Polymer assisted solution phase technique

An important breakthrough in that respect was the use of soHd-phase organic synthesis (SPOS) where the attachment of the substrate to an insoluble support allowed for easy workup (filtration) and for rapid generation of products via split-mix procedures [1,2]. An important subsequent development consisted of the immobihzation of reagents, scavengers and catalysts. This technique, coined polymer-assisted solution phase chemistry (PASP), allowed solution phase synthesis of compoimds, yet still enjoying the bene-... 

Scheme 5 Application of polymer-assisted solution phase (PASP) technique in Staudinger...

In this chapter we discuss the new speeding-up techniques, optimized during the last decade, such as solid-phase extraction, polymer-assisted solution-phase synthesis, microwave-assisted organic synthesis, and flow chemistry. The improvements obtained with these techniques are not limited to a subset of chemical reactions (e.g., the reported examples), but they are fully applicable to the entire set of chemistry involved in the synthetic drug discovery process. 

MAOS can also be coupled to polymer-assisted solution phase synthesis (PASP, see above). In 2005 a short review of the combination of these two techniques was published [22], gathering some representative examples of the recent literature. 

However, it was not until Merrifield developed a polystyrene matrix for peptide synthesis that a broad range of functionalized solid supports became available [91], leading to solid phase organic synthesis (SPOS) and eventually to polymer-assisted solution synthesis (PASS). Both of these techniques are heavily utilized by industry, especially for rapid library synthesis. 

Parlow JJ, Devraj RV, South MS (1999) Solution-phase chemical library synthesis using polymer-assisted purification techniques. Curr Opin Chem Biol 3 320-336... 

Matrix-assisted laser desorption ionization (MALDI), like ESI, is capable of ionizing and launching very large molecules (e.g, polysaccharides, synthetic polymers, peptides, and proteins) into the gas phase and is a major analytical tool for high-throughput proteomic studies.17,53 In many respects, MALDI is a complementary technique to ESI and both techniques are often applied to the same sample when determining protein identity. ESI produces macromolecular ions from solution, whereas MALDI produces them from the solid state. 

As described earlier in the section on bead or suspension polymers (Section 3.3.1.2), a solution of monomer(s) is prepared in water and then mixed into a low to medium viscosity non-volatile oil phase. In this process, which is often referred to as an inverse emulsion polymerisation technique, surfactants which promote the formation of water-in-oil emulsions are commonly used. These would usually be materials with an HLB (hydrophihc-lipophilic balance) value in the range 4—7, an example of which is sorbitan mono-oleate. In order to achieve the desired droplet particle size of a maximum around 1 pim prior to polymerisation, high shear homogenisers are used to assist the formation of such very small... 

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