Solid coupling reagents

Coupling Reactions with Solid Coupling Reagents. This procedure includes a step where J, is converted to structure 2 by heating the polymerization reaction mixture the procedure for the coupling step also applies to normal 1. 

DNA synthesizers operate on a principle similar to that of the Merrifield solid-phase peptide synthesizer (Section 26.8). In essence, a protected nucleotide is covalently bonded to a solid support, and one nucleotide at a time is added to the growing chain by the use of a coupling reagent. After the final nucleotide has been added, all the protecting groups are removed and the synthetic DNA is cleaved from the solid support. Five steps are needed ... 

Triisopropylbenzenesulfonyl)-3-nitro-1,2,4-triazole in the presence of 4-rtiorpholine pyridine-1-oxide was used with advantage as a coupling reagent for a solid-phase (p-alkoxybenzyl ester type resin) synthesis of peptides such as Leu-AIa-Gly-Val-OH or Leu-enkephalinamide (Tyr-Gly-Gly-Phe-Leu-NHs). The overall yield in the latter case was 70%, the purity of the peptide was 85-90%, and racemization was virtually zero.[38]... 

Scheme 13.7 Solid-phase synthesis of a glycopeptide from the homophilic recognition domain of epithelial Cadherin 1 using the new coupling reagent PfPyU.

COUPLING REAGENTS AND METHODS FOR SOLID-PHASE SYNTHESIS... 

LA Carpino, D Sadat-Aalaee, HG Chao, RH DeSelms. ((9-Fluorenylmethyl)oxy)car-bonyl (FMOC) amino acid fluorides. Convenient new peptide coupling reagents applicable to the FMOC/ferf-butyl strategy for solution and solid-phase syntheses. J Am Chem Soc 112, 9651, 1990. 

LA Carpino, A El-Faham. Tetramethylfluoroformidinium hexafluorophosphate a rapid-acting peptide coupling reagent for solution and solid phase peptide synthesis. J Am Chem Soc 117, 5401, 1995. 

LA Carpino, A El-Faham, F Albericio. Racemization studies during solid-phase peptide synthesis using azabenzotriazole-based coupling reagents. Tetrahedron Lett... 

The following coupling reagents are useful and some can be used in solid-phase and liquid-phase peptide... 

Many of these have been discussed in the previous sections. Additional information about specific coupling chemistries for proteins can be found in the protocols and discussion regarding solid phase reagents (Matson, 2000). 

The first version of solid-phase peptide synthesis (SPPS) to be developed used the /-Boc group as the amino-protecting group. It can be cleaved with relatively mild acidic treatment, and TFA is usually used. The original coupling reagent was dicyclohexylcar-... 

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