Addition of HOAt dramatically improves the effectiveness of pentafluorophenyl-based coupling reagents

Authors
Klose, J El-Faham, A Henklein, P Carpino, LA Bienert, M
Citation
J. Klose et al., Addition of HOAt dramatically improves the effectiveness of pentafluorophenyl-based coupling reagents, TETRAHEDR L, 40(11), 1999, pp. 2045-2048
Citations number
15
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
11
Year of publication
1999
Pages
2045 - 2048
Database
ISI
SICI code
0040-4039(19990312)40:11<2045:AOHDIT>2.0.ZU;2-0
Abstract
In the course of comparing the effectiveness of several HOAt- and HOPfp-der ived coupling reagents by cyclization and segment condensation of model seq uences, using HPLC to follow the time course and to determine the outcome i n terms of oligomerization and epimerization, we found a striking improveme nt of the less effective HOPfp-based coupling reagent (HPyOPfp), both with regard to reaction rate and extent of epimerization, when HOAt was added. ( C) 1999 Elsevier Science Ltd. All rights reserved.