Combined bead polymerization and Cinchona organocatalyst immobilization by thiol–ene addition

• Kim A. Fredriksen,
• Tor E. Kristensen and
• Tore Hansen

Beilstein J. Org. Chem. 2012, 8, 1126–1133, doi:10.3762/bjoc.8.125

• and separated from reaction mixtures by filtration, this necessitates several steps, as the cross-linked resin must be prepared first by copolymerization, then equipped with thiol functionalities, and finally joined with the Cinchona derivative through thiol–ene coupling. The thiol–ene addition was

• ]. Single step thiol–ene polymerization and Cinchona organocatalyst immobilization With the assortment of building blocks depicted in Figure 1 available, we could now obtain immobilized versions (10–12) of unmodified Cinchona catalysts 1–3 directly by oil-in-water type thiol–ene suspension copolymerization

• occurred. Conclusion We have developed an unusually concise immobilization of Cinchona organocatalysts by thiol–ene suspension copolymerization of polyfunctional thiols and alkenes together with unmodified Cinchona organocatalyst precursors. As such, bead polymerization and catalyst immobilization is

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

• Branislav Husár,
• Norbert Moszner and
• Ivan Lukáč

Beilstein J. Org. Chem. 2012, 8, 337–343, doi:10.3762/bjoc.8.37

• by copolymerization of styrene (99.54 mol %) and MCQ (0.46 mol %), initiated by AIBN at 60 °C and resulting in 10% conversion. FTIR spectroscopy was used to estimate the content of CQ units in the MCQ/S copolymer by interpolation of the peak area of the carbonyl band (1740–1790 cm−1) using a

• % from UV–vis. MCQ is therefore more reactive than styrene, which is in agreement with the copolymerization parameters of structurally similar monomers. Photooxidation of MCQ/S Since it is difficult to follow the structural changes of the CQ structures of the MCQ/S copolymer during photochemical

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• . These chromophores, with free terminal OH-functions, were further used as monomers for copolymerization with polyester, polyuretane, and polymethacrylate (see below). Structurally very similar chromophore 87 (R = H; R1 = CH2CH2OH; R2 = Et) was used for incorporation into the sol–gel hybrid films based

• chromophores with free NH2 and OH peripheral groups, which can be used to link the chromophore to various polymers (Figure 21). These systems were mainly investigated by Ye et al. (Table 14; [18][50][51][52][53][122][123][124]). The polyimides 116–118 (X = NH) were prepared by the copolymerization (Michael

• -diphenylthiophene (BMPDPTH) with chromophore 15f afforded system 119 with significantly enhanced nonlinearity (d33 = 32.2 pm/V) [124] as a result of the π-linker extension through the thiophene and double-bond subunits. Diimidazole 27a (X = NH) was also utilized as a reactive chromophore for copolymerization with

Chiral recognition of ephedrine: Hydrophilic polymers bearing β-cyclodextrin moieties as chiral sensitive host molecules

• Sabrina Gingter and
• Helmut Ritter

Beilstein J. Org. Chem. 2011, 7, 1516–1519, doi:10.3762/bjoc.7.177

• aromaticity and is pharmaceutically relevant (Scheme 1). Recently we described the monomer synthesis of mono-(6-azido-6-desoxy)-β-cyclodextrin with propargylmethacrylate and the copolymerization with N-isopropylacrylamide (NIPAAM) [20]. The properties of the polymer 1 were characterized further by use of size

Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

• Xacobe C. Cambeiro,
• Rafael Martín-Rapún,
• Pedro O. Miranda,
• Sonia Sayalero,
• Esther Alza,
• Patricia Llanes and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172

• -linking agent and in the other case (1b) from a home-made Merrifield resin with 8% DVB (prepared by radical copolymerization of styrene, 4-chloromethylstyrene and DVB, under previously reported conditions [77][78][79]). It is well known that slightly cross-linked (1–2% DVB) polystyrene is microporous in

Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

• Aamer Saeed,
• Madiha Irfan and
• Shahid Ameen Samra

Beilstein J. Org. Chem. 2011, 7, 638–647, doi:10.3762/bjoc.7.75

• of the pyridine ring [20]. Zheng et al. have prepared a new class of copolymers that incorporate pyridine and N-alkyl carbazole alternatively into the main chain by oxidative-coupling copolymerization. These polymers are thermostable, highly soluble, and processable, and the fluorescence spectra of

Regioselective ester cleavage during the preparation of bisphosphonate methacrylate monomers

• Kamel Chougrani,
• Gilles Niel,
• Bernard Boutevin and
• Ghislain David

Beilstein J. Org. Chem. 2011, 7, 364–368, doi:10.3762/bjoc.7.46

• tested, after copolymerization and incorporation, in a desensitizing solution for lithography [22]. More recently we investigated a similar compound 1a for its adhesive or anticorrosive or flame-retardant properties [20][21]. The synthesis of bisphosphonate monomers 1c–7c is described in Scheme 2. Thus

ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering

• Franziska Weichelt,
• Solvig Lenz,
• Stefanie Tiede,
• Ingrid Reinhardt,
• Bernhard Frerich and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, 1199–1205, doi:10.3762/bjoc.6.137

• /bjoc.6.137 Abstract Porous monolithic inorganic/polymeric hybrid materials have been prepared via ring-opening metathesis copolymerization starting from a highly polar monomer, i.e., cis-5-cyclooctene-trans-1,2-diol and a 7-oxanorborn-2-ene-derived cross-linker in the presence of porogenic solvents and

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• many cases on the nanoparticles themselves, i.e., size and size distribution or morphology, and not on the characteristics of the polymer chains (for a given polymer). Functionalized polymers can be obtained by the homopolymerization of a functional monomer or its copolymerization with another (non

• presence of Fe3O4 ferrofluid to yield superparamagnetic particles. Wiechers et al. investigated the copolymerization of 1-vinylimidazole and 2-acrylamido-2-methyl-1-propanesulfonic acid in inverse miniemulsion with an oil-soluble initiator at different pH values [25]. The polymerization was found to be

• faster at neutral pH values and higher molecular weight polymers were produced in miniemulsion compared to solution polymerization as a result of the confinement effect. The same group carried out a similar study with the copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid and 2

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• the immobilization of amino functional targets are obtained in a single polymerization step by grafting-from copolymerization of an active ester monomer from superparamagnetic cores. The comonomer, oligo(ethylene glycol) methyl ether methacrylate, has excellent water solubility at room temperature

• of the superparamagnetic cores in combination with the thermoresponse of the shell. These multifunctional hybrid particles are formed by surface initiated copolymerization of oligo(ethylene glycol) methyl ether methacrylates (labeled as MEMA (M), MEEMA (M’) and OEGMA (O)) with N-succinimidyl

• methacrylate (SIMA) as a methacrylic acid derivative suitable for ATRP [46][47][48]. We have initially investigated the copolymerization behavior of the two monomers in model copolymerization experiments in solution, to ensure proper incorporation of the functional groups and stability of the active ester

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• -controlled process nor does it result in a real living character [41]. However, PNIPAAm homo polymer of Mn = 7500 g/mol could be obtained with a molecular weight distribution of 1.21. After block copolymerization, the molecular weight distribution increased. Nevertheless, for most of the block copolymers the

Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length

• Florian K. Wolf,
• Anna M. Fischer and
• Holger Frey

Beilstein J. Org. Chem. 2010, 6, No. 67, doi:10.3762/bjoc.6.67

• melt copolymerization with hb-PG as macroinitiator via Sn(Oct)2 catalysis afforded well-defined complex polymer structures with predictable molecular weights. In contrast to their linear analogs of comparable molecular weight, the polymers exhibited superior solubility in organic solvents such as DMF

• viscous, non-transparent white oil. Synthetic route to hb-PG-b-(P)GA multi-arm star copolymers in a two-step sequence. The well-established anionic ring-opening multibranching polymerization of glycidol is followed by the Sn(Oct)2-mediated copolymerization of glycolide. SEC-elugrams of the obtained multi

RAFT polymers for protein recognition

• Alan F. Tominey,
• Julia Liese,
• Sun Wei,
• Klaus Kowski,
• Thomas Schrader and
• Arno Kraft

Beilstein J. Org. Chem. 2010, 6, No. 66, doi:10.3762/bjoc.6.66

• protein affinities [8], accompanied in a number of cases with promising protein selectivities [9]. These linear polymers were all prepared by free radical copolymerization in DMF followed by deprotection of the binding monomers in polymer-analogous transformations. Thus, a polymerized bisphosphonate

• BSA (pI < 6) protein affinities vary by less than one order of magnitude. Conclusion In summary, RAFT copolymerization of NIPAM with monomers containing anionic binding sites for basic amino acids led to polymers of low polydispersities which were effective protein binders in buffered aqueous solution

• some cases reaching micromolar or sub-micromolar Kd values. Copolymerization with N-cyclohexylacrylamide introduced additional nonpolar groups beneficial for protein binding, leading to a substantial entropy gain and significantly improving protein affinities. The best pair was a bisphosphonate

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• (s, 5H, 1-H), 4.25 (t, 2H, 2-H, 3J = 1.73 Hz), 4.44 (t, 2H, 3-H, 3J = 1.73 Hz), 4.75–5.30 (7H, 7-H) 6.47 (dd,1H, 4-H, 3J = 10.72 Hz (cis), 3J = 17.34 Hz (trans)). Copolymerization of vinylferrocene 1 and N-isopropylacrylamide 5 An aqueous solution of methyl-β-CD 2 (617.72 mg, 0.47 mmol) was prepared

• and precipitated (c). Lower critical solution temperature of PVFc-co-P(NiPAAM) 7 (1:20) (solid line): 17 °C and complexed NiPAAM with additional methyl-β-CD (dashed line): 19 °C. Homopolymerization of vinylferrocene 1. Copolymerization of vinylferrocene 1 with NiPAAM 5 (1:20).

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

• Olubummo Adekunle Susanne Tanner Wolfgang H. Binder Institute of Chemistry, Faculty of Natural Sciences II (Chemistry and Physics), Martin-Luther University, Halle-Wittenberg, von Danckelmannplatz 4, D-06120 Halle, Germany 10.3762/bjoc.6.59 Abstract We report on the block copolymerization of two

• ™). However, their synthetic profile with respect to the synthesis of block copolymers is largely unexplored. As we recently have reported extensively on the use of ROMP methods in blockcopolymer synthesis [11][12][13], either via direct copolymerization or coupled to postmodification methods via azide/alkyne

New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

• Otman Otman,
• Paul Boullanger,
• Eric Drockenmuller and
• Thierry Hamaide

Beilstein J. Org. Chem. 2010, 6, No. 58, doi:10.3762/bjoc.6.58

• bearing carbohydrate and oligocaprolactone side chains, obtained via copolymerization of a PCL macromonomer and maleic anhydride, and further functionalization by ring opening of the anhydride moiety with amino mannopyranoside. These copolymers were then used as polymer surfactants for the stabilization

• -co-N-vinyl pyrrolidone), were prepared by conventional radical copolymerization using propargyl acrylate and N-vinyl pyrrolidone as comonomers. The reactions were carried out in dry THF at 65 °C under an argon atmosphere with lauroyl peroxide as the initiator. The copolymers were obtained as a white

Synthesis, characterization and photoinduced curing of polysulfones with (meth)acrylate functionalities

• Cemil Dizman,
• Sahin Ates,
• Lokman Torun and
• Yusuf Yagci

Beilstein J. Org. Chem. 2010, 6, No. 56, doi:10.3762/bjoc.6.56

• after polymerization. The second involves direct copolymerization of functionalized monomers [4][5][6]. An increasing topic of interest concerns cooperation of PSUs with epoxy resins via end group functionalization or blending. Engineering thermoplastics based on PSU have been widely used to overcome