9-Fluorenylmethyl carbamates
Fmoc-NR2, , FMOC amino, FMOC amine, FMOC amide
T. W. Green, P. G. M. Wuts,
Protective Groups in Organic
Synthesis,
Wiley-Interscience, New York, 1999, 503-507, 736-739.
Stability
| H2O: | pH < 1, 100°C | pH = 1, RT | pH = 4, RT | pH = 9, RT | pH = 12, RT | pH > 12, 100°C |
| Bases: | LDA | NEt3, Py | t-BuOK | Others: | DCC | SOCl2 |
| Nucleophiles: | RLi | RMgX | RCuLi | Enolates | NH3, RNH2 | NaOCH3 |
| Electrophiles: | RCOCl | RCHO | CH3I | Others: | :CCl2 | Bu3SnH |
| Reduction: | H2 / Ni | H2 / Rh | Zn / HCl | Na / NH3 | LiAlH4 | NaBH4 |
| Oxidation: | KMnO4 | OsO4 | CrO3 / Py | RCOOOH | I2, Br2, Cl2 | MnO2/CH2Cl2 |
Protection of Amino Groups
New, stable amino-protecting reagents, Boc-DMT and Fmoc-DMT, were prepared, and
found to be useful for the introduction of Boc and Fmoc groups into amines. Both
the reagents can protect various amines including amino acids in good yield in
aqueous media.
K. Hioki, M. Kinugasa, M. Kishimoto, M. Fujiwara, S. Tani, M. Kunishima,
Synthesis, 2006, 1931-1933.
Stable Fmoc-, Boc-, and Alloc-benzotriazoles react with various amino acids
including unprotected serine and glutamic acid, in the presence of triethylamine
at 20˚C to afford Fmoc-, Boc-, and Alloc-protected amino acids in very good
yields free of dipeptide and tripeptide impurities. Fmoc-, and Alloc-Gly-Gly-OH
dipeptides were prepared in excellent yields by N-acylation of glycylglycine.
T. S. Ibrahima, S. R. Tala, S. A. El-Feky, Z. K. Abdel-Samii, A. R. Katritzky, Synlett, 2011,
2013-2016.
Amino groups are selectively protected in good yields by reaction with O-alkyl
S-(pyridin-2-yl)carbonothiolates at room temperature in air. Even
substrates with multiple hydroxyl groups such as glucosamine are selectively
N-protected.
T. Suzuki, K. Tanaka III, Y. Hashimoto, N. Morita, O. Tamura, Synlett, 2020,
31,
899-902.
A simple and efficient protection procedure is general and regioselective for
the preparation of mono-N-Boc, N-Cbz, N-Fmoc or N-Alloc
aromatic amines in high yield without affecting aliphatic amino groups and other
functionalities.
V. Perron, S. Abbott, N. Moreau, D. Lee, C. Penney, B. Zacharie, Synthesis, 2009,
283-289.
Other Syntheses of Fmoc-Protected Amino Groups
Weakly basic carbon nucleophiles add efficiently to a Fmoc-protected N,O-acetal.
The new reactions shows the compatibility of the Fmoc protecting group with
moderately basic reaction conditions and should serve as a model for the
development of more efficient syntheses of Fmoc-protected amino acids.
A. E. Hartman, C. L. Brophy, J. A. Cupp, D. K. Hodge, T. J. Peelen, J. Org. Chem., 2009,
74, 3952-3954.
