Solid-phase synthesis supports

Our library synthesis was carried out with a set of 27 tube-shaped solid phase synthesis support, called MicroTubes. These supports are prepared by radiation grafting of polystyrene ( — 350 pmol) onto polypropylene tubes, chemically functionalizing the polystyrene with aminomethyl groups to afford about 55 imol of amine per tube, inserting a reusable Rf ID tag into each tube, and heat-sealing the tube ends to prevent loss of the tag. The chemical conversion of all 36 aminomethyl tubes was carried out simultaneously using standard procedures with rink amide linker, each with —46 pmol of available amine per tube.1 2... 

Czarnik, A. W. (1998) Solid-phase synthesis supports are like solvents. Biotech-nol. Bioeng. (Comb. Chem.) 61, 77-79. 

Venkatesan H, Greenberg MM. Improved utility of photolabile solid-phase synthesis supports for the synthesis of oligonucleotides containing 3 -hy-droxyl termini. J Org Chem 61 525-529, 1996. 

The field of combinatorial chemistry covers a wide range of interdependent concepts and techniques as diverse as solid-phase synthesis, supported reagents, parallel homogeneous-phase chemistry, solid-phase extractions and adapted analytical methods. They were designed and developed both to address specific problems, libraries synthesis, and to help chemists in their everyday work. 

Developments in solid phase synthesis supports for the end of 1996 and much of 1997 are reviewed. Issues regarding support induced impurities and enhancing solid phase reaction rates are also discussed. 

E. C. Blossey and D. C. Neckers, Eds., Solid Phase Synthesis, Halsted, New York, 1975 P. Hodge and D. C. Sherrington, Eds., Polymer-Supported Reactions in Organic Synthesis, Wiley-Interscience, New York, 1980. A comprehensive review of polymeric protective groups by J. M. J. Frechet is included in this book. 

J.W. Labadie, Polymeric Supports for Solid Phase Synthesis, Curr Opin Chem Biol 2 346-352 1998. 

The adaptation of the Bischler-Napieralski reaction to solid-phase synthesis has been described independently by two different groups. Meutermans reported the transformation of Merrifield resin-bound phenylalanine derivatives 32 to dihydroisoquinolines 33 in the presence of POCI3. The products 34 were liberated from the support using mixtures of HF/p-cresol. In contrast, Kunzer conducted solid-phase Bischler-Napieralski reactions on a 2-hydroxyethyl polystyrene support using the aromatic ring of the substrate 35 as a point of attachment to the resin. The cyclized products 36 were cleaved from the support by reaction with i-butylamine or n-pentylamine to afford 37. 

First, they compared CSPs 1 and 3 prepared by the two-step solid-phase methodology with their commercially available counterparts (CSPs 2 and 4) obtained by direct reaction of the preformed selector with a silica support. Although no exact data characterizing the surface coverage density for these phases were reported, all of the CSPs separated all four racemates tested equally. These results shown in Table 3-3 subsequently led to the preparation of a series of dipeptide and tripeptide CSPs 5-10 using a similar synthetic approach. Although the majority of these phases exhibited selectivities lower or similar to those of selectors built around a single amino acid (Table 3-3), this study demonstrated that the solid-phase synthesis was a... 

Solid Phase Synthesis Versns Polymer-Supported Synthesis in Solution... 

Solid phase synthesis is a polymer-supported or solid-supported synthesis, i.e., stepwise construction of product molecules attached to an insoluble organic or inorganic polymer. 

Soluble support-based synthetic approaches offer the advantages of both homogeneous solution-phase chemistry (high reactivity, ease of analysis) and solid-phase synthesis (large excess of reagents, simple product isolation and purification) [98,99]. As a representative example, PEG, one of the most widely used soluble polymers, has good solubility in most organic solvents (i.e., dichloromethane, acetonitrile, dimethylformamide, and toluene), but it... 

Polymer supported xanthene derivatives have been used in the solid phase synthesis of 1-aminophosphinic acids, RCH(NH2)PH(0)0H, <%TL1647> and of C-terminal peptide amides <96JOC6326>. Xanthene units also feature in crown ethers <96JCS(P2)2091>, calixarenes <96JOC5670> and in a flexible template for a P-sheet nucleator <96JOC7408>. 

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