Ellman sulfonamide linker

Scheme 28 Activation and cleavage of the Ellman sulfonamide linker.

Scheme 2. Ellmans sulfonamide linker allowed the (DIPEA, N-ethyl-N,N-diisopropylamine DTT, synthesis of the acid- and base-labile glycopeptide dithiothreitol EDT, ethanedithiol GnHCI, thioester 6, which was used for the Native guanidinium hydrochloride NMP, N-methyl-...

Palomo JM, Lumbierres M, Waldmann H. Efficient solid-phase hpopeptide synthesis employing the Ellman sulfonamide linker. Angew. Chem. 2006 118 477-481. 

The Ellman sulfonamide linker is stable tmder acid or basic conditions. It can be selectively alkylated with haloacetonitriles, and then becomes susceptible to nucleophilic attack, leading to release of the peptide from the solid support (Scheme 5a)... 

However, classical cleavage with a solution of methanol and DMAP leads to significant racemerization of cysteine. An alternative approach was to release the peptide from the solid support using H-Cys(Far)-OMe as a nucleophile with microwave irradiation for 10 min. Peptide corresponding to N-Ras protein C-terminus 13 was synthesized using Ellman sulfonamide linker strategy as shown in Scheme 5b (dotted line) [59, 60]. 

Ellman s sulfonamide linker has also been used as the safety-catch-type linker for the synthesis of the glycodendrimer to enhance the interaction with the glycan receptors and lectins by the glycan multivalency effects (Scheme 16.9). Thus, the hexavalent a-man-nose introduced on the sohd-supported dendrimer 25 was activated for the nucleophihc... 

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