N-Heterocyclic carbenes

• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2474–2475, doi:10.3762/bjoc.11.268

• stabilizing effects due to their steric and electronic tunable properties) might be unnecessary. The use of these ligands now extends to numerous fields spanning from fine chemicals to polymer synthesis. The area of main group chemistry has also benefited from these ligands as stabilizing entities. Since the

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• double bond transformations by olefin metathesis have significantly impacted organic and polymer synthesis over the last two decades [1][2][3]. If early works focused on ring-closing metathesis and ring-opening metathesis polymerization, progresses in catalysts performances [4][5] and selectivity have

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• polytetrafluoroethylene membrane with the pore diameter of 0.22 μm. Polymer synthesis (typical) Polyoctenamer (PCOE): Cis-cyclooctene (3.58 g, 32.6 mmol) was added to the 1st generation Grubbs’ catalyst (38.3 mg, 0.0465 mmol) solution in CH2Cl2 (12.2 mL) prepared in a round-bottom glass flask (50 mL) equipped with a

• concentration). As known from the literature [29], Gr-1 cannot initiate a living process of COE and NB so that the obtained polymers are rather polydisperse because of back-biting and chain-transfer reactions (the molar-mass dispersity Ð is close to 2 for PCOE and to 3 for PNB). For more details on the polymer

• synthesis and characterization, see the Experimental section. Light-scattering studies on PCOE and PNB solutions First of all, it was important to find a suitable solvent that provides homogeneity of the reaction media. Chloroform (CHCl3 or CDCl3) was chosen as the best solvent for PCOE/PNB mixtures

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• weights (2000–3000 Dalton), while with butandiol polyesters with higher molecular weights (8000–12000 Dalton) were obtained. Interestingly, the polymers carried functional groups in the chain that could be used for further modifications. For polymer synthesis involving environmentally benign chemicals the

• diester using ethyl α-bromoacetate. The formed diester was copolymerized with PEG using CAL-B (Figure 14). The final product was an effective activator of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) several times better than the free curcumin [66]. The curcumin diester was used in a second polymer

• synthesis with carbinol (hydroxy) terminated polydimethylsiloxane catalyzed by CAL-B [67]. The curcumin moiety retained its fluorescence properties without quenching in thin films prepared from the polymer. Films exposed to low concentrations of vapors of the explosives DNT and TNT absorbed the explosives

Quarternization of 3-azido-1-propyne oligomers obtained by copper(I)-catalyzed azide–alkyne cycloaddition polymerization

• Shun Nakano,
• Akihito Hashidzume and
• Takahiro Sato

Beilstein J. Org. Chem. 2015, 11, 1037–1042, doi:10.3762/bjoc.11.116

• chemistry [8][9][10][11][12] to materials science [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], as well as polymer synthesis [30][31][32][33][34][35][36]. Most of these studies deal with the 1,2,3-triazole moiety just as a linker. However, since 1,2,3-triazole possesses a large

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• various types of aryl groups. At this point, we have chosen the direct arylation of TTF in the presence of a palladium catalyst as a key reaction for the chiral polymer synthesis (Scheme 2) [22]. Thus, the chiral allenes, (R)-9 or (S)-9, react with an active palladium species, prepared in situ from Pd(OAc

CO₂ Chemistry

• Thomas E. Müller and
• Walter Leitner

Beilstein J. Org. Chem. 2015, 11, 675–677, doi:10.3762/bjoc.11.76

• ]. Activation of carbon dioxide by inserting it into metal-alkoxide bonds allows for subsequent applications in polymer synthesis such as the copolymerisation of carbon dioxide with epoxides and other co-monomers [11]. Here, the catalysis with cobalt complexes still presents surprising effects [12]. More

Anomalous diffusion of Ibuprofen in cyclodextrin nanosponge hydrogels: an HRMAS NMR study

• Monica Ferro,
• Franca Castiglione,
• Carlo Punta,
• Lucio Melone,
• Walter Panzeri,
• Barbara Rossi,
• Francesco Trotta and
• Andrea Mele

Beilstein J. Org. Chem. 2014, 10, 2715–2723, doi:10.3762/bjoc.10.286

• transport properties of a drug encapsulated in polymeric scaffolds. The diffusion properties of IP in CDNS can be modulated by suitable polymer synthesis; this finding opens the possibility to design suitable systems for drug delivery with predictable and desired drug release properties. Keywords: cross

• achieved by suitable polymer synthesis. This fact opens the possibility of a rational design of drug delivery/controlled release systems by controlling, inter alia, the transport properties of the encapsulated drug. iii) HRMAS NMR turned out to be a direct, efficient and quick method to gain diffusivity

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• & Bio-Systems, Research Campus Golm, 14424 Potsdam, Germany Humboldt University, Department of Chemistry, Brook-Taylor-Str. 2, 12489 Berlin, Germany 10.3762/bjoc.10.166 Abstract The synthesis of photoswitchable glycooligomers is presented by applying solid-phase polymer synthesis and functional

• the combination of solid phase polymer synthesis and tailor-made building blocks [7][8][9]. Through a stepwise assembly of our functional building blocks, we can now control the kind, number, and spacing of sugar ligands along a monodisperse scaffold. Thus, our precision glycomacromolecules allow for

• azobenzene functionalized with an Fmoc-protected aminomethyl group and a carboxylic acid both para to the N=N bond was used as one building block during solid-phase polymer synthesis of precision glycomacromolecules (see AZO, Figure 1) [19][20][21][22]. The benzylamine fragment was favored over the

Controlled synthesis of poly(3-hexylthiophene) in continuous flow

• Helga Seyler,
• Jegadesan Subbiah,
• David J. Jones,
• Andrew B. Holmes and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170

• mixing of reagents, boosting reaction rates, and safe handling of reactive intermediates. Using a commercial continuous-flow tube reactor [19], we have already demonstrated multigram synthesis of fullerene derivatives by cycloaddition reactions [11] as well as rapid conjugated-polymer synthesis using

The synthesis of well-defined poly(vinylbenzyl chloride)-grafted nanoparticles via RAFT polymerization

• John Moraes,
• Kohji Ohno,
• Guillaume Gody,
• Thomas Maschmeyer and
• Sébastien Perrier

Beilstein J. Org. Chem. 2013, 9, 1226–1234, doi:10.3762/bjoc.9.139

• applications. The establishment in the 1990s of living radical polymerization (LRP, defined as reversible deactivation radical polymerization by the IUPAC), has dramatically changed the polymer-synthesis landscape allowing the easy production of well-defined polymeric materials of desired molecular weights

Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

• Nina Gonsior,
• Fabian Mohr and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 390–397, doi:10.3762/bjoc.8.42

• : cyclodextrin; heterocyclic mesomeric betaine; imidazole; polymer; X-ray single-crystal analysis; Introduction Heterocyclic mesomeric betaines [1] are interesting starting materials for heterocycle and polymer synthesis due to there intriguing chemical properties. They can be broadly classified into four main

A practical microreactor for electrochemistry in flow

• Kevin Watts,
• William Gattrell and
• Thomas Wirth

Beilstein J. Org. Chem. 2011, 7, 1108–1114, doi:10.3762/bjoc.7.127

• the product selectivity. Cycloadditions using the N-acyliminium ions as heterodienes with a variety of dienophiles, such as alkenes and alkynes, give the corresponding [4 + 2] cycloaddition products in high yields [10]. The same authors also reported a successful polymer synthesis using the same

The cross-metathesis of methyl oleate with cis-2-butene-1,4-diyl diacetate and the influence of protecting groups

• Arno Behr and
• Jessica Pérez Gomes

Beilstein J. Org. Chem. 2011, 7, 1–8, doi:10.3762/bjoc.7.1

• both very interesting substrates for polymer synthesis. They could be prepared under mild reaction conditions within 5 h. Moreover, this is an advantageous contribution towards the synthesis of sustainable monomer units because a new α,ω-difunctional substrate class starting from a renewable compound

• Arno Behr Jessica Perez Gomes Chair of Technical Chemistry A, Department of Biochemical and Chemical Engineering, Technische Universität Dortmund, Emil-Figge-Str. 66, D-44227 Dortmund, Germany 10.3762/bjoc.7.1 Abstract Background: α,ω-Difunctional substrates are useful intermediates for polymer

• synthesis. An attractive, sustainable and selective (but as yet unused) method in the chemical industry is the oleochemical cross-metathesis with preferably symmetric functionalised substrates. The current study explores the cross-metathesis of methyl oleate (1) with cis-2-butene-1,4-diyl diacetate (2

Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

• Olubummo Adekunle,
• Susanne Tanner and
• Wolfgang H. Binder

Beilstein J. Org. Chem. 2010, 6, No. 59, doi:10.3762/bjoc.6.59

• polymer synthesis. Alternatively, Grubbs’ third generation catalyst G3 introduced by Grubbs et al. [10] has an ultrafast initiating ruthenium benzylidene. The rate of reaction of G3 with ethyl vinyl ether thus is six orders of magnitude higher than for G2 [10], leading to a faster initiation and often