Chloroformic acid 9H-fluoren-9-ylmethyl ester
9-Fluorenylmethyl chloroformate; 9-Fluorenylmethoxycarbonyl chloride; Fmoc-chloride
3D model (JSmol)
|Molar mass||258.70 g·mol−1|
|Melting point||62 to 64 °C (144 to 147 °F; 335 to 337 K)|
|S-phrases (outdated)||S26 S36/37/39 S45|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
The other common method for introducing the FMOC group is through 9-fluorenylmethylsuccinimidyl carbonate (FMOC-OSu), which may itself be obtained by the reaction of FMOC-Cl with the dicyclohexylammonium salt of N-hydroxysuccinimide.
It may be cleaved by bases, typically a solution of piperidine:
Because the fluorenyl group is highly fluorescent, certain UV-inactive compounds may be reacted to give the FMOC derivatives, suitable for analysis by reversed phase HPLC. Analytical uses of FMOC-Cl that do not use chromatography may be limited by the requirement that excess FMOC-Cl be removed before an analysis of fluorescence.
Amine Protection - Fluorenylmethyloxycarbonyl (Fmoc)
Common amine protection methods
- Fluorenylmethyloxycarbonyl chloride or 9-fluorenylmethyloxycarbonyl azide (itself made by reacting FMOC-Cl with sodium azide), sodium bicarbonate and aqueous dioxane
Common amine deprotection methods
- 20% Piperidine in dimethylformamide (Fmoc Group has an approximate half life of 6 seconds in this solution)
- Tetra-n-butylammonium fluoride in the presence of dimethylformamide
- Fmoc chloride at Sigma-Aldrich
- Carpino, Louis A.; Han, Grace Y. (1972). "9-Fluorenylmethoxycarbonyl amino-protecting group". The Journal of Organic Chemistry. 37 (22): 3404. doi:10.1021/jo00795a005.
- Yamada, Kazuhiko; Hashizume, Daisuke; Shimizu, Tadashi; Ohki, Shinobu; Yokoyama, Shigeyuki (2008). "A solid-state 17O NMR, X-ray, and quantum chemical study of N-α-Fmoc-protected amino acids". Journal of Molecular Structure. 888: 187. doi:10.1016/j.molstruc.2007.11.059.
- Paquet, A. (1982). "Introduction of 9-fluorenylmethyloxycarbonyl, trichloroethoxycarbonyl, and benzyloxycarbonyl amine protecting groups into O-unprotected hydroxyamino acids using succinimidyl carbonates". Canadian Journal of Chemistry. 60 (8): 976. doi:10.1139/v82-146. Archived from the original on 2012-07-26.
- J. Jones, Amino Acid and Peptide Synthesis, 2nd edn., Oxford University Press, 2002.
- Carpino, Louis A.; Han, Grace Y. "9-Fluorenylmethoxycarbonyl amino-protecting group". The Journal of Organic Chemistry. 37 (22): 3404–3409. doi:10.1021/jo00795a005.
- Wuts, P; Green, T (2006); "Greene's Protective Groups in Organic Synthesis"; DOI: 10.1002/9780470053485.
- Farrera-Sinfreu, Josep; Royo, Miriam; Albericio, Fernando (2002-10-21). "Undesired removal of the Fmoc group by the free ε-amino function of a lysine residue". Tetrahedron Letters. 43 (43): 7813–7815. doi:10.1016/S0040-4039(02)01605-2.