Complex polyfluoride additives in Fmoc-amino acid fluoride coupling processes. Enhanced reactivity and avoidance of stereomutation.
[reaction: see text] Isolated Fmoc amino acid fluorides have previously been shown to be among the most efficient reagents for peptide bond formation. Now, it has been found that anionic, polyhydrogen fluoride additives are capable of diverting many of the classical peptide coupling processes to acid fluoride couplings. Examples include the use of N-HBTU or N-HATU and the carbodiimide technique. As HF-containing species, these additives provide a more suitable medium for the coupling of systems that are sensitive to loss of configuration at the reactive carboxyl function.
Carpino
Louis A
LA
Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Ionescu
Dumitru
D
El-Faham
Ayman
A
Beyermann
Michael
M
Henklein
Peter
P
Hanay
Christiane
C
Wenschuh
Holger
H
Bienert
Michael
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D005449:Fluorenes / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
D000596:Amino Acids; D005449:Fluorenes; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D010455:Peptides; D005459:Fluorides