4378-13-6Relevant articles and documents
General Fmoc-Based Solid-Phase Synthesis of Complex Depsipeptides Circumventing Problematic Fmoc Removal
Lobo-Ruiz, Ariadna,Tulla-Puche, Judit
supporting information, p. 183 - 192 (2020/01/24)
Development of an Fmoc-based solid-phase depsipeptide methodology has been hampered by base-promoted fragmentation and diketoperazine formation upon Fmoc group elimination. Such a strategy would be a useful tool given the number of commercially available Fmoc-protected residues. Herein we report that the addition of small percentages of organic acids to the Fmoc-removal cocktail proves effective to circumvent these drawbacks and most importantly, allowed the development of an exclusively solid-phase stepwise methodology to prepare a highly complex depsipeptide with multiple and consecutive esters bonds. Alongside, the optimal protecting group scheme for residue incorporation, which is not as straightforward as it is for traditional peptide synthesis, was explored. The developed stepwise strategy proved effective for the synthesis of a highly complex cyclodepsipeptide, being comparable to the yields obtained when using traditional combined chemistry approaches.
A mild removal of Fmoc group using sodium azide
Chen, Chun-Chi,Rajagopal, Basker,Liu, Xuan Yu,Chen, Kuan Lin,Tyan, Yu-Chang,Lin, Fui,Lin, Po-Chiao
, p. 367 - 374 (2014/03/21)
A mild method for effectively removing the fluorenylmethoxycarbonyl (Fmoc) group using sodium azide was developed. Without base, sodium azide completely deprotected Nα-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. Graphical Abstract: [Figure not available: see fulltext.]
Thermal cleavage of the Fmoc protection group
Hoeck, Stefan,Marti, Roger,Riedl, Rainer,Simeunovic, Marina
experimental part, p. 200 - 202 (2011/08/05)
The Fmoc protection group is among the most commonly used protection groups for the amino function. A fast method for the thermal deavage of this protection group under base-free conditions without the need for dibenzofulvene scavengers is presented. The advantages of this method include straightforward testability by means of a simple high-temperature NMR experiment, usually high yields, and good selectivity towards the BOC protection group and t-butyl ethers.
