2-Chlorotrityl chloride resin. Studies on anchoring of Fmoc-amino acids and peptide cleavage.
The esterification of 2-chlorotrityl chloride resin with Fmoc-amino acids in the presence of DIEA is studied under various conditions. High esterification yields are obtained using 0.6 equiv. Fmoc-amino acid/mmol resin in DCM or DCE, in 25 min, at room temperature. The reaction proceeds without by product formation even in the case of Fmoc-Asn and Fmoc-Gln. The quantitative and easy cleavage of amino acids and peptides from 2-chlorotrityl resin, by using AcOH/TFE/DCM mixtures, is accomplished within 15-60 min at room temperature, while t-butyl type protecting groups remain unaffected. Under these exceptionally mild conditions 2-chlorotrityl cations generated during the cleavage of amino acids and peptides from resin do not attack the nucleophilic side chains of Trp, Met, and Tyr.
Barlos
K
K
Department of Chemistry, University of Patras, Greece.
Chatzi
O
O
Gatos
D
D
Stavropoulos
G
G
D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism*; D004951:Esterification; D005449:Fluorenes / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism*; D012116:Resins, Plant; D014320:Triphenylmethyl Compounds
D000596:Amino Acids; D005449:Fluorenes; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D010455:Peptides; D012116:Resins, Plant; D014320:Triphenylmethyl Compounds; C071065:2-chlorotrityl chloride