Solid-phase-bound

Horn J, Michalek F, Tzschucke CC, Bannwarth W (2004) Non-Covalently Solid-Phase Bound Catalysts for Organic Synthesis. 242 43-75 Houseman BT, Mrksich M (2002) Model Systems for Studying Polyvalent Carbohydrate Binding Interactions. 218 1-44 Hricovinlova Z,see Petrus L (2001) 215 15-41... 

Streptavidin-single-stranded DNA covalent conjugates were described as the building blocks for assembling nanostructured scaffolds [31], The amount and type of biotinylated ligands were used to modulate the affinity of duplex formation between solid-phase-bound nucleic acid templates and DNA-streptavidin conjugates. This system has been proposed for the design of fine-tuned sequence detection systems. 

Today, multi-parallel synthesis lies at the forefront of organic and medicinal chemistry, and plays a major role in lead discovery and lead optimization programs in the pharmaceutical industry. The first solid-phase domino reactions were developed by Tietze and coworkers [6] using a domino Knoevenagel/hetero-Diels-Alder and a domino Knoevenagel/ene protocol. Reaction of solid-phase bound 1,3-dicarbonyl compounds such as 10-22 with aldehydes and enol ethers in the presence of piperidinium acetate led to the 1-oxa-1,3-butadiene 10-23, which underwent an intermolecular hetero-Diels-Alder reaction with the enol ethers to give the resin-bound products 10-24. Solvolysis with NaOMe afforded the desired dihydro-pyranes, 10-25 with over 90 % purity. Ene reactions have also been performed in a similar manner [7]. 

Scheme 5.3 Stepwise assembly of the solid-phase-bound heptasaccharide thioglycosides as glycosyl donors and DMTST as activator.29...

To examine the chemical behavior of these new ligands 48-50 in coordination chemistry, tricarbonyl complexes with manganese and rhenium were synthesized from [MnBr(CO)s] and [ReBrCCOls] as described earlier for the other heteroscorpionate ligands (Scheme 28). The purpose of these tricarbonyl complexes was to verify tripodal binding of the solid-bound ligand. The protected OH linker in 50 acts as model for the solid phase bound ligand. 

Solid-Phase Bound Catalysts Properties and Applications... 

From this discussion it becomes clear that the community of academic and industrial chemists sees great future prospects particularly for solid-phase bound transition metal catalysts despite the fact that it is a very young field and that not all expectations have been fulfilled so far. A major problem is that transition metals are often not bound irreversibly, and their complexes are not as stable as they were... 

I 4 Solid-Phase Bound Catalysts Properties and Applications 4.3.1.1 Oxidation of Alcohols... 

Scheme 4.35 Multifunctional properties of solid-phase-bound catalysts.

Another example of solid phase DOS involves post-modification of the natural product macrolide antibiotic erythromycin (34) [77]. Erythromycin was first converted to analogue 32 which resembles a third generation macrolide antibiotic with high activity against resistant strains (ABT-773, 35), but is attached to solid phase-bound amino acids by reductive amination. Two further reductive amination steps and cleavage from solid support form a library of compounds of type 33 (Fig. 10). 

Free radicals generated by zinc and alkyl iodides easily add to oxime ethers (e.g. 106, equation 75), providing good yield of corresponding hydroxylamines 107. This reaction has also been performed in solid-phase bound oxime ethers. ... 

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