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.
Department of Chemistry, University of Patras, Greece.
K
K
Barlos
O
O
Chatzi
D
D
Gatos
G
G
Stavropoulos
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