Fmoc-2-mercaptobenzothiazole, for the introduction of the Fmoc moiety free of side-reactions.
A double side-reaction, consisting in the formation of Fmoc-beta-Ala-OH and Fmoc-beta-Ala-AA-OH, during the preparation of Fmoc protected amino acids (Fmoc-AA-OH) with Fmoc-OSu is discussed. Furthermore, the new Fmoc-2-MBT reagent is proposed for avoiding these side-reactions as well as the formation of the Fmoc-dipeptides (Fmoc-AA-AA-OH) and even tripeptides, which is another important side-reaction when chloroformates such as Fmoc-Cl is used for the protection of the alpha-amino function of the amino acids.
Isidro-Llobet
Albert
A
Institute for Research in Biomedicine, Barcelona Science Park, University of Barcelona, Josep Samitier 1, 08028-Barcelona, Spain.
Just-Baringo
Xavier
X
Ewenson
Ariel
A
Alvarez
Mercedes
M
Albericio
Fernando
F
D000596:Amino Acids / Q000737:chemistry; D052160:Benzothiazoles / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005449:Fluorenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D014961:X-Ray Diffraction
D000596:Amino Acids; D052160:Benzothiazoles; D005449:Fluorenes; C526251:fluorenylmethoxycarbonyl-2-mercaptobenzothiazole; C005563:captax