title: A mild removal of Fmoc group using sodium azide.
abstract: A mild method for effectively removing the fluorenylmethoxycarbonyl (Fmoc) group using sodium azide was developed. Without base, sodium azide completely deprotected N (α)-Fmoc-amino acids in hours. The solvent-dependent conditions were carefully studied and then optimized by screening different sodium azide amounts and reaction temperatures. A variety of Fmoc-protected amino acids containing residues masked with different protecting groups were efficiently and selectively deprotected by the optimized reaction. Finally, a biologically significant hexapeptide, angiotensin IV, was successfully synthesized by solid phase peptide synthesis using the developed sodium azide method for all Fmoc removals. The base-free condition provides a complement method for Fmoc deprotection in peptide chemistry and modern organic synthesis.
authors.affiliation: Department of Chemistry, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Chen
authors.forename: Basker
authors.initials: B
authors.lastname: Rajagopal
authors.forename: Xuan Yu
authors.initials: XY
authors.lastname: Liu
authors.forename: Kuan Lin
authors.initials: KL
authors.lastname: Chen
authors.forename: Yu-Chang
authors.initials: YC
authors.lastname: Tyan
authors.forename: Fui
authors.initials: F
authors.lastname: Lin
authors.forename: Po-Chiao
authors.initials: PC
authors.lastname: Lin
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000138:chemical synthesis; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D005449:Fluorenes / Q000737:chemistry*; D019476:Insect Proteins / Q000138:chemical synthesis; D012604:Scorpion Venoms / Q000138:chemical synthesis; D019810:Sodium Azide / Q000737:chemistry*; D060327:Solid-Phase Synthesis Techniques
chemical_list: D000596:Amino Acids; D005449:Fluorenes; D019476:Insect Proteins; C016456:N(alpha)-fluorenylmethyloxycarbonylamino acids; D012604:Scorpion Venoms; D000804:Angiotensin II; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-; D001224:Aspartic Acid; C075871:aspartimide; D019810:Sodium Azide