Bsmoc Protected Compounds
Bsmoc Protected Compounds
Bsmoc, 1,1-Dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl, is a base-sensitive amino protecting group for both solid and rapid continuous solution synthesis. Bsmoc does not suffer from the competitive or premature de-blocking observed with other systems because of steric hindrance (Carpino, L. A.; Ismail, M.; Truran, G. A.; Mansour, E. M. E.; Iguchi, S.; Ionescu, D.; El-Faham, A.; Riemer, C.; Warrass, R. The 1,1-Dioxobenzo[b]thiophene-2-ylmethyloxycarbonyl (Bsmoc) Amino-Protecting Group. J. Org. Chem., 1999, 64, 4324-4338). Bsmoc-protected amino acids are used in peptide synthesis. De-blocking of Bsmoc in peptide synthesis is done using a weak base such as insoluble piperazino silica as well as the polyamine, TAEA [tris-(2-aminomethyl)amine]. Deblocking with a weaker base or dilute base makes Bsmoc chemistry attractive compared to Fmoc chemistry, as base sensitive peptide units can be used without much contamination due to aminosuccinimide formation. Carbamate and ester derivatives of Bsmoc react readily with thiols via Micheal addition. Ureidopeptides can be prepared efficiently from the reaction of isocyanates derived from Bsmoc-alpha-amino acids with amino acid esters (Babu, V. V. S.; Sudarshan, N. S.; Naik, S. A. Synthesis of Ureidopeptides and Peptidyl Ureas Employing Bsmoc Chemistry. Int. J. Peptide Res. and Therap., 2008, 14, 105-112).
