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

• efficiency indeed depends on the effective occurrence of both electrostatic and hydrophobic interactions between the guest and the polymer lattice. Thus, our CaNS nanosponges can be considered as a new class of purely synthetic smart absorbent materials. Keywords: calixarenes; nanosponges; smart materials

• composites loaded with quercetin may show improved cytotoxic activity towards some human breast cancer cell lines [32], likely due to a synergistic action between the polyphenol nutraceutic guest molecule and triazole derivatives coming from the progressive disgregation of the co-polymer carrier. From the

• number of azido groups present in the molecule. The actual accomplishment of the CuAAC reaction, and therefore the formation of the reticulated polymer network, was first assessed by means of FTIR spectroscopy. The FTIR spectra of the propargyloxycalixarene precursor Ca-OP, of the diazide A2 and the

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

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

• hence leads to an overall improved energy efficiency for H2 production. In addition, contrary to the “waste product O2”, FDCA can be further utilized, e.g., for production of polyethylene 2,5-furandicarboxylate (PEF), a sustainable polymer analog to polyethylene terephthalate (PET) and thus represents a

• -refinery based chemicals for a “green” chemical industry [6][7][8]. FDCA was suggested to replace, e.g., terephthalic acid as building block for the formation of polyamides, polyesters, and polyurethanes [6]. Especially, the polymer polyethylene terephthalate (PET), a perpetually used polymer, could be

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• this “green” reaction parameter. To overcome this obstacle, promising approaches are the use of iodoarenes as precatalysts in combination with external co-oxidants and the utilization of specific hypervalent iodine compounds (polymer-supported as well as non-polymeric species), whose reduced forms are

Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes

• Zhensheng Zhao and
• Graham K. Murphy

Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67

• . Experimental evidence suggests that a radical mechanism is involved. Keywords: allene; chlorination; hypervalent iodine; synthetic methods; vinyl chloride; Introduction Organochlorine compounds are vital as polymer precursors [1], as pharmaceuticals [2][3] and agrochemicals [4][5][6] and as functional

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• , namely: (polymer) vesicles, micelles, dendrimers and nanogels. The ability and efficiency of catalytic nanoreactors to carry out organic reactions in water, to perform cascade reaction and their ability to be recycled will be discussed. Keywords: catalysis; dendrimers; green chemistry; nanogels

• Pd catalyst together with a PAA (poly(acrylic acid)) based polymer self-assembled in water [32]. The catalytic activity of the nanostructures was compared to the results achieved with the small molecule analogues of the pincer Pd complex, in a Suzuki–Miyaura coupling. When the reaction of vinyl

• -polyisocyanopeptide (PS-PIAT) and CalB was incorporated within either the lumen or polymer membrane (Figure 5). ROP is usually performed in organic solvent so that hydrolysis reactions can be avoided [17]. However, when nanoreactors were used, polymerization proceeded efficiently in water and without formation of any

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

• Kendra Leahy Denlinger,
• Lianna Ortiz-Trankina,
• Preston Carr,
• Kingsley Benson,
• Daniel C. Waddell and
• James Mack

Beilstein J. Org. Chem. 2018, 14, 688–696, doi:10.3762/bjoc.14.57

• a vast amount of intrigue by the chemical community [24][25][26]. Our research group has continued the study of the Wittig reaction under mechanochemical conditions with the use of a functionalized polymer resin. During these studies, we discovered a few exciting differences between our results and

• . Results and Discussion Liquid-assisted grinding To focus the study, benzaldehyde, benzyl bromide, polymer-supported triphenylphosphine (PS-C6H4-PPh2) and potassium carbonate were ball-milled in a stainless steel vial with two LAG solvents at opposite ends of the dielectric spectrum, as well as a control

• that Cs+ and Br− would be a good pair, since their values are similar. We would expect Rb+ to pair well with Br− for the same reason. To test this idea and to understand the effect of the interaction, we conducted the solvent-free polymer-supported Wittig reaction with various carbonate salts and alkyl

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

• Lin Gan,
• Xianglong Li,
• Xinyi Cai,
• Kunkun Liu,
• Wei Li and
• Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

• Lin Gan Xianglong Li Xinyi Cai Kunkun Liu Wei Li Shi-Jian Su State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Tianhe District, Guangzhou 510640, Guangdong Province, P. R

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• a polymer electrolyte membrane electrochemical reactor (PEMER). Palladium (Pd) nanoparticles were synthesised and supported on a carbonaceous matrix (Pd/C) with a 28 wt % of Pd with respect to carbon material. Pd/C was characterised by transmission electron microscopy (TEM), and thermogravimetric

• analysis (TGA). Cathodes were prepared using Pd electrocatalytic loadings (LPd) of 0.2 and 0.02 mg cm−2. The anode consisted of hydrogen gas diffusion for the electrooxidation of hydrogen gas, and a 117 Nafion exchange membrane acted as a cationic polymer electrolyte membrane. Benzophenone solution was

• ; electrocatalytic hydrogenation; palladium nanoparticles; polymer electrolyte membrane; Introduction Hydrogenation is a common procedure applied in organic chemistry industry based on the use of an external hydrogen source, generally carried out under moderate experimental conditions of high temperature (until 673

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• benzimidazole was chosen as model nucleophile for polybenzimidazole, a polymer commonly applied as a membrane in PEM fuel cells [40]. These reactions provided the 4-benzimidazolyl derivatives 13 and 14 in good yields and the N-triflylbenzamide group proved to be stable under these reaction conditions

Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• years [67]. Some recent highlights have included using polymer backbones to identify GM1 analogues that can give enhanced multivalent interactions [68], evolving glycopolymers using exchangeable ligands [69], and tuning the way the ligands are connected to the polymer backbone for maximum interaction

• [70][71]. For example, using a fragment-based approach, Tran et al. synthesised and evaluated a library of polymer-based hetero-bifunctional ligands and found that some compounds showed low nanomolar multivalent inhibition [68]. Alpha-galactoside 38 (Figure 17) showed the highest activity when

• presented on the polymer scaffold with an IC50 value of 0.005 µM. In contrast, the IC50 value shown by a monomeric version of this heterobifunctional ligand 39 was in the millimolar range, similar to the compound m-nitrophenyl galactopyranoside (4). Fulton and co-workers developed a dynamic combinatorial

Preparation of trinucleotide phosphoramidites as synthons for the synthesis of gene libraries

• Ruth Suchsland,
• Bettina Appel and
• Sabine Müller

Beilstein J. Org. Chem. 2018, 14, 397–406, doi:10.3762/bjoc.14.28

• strategy and syntheses will be described elsewhere. 3. Preparation of trinucleotides by inverse solid-phase synthesis Interestingly, also the use of polymer-supported reagents for H-phosphonate or phosphoramidite activation and phosphite oxidation has been described [34][39], thereby combining the

• ) has a prominent position, appearing as the routinely used polymer [40][41][42][43][44]. The isolation of intermediate and final products from the reaction mixture proceeds by precipitation from diethyl ether and filtration, thus significantly speeding up the process. In addition, the method is

• favorable in terms of producing oligonucleotides at a larger scale, since the reaction proceeds in homogeneous solution on a rather cheap polymer. The synthesis of oligonucleotides on soluble supports has been reviewed recently [45], showing that a variety of soluble polymers and precipitative supports are

Recent developments in the asymmetric Reformatsky-type reaction

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 325–344, doi:10.3762/bjoc.14.21

• containing the two substrates with LiCl was pumped through the zinc column followed by a scavenger cartridge containing QuadraPure polymer-supported sulfonic acid and polymer-supported thiourea. This allowed diastereopure product 36 (98% de) to be obtained in 70% yield. Intramolecular Reformatsky reactions

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• , but EL polymers substituted with iridium complexes have previously been studied in the literature, evidencing the pertinence of the strategy [61]. In this case, charge transport properties are provided by the substituents attached to the polymer chain. As main finding of this work, the detrimental

• . ΔEST values of 0.019 (T31) and 0.021 eV (T32) were also determined by examining the fluorescence and phosphorescence spectra. Interestingly, the bluest EL emission (472 nm) was obtained for the polymer only containing 5 wt % of acceptor T31, with an EQE peaking at 12.1% for these solution-processed

Fluorogenic PNA probes

• Tirayut Vilaivan

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

• probe. One of the earliest examples makes use of PNA probes immobilized on fluorescence-polymer-coated polystyrene microspheres and a quenching DNA strand [106]. The fluorescence of the microsphere was restored upon displacement of the quencher DNA strand by the DNA target in a sequence-dependent manner

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• photoredox-catalyzed radical thiol–ene reaction for polymer postfunctionalization and step-growth addition polymerization (Scheme 4a) [33]. In contrast to Yoon’s conditions, they used [Ru(bpy)3]Cl2 as photocatalyst and N-methyl-2-pyrrolidone as solvent and were able to efficiently couple polybutadiene and

• , trifluoromethyl groups and halides, but iodides led to polymer formation. Li and Wang developed a method for the α-C(sp3)–H thiolation of ethers, using Acridine Red as photosensitizer and tert-butyl hydroperoxide (TBHP) as oxidant (Scheme 38) [73]. They reported that photoexcited Acridine Red performs an energy

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

• -Alcala de Henares, Madrid, Spain Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany Institute of Organic Chemistry with Centre of Phytochemisty, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria (permanent address) 10.3762/bjoc.13.283 Abstract Novel asymmetric monomeric

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• -workers thereafter reported that the trifluoromethylation of (hetero)arenes could also be performed under heterogeneous catalysis [33]. To this aim, the Ru- or Ir-based catalysts were replaced with a mesoporous graphitic carbon nitride polymer (mpg-CN), which offers the advantage of being cheap, metal

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• Institute of Textile Engineering and Polymer Materials, University of Bielsko-Biala, Willowa 2, 43-309 Bielsko-Biala, Poland 10.3762/bjoc.13.269 Abstract The main synthetic routes towards vinylphosphonium salts and their wide applications in organic synthesis are discussed in this review. Particular

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• . This furnished the final product 8 in quantitative conversion with the product stream being readily purified by passage through a scavenging cartridge of QP-SA (a sulfonic acid functionalised polymer). The product 8 was obtained after solvent evaporation as a yellow solid (94%) but required

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

• characterized environment-dependent fluorescence. This property, together with the facile synthetic accessibility, makes it and its derivatives useful for a number of applications, e.g., as materials for organic electronics [1], dyes for mechanochromic materials [2], and fluorescent monomers for polymer

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• supramolecular polymers [9] multifunctional molecules are assembled in a regular manner. To avoid branching, monosubstituted CDs are required for a linear supramolecular polymer of CDs with guest groups attached. Monosubstituted derivatives of CDs [10] include three regioisomers, namely 2I-O-, 3I-O-, and 6I-O

Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

• Paweł Chmielarz,
• Tomasz Pacześniak,
• Katarzyna Rydel-Ciszek,
• Izabela Zaborniak,
• Paulina Biedka and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2017, 13, 2466–2472, doi:10.3762/bjoc.13.243

• macroinitiator was received for the first time by the transesterification reaction of quercetin with 2-bromoisobutyryl bromide. In accordance with the “grafting from” strategy, a naturally-occurring star-like polymer with a polar 3,3',4',5,6-pentahydroxyflavone core and hydrophobic poly(tert-butyl acrylate

• polymerizations was well-controlled by applying optimal potential values during preparative electrolysis to prevent the possibility of intermolecular coupling of the growing polymer arms. This appears to be the first report using on-demand seATRP for the synthesis of QC-(PtBA-Br)5 pseudo-star polymers. The

• naturally-derived macromolecules showed narrow MWDs (Đ = 1.08–1.11). 1H NMR spectral results confirm the formation of quercetin-based polymers. These new flavonoid-based polymer materials may find applications as antifouling coatings and drug delivery systems. Keywords: flavonoids; on-demand seATRP

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

• promoting solid-state reactions [8][9][10][11]. Polymer-assisted grinding (POLAG) is another variation of mechanochemistry, very recently disclosed and making use of polymers to stimulate the reaction [6][12]. Concerning the synthesis of molecular compounds and molecular crystals [2][13][14][15

• liquid led to the formation of a 1D coordination polymer monohydrate, a tetrahydrate complex and an octahydrate, respectively (Figure 2) [7][29]. BioMOFs based on generally regarded as safe (GRAS), bioactive or endogenous linkers for the encapsulation of APIs Another approach to build a BioMOF consists

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• an efficient regioselective generation of 1,4-disubstituted 1,2,3-triazoles [1][2][3]. After their discovery [1], click reactions affording 1,2,3-triazoles rapidly became important for simple and robust binding of versatile molecules and for the building of stable polymer structures [4]. At the same

• solution, but these reactions are usually much slower [31]. Also, click polymerization was applied using a ball-milling process with no significant influence on the integrity of the polymer chain [27][32]. Herein we have studied the efficiency of copper catalysts with Cu(0), Cu(I) and Cu(II) oxidation