C N and N C solution phase peptide synthesis using the N-acyl 4-nitrobenzenesulfonamide as protection of the carboxylic functionElectronic supplementary information (ESI) available: ESI features detailed analytical data of all compounds. Copies of 1H NMR and 13C NMR spectra of compounds 2, 4aj, 5ai, 7ai, 8j, 11j and of 1H NMR spectra of 9j and 10j. See DOI: 10.1039/c3ob40169c

• Main Authors: De Marco, Rosaria, Spinella, Mariagiovanna, De Lorenzo, Anna, Leggio, Antonella, Liguori, Angelo
• Format: Article
• Language: English
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/c3ob40169c

In this paper we describe a solution phase peptide synthesis strategy using the 4-nitrobenzenesulfonamido/ N -methyl-4-nitrobenzenesulfonamido group as a protecting/activating system of the carboxyl function. The 4-nitrobenzenesulfonamido group is stable during peptide chain elongation (Fmoc chemistry). The N -aminoacyl or N -dipeptidyl-4-nitrobenzensulfonamides, when activated by methylation, can be easily coupled with another amino acid or reconverted into the free-carboxyl function amino acids or peptides. This activatable protecting group allows both the C N and the N C direction solution phase peptide synthesis. We also verified that the absolute configuration at the chiral centers does not change during the coupling reactions. The N -acyl 4-nitrobenzenesulfonamides have been used as activatable protection of the carboxylic function in solution phase peptide synthesis for the obtainment of peptides both in the C N and in the N C direction.