalytical chemical research [9][10]. Cyanine dyes have found various bioanalytical applications as soluble DNA intercalators (e.g., in living cell imaging [11] and flow cytometry

Reagent-controlled regiodivergent intermolecular cyclization of 2-aminobenzothiazoles with β-ketoesters and β-ketoamides

• Irwan Iskandar Roslan,
• Kian-Hong Ng,
• Gaik-Khuan Chuah and
• Stephan Jaenicke

Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270

• antimicrobial [35][36], antitumor [37][38][39], antibacterial [40], and anti-allergic agents [41]. In addition, compounds with this backbone are employed as kinase inhibitors and receptors [42][43][44] and as a tracer for PET imaging of β-amyloid plaques [45][46]. The conventional approach for the construction

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

• Futa Ogawa,
• Masanori Takeda,
• Kanae Miyanaga,
• Keita Tani,
• Ryuji Yamazawa,
• Kiyoshi Ito,
• Atsushi Tarui,
• Kazuyuki Sato and
• Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

• the reaction medium. The results suggest that 1 could be used as fluorophore in OFF–ON-type fluorogenic probes. Keywords: dipeptidyl peptidase-4; fluorogenic substrate; fluorometry; small fluorescent molecule; Introduction Fluorescent organic probes have become indispensable for bio-imaging or

• molecular imaging to visualize the presence of species such as particular enzymes and biologically important inorganic ions. In biomedicine, these probes are used for the detection of a wide range of significant biomarkers and are essential for the diagnosis of critical diseases [1][2][3]. Selective and

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

• Clément Ghiazza,
• Anis Tlili and
• Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

• Clement Ghiazza Anis Tlili Thierry Billard Institute of Chemistry and Biochemistry, Univ Lyon, Université Lyon 1, CNRS, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France CERMEP-In vivo Imaging, Groupement Hospitalier Est, 59 Bd Pinel, F-69003 Lyon, France 10.3762/bjoc.13.260 Abstract Herein

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• Organofluorine compounds now play an essential role in the development of new materials for solar cells [1][2][3], radiotracers for PET imaging [4], agrochemicals [5][6], sensitive chemical probes for 19F nuclear magnetic resonance investigation of biological experiments [7][8], and are most widely used in the

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

• Artur Jabłoński,
• Yannic Fritz,
• Hans-Achim Wagenknecht,
• Rafał Czerwieniec,
• Tytus Bernaś,
• Damian Trzybiński,
• Krzysztof Woźniak and
• Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

• investigated towards application as fluorescent cell imaging bioprobes so far. Furthermore, self-assembly studies of pyrene–nucleobases on oligonucleotide templates have not been reported as well. The work presented herein addresses these two problems. Accordingly, in this contribution we report on the

• that, due to significant phototoxic activity, compounds 2 and 3 were not compatible with live cell imaging. On the other hand, accumulation of 4 and 5 was detectable with confocal microscopy, following 15 min incubation of live human cancer HeLa cells with 200 nM of each compound. Both 4 and 5 produced

• results substantiate further studies on pyrene–nucleobase conjugates as nucleic acid fluorescent probes and as cell imaging agents. Experimental General All preparations were carried out using standard Schlenk techniques. Chromatographic separations were carried out using silica gel 60 (Merck, 230–400

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• development of peptide-based contrast agents for 19F imaging [22]. In polypeptides, the incorporation of fluorine can significantly alter the properties of the native molecule. The hydrophobicity [23][24], conformational equilibria [25], and the thermodynamic [26][27][28][29] and kinetic [30][31] folding

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• proteases [7], cruzain 20 [8][9], caspases [10] and peptidyl aminopeptidases [11]. These protease inhibitors show potential for the treatment of Chagas disease [2][9], Huntington’s disease [10], malaria [11], autoimmune diseases [6] and the imaging of tumor associated macrophages [2]. Whereas the carboxylic

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

• Vânia André,
• Sílvia Quaresma,
• João Luís Ferreira da Silva and
• M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

• ], luminescence [67], non-linear optics [68] and magnetism [69], as well as contrast agents for magnetic resonance imaging (MRI) [70] and as drug carriers in systems for controlled drug delivery and release [64][71][72][73][74][75][76][77][78][79][80]. Also under development are new systems with potential use in

• anticancer drugs have also shown that these have potential to be used in fluorescence imaging. The number of reports on MOFs synthesized by mechanochemistry [8][28][50][99][100][101] has been increasing and some in situ studies on the mechanosynthesis of MOFs and coordination polymers are already being

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• investigated for DPP derivatives. The most common applications of organic molecules with THG activity are directed towards all-optical signal processing and optical imaging [30][31]. Hence, as a continuation of our research activity on incorporating heteroaromatic moieties in push–pull molecules [9][10], we

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• pattern of the naphthalene scaffold. Even the smallest polarity change in the solvent system effects their absorption and emission behavior [34][40]. Very recent investigations on naphthaleneimide derivatives revealed enormous phosphorescence lifetimes that are particularly interesting for imaging