Polystyrene amino-functionalized

Montanari and coworkers have been particularly active in this area. They have generally utilized crowns or cryptands having long arms attached to them. These lipophilic arms are typically terminated in a primary or secondary amino function which may serve as a nucleophile in the reaction with a chloromethylated polystyrene residue. 

Phenylfluoren-9-yl polystyrene (Phfl) based resin 49 was applied in the solid-phase synthesis of hydroxyl and amino functions [57,58]. This resin has higher acid stability compared to the structurally similar trityl resin. Final release of the product is accomplished with TFA in high purity (Scheme 19). 

The first solid-phase application of the Ugi four-component condensation, generating an 18-member acylamino amide library, was presented in 1999 by Nielsen and Hoel [53]. The authors described a library generation utilizing amino-functionalized PEG-polystyrene (Tentagel S RAM) as the solid support (Scheme 7.36). A set of three aldehydes, three carboxylic acids, and two isonitriles was used for the generation of the 18-member library. 

Recently, carboxyl- and amino-functionalized polystyrene latex particles were synthesized by the miniemulsion copolymerization of styrene and acrylic acid or 2-aminoethyl methacrylate hydrochloride (AEMH) [70, 71]. The reaction was started by using an oil-soluble initiator, 2,2 -azobis(2-methylbutyronitrile) (V-59). Two types of surfactant, i.e., ionic negatively charged SDS or positively charged CTMA-Cl, and nonionic Lutensol AT50 (which is a PEO hexadecyl ether with an EO block length of about 50 units) were used to stabilize the initial droplets and final particles. 

Musyanovych A, Rossmanith R, Tontsch C, Landfester K (2007) Effect of hydrophilic comonomer and surfactant type on the colloidal stability and size distribution of carboxyl-and amino-functionalized polystyrene particles prepared by miniemulsion polymerization. Langmuir 23(10) 5367-5376... 

Holzapfel V, Musyanovych A, Landfester K, Lorenz MR, Mailander V (2005) Preparation of fluorescent carboxyl and amino functionalized polystyrene particles by miniemulsion polymerization as markers for cells. Macromol Chem Phys 206(24) 2440-2449... 

Musyanovych A, Adler H-JP (2005) Grafting of amino functional monomer onto initiator-modified polystyrene particles. Langmuir 21(6) 2209-2217... 

A peptide library can be synthesized using the SPOT synthesis technique to form a low-density peptide spot array (e.g., 25 spots/cm ). In this method, different peptides are synthesized in situ as low-density arrays on cellulose membrane or paper (8). The volume of Fmoc-amino acids and coupling reagents dispensed creates a specific SPOT size that determines both the scale of reaction and the absolute number of peptides that can be arranged on an area of a membrane. Cotton (another form of cellulose) and polystyrene-grafted polyethylene film segments also have been used as solid supports. Recently, polymeric membranes that are chemically, mechanically, and thermally more stable have been developed, which include hydroxy-functionalized PEG acrylate polypropylene membranes and an amino-functionalized ester-free PEG... 

Linker attachment An amino-functionalized polystyrene or PEG-polystyrene resin may be used as starting material. First, 5-(4-formyl-3,5-dimethoxyphe-noxy)valeric acid (PALdehyde) [122] (4equiv.) and HATU [123] (4equiv.) were dissolved in DMF, DIEA (8 equiv.) was then added, and, after 1 min of pre-activation, this solution was added to the resin (1 equiv.). Coupling was allowed to proceed at 25 °C for 2 h, after which the Kaiser ninhydrin test [81] was negative. 

Polystyrene containing 50% divinylbenzene provides a nonswelling, rigid support that possesses the attractive features of rapid reaction kinetics, efficient washing with organic solvents, and mechanical stability during oligonucleotide synthesis. This support has been derivatized to provide a primary amino functionality (Fig. 2) by the same procedure described for aminomethylated polystyrene resin (see Section II.A). 

Although Ugi reactions can proceed rapidly, reaction times from one to several days are not uncommon. MW conditions could speed up these reactions. Thus, after attachment of poly(ethylene glycol) (PEG)-grafted polystyrene to an amino-functionalized building block, the Ugi reaction has been performed in a domestic MW oven, using a mixture of DCM and MeOH (2 1), with a total irradiation time of 5 min. After cleavage from the resin by treatment with TFA DCM (19 1) for 1 h the desired bisamides 66 were obtained in up to 96% yield. This reduced reaction times by at least a factor of ten compared with conventional reaction conditions. 

Carboxy- and amino-functionaUzed polystyrene nanoparticles have been synthesized by the miniemulsion process using styrene and the functional monomers acrylic acid (AA) or 2-aminoethyl methacrylate hydrochloride (AEMH) as functional comonomers [30,31]. By changing the amount of the comonomer, different surface densities of the charged groups could be realized. Since a fluorescent dye was incorporated inside the nanoparticles, the uptake behavior of different cell Unes could be determined as a function of the surface functionalization [30,31]. It was found that, in general, the uptake of the nanoparticles into the cells increases with increasing functionality on the particle s surface. For HeLa cells, for example, the internalized particle amount was up to sixfold better for carboxy-functionaUzed polystyrene (PS) nanoparticles than for non-functionalized PS particles. For amino functionalized PS nanoparticles, an up to 50-fold enhanced uptake could be detected. In order to investigate the actual uptake pathway into HeLa cells, positively... 

Fig. 59 Synthetic strategy for in-chain amino-functionalized, amphiphilic block copolymers with polystyrene and poly(ethylene glycol) blocks [PS-(NH2)- -PEO] via termination of the carbanionic polymerization with a benzyl-protected aminoglycidol unit (DBAG) [237b]. Numbers 1-5 refer to the compounds in the original article [237]...

Polystyrene-block-poly(L-lysine), polybutadiene-block-poly(L-lysine) [72], and block copolymers of polystyrene or polybutadiene with poly(carboxybenzoxy-L-lysine) [73] were also synthesized by Gallot and coworkers and evidence for lamellar assembUes were presented. Polysaccharide-block-polypeptide rod-coil systems were obtained by polymerizing the IV-carboxyanhydrides of Y -benzyl-L-glutamate from the asparagine a-amino function of carbohydrate fractions of ovomucoid (a glycoprotein extracted from hen egg white). Lamellar assembUes in concentrated solutions and in... 

---