Polymer-assisted solution phase PASP synthesis

One of the major innovations in combinatorial and medicinal chemistry in recent years aiming at efficient diversity-oriented synthesis has been the implementation of polymer reagents in polymer-assisted solution phase (PASP) synthesis. This contribution will present—following an introduction to the field—a concept of advanced polymer reagents based on reactive intermediates and active reactants that should extend the scope PASP synthesis significantly. Experimental procedures describing preparation and use of the novel polymer reagents are included. 

Polymer-Assisted Solution Phase (PASP) Synthesis... 

Fig. 1. Polymer-assisted solution phase (PASP) synthesis combines the merits of solution-phase chemistry with the advantages of facilitated phase separation by using polymer reagents (a) or scavenger resins (b).

Polymer-supported Synthetic Methods - Solid-phase Synthesis (SPS) and Polymer-assisted Solution-phase (PASP) Synthesis... 

The polymer-assisted solution-phase (PASP) synthesis of a 192-member group of 1,5-biaryl pyrazoles from 1,3-diketones and 4-hydrazinobenzoic acid as precursors has been reported <2004JC0332>. Condensation of aromatic or aliphatic esters with resin-supported sulfonamides 527, followed by cyclization with hydrazines, activation with trimethylsilyldiazomethane, and cleavage using amines, provided highly substituted, isomeric pyrazoles 528 and 529 (Scheme 63) <20000L2789>. 

Fig. B.14.1. Classical solid-phase synthesis (SPS) and polymer-assisted solution phase (PASP). In SPS (I) products are constructed step-wise, covalently attached to an insoluble polymer support. PASP...

Flynn, D. L. Devraj, R. V Naing, W. Parlow, J. J. Weidner, J. J. Yang, S. Polymer-Assisted Solution Phase (PASP) Chemical Library Synthesis, Med. Chem. Res. 1998, 8, 219. 

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-... 

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. 

II. Polymer-assisted solution phase synthesis (PASP synthesis)... 

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