Categories: N-H Bond Formation >
Cleavage of carbamates
Protecting Groups
Recent Literature
A new mild method allows the removal of carbamates using TBAF in THF. Selectivity and mechanism are discussed.
U. Jacquemard, V. Beneteau, M. Lefoix, S. Routier, J.-Y. Merour, G. Coudert, Tetrahedron, 2004, 60,
10039-10047.
Cbz, Alloc, and methyl carbamate protected amines can be readily deprotected
by treatment with 2-mercaptoethanol in the presence of potassium phosphate in
N,N-dimethylacetamide at 75 °C. This nucleophilic deprotection protocol is
superior to the standard hydrogenolysis or Lewis acid-mediated deprotection
conditions for substrates bearing sensitive functionalities.
T. Scattolin, T. Gharbaoui, C.-y. Chen, Org. Lett.,
2022, 24, 3736-3740.
Diethylenetriamine is effective for a chemoselective direct cleavage of
unactivated carbamates and ureas without additional reagents and catalysts. The
method affords products in good yield and is not affected by air or moisture.
M. Noshita, Y. Shimizu, H. Morimoto, T. Ohshima, Org. Lett.,
2016, 18, 6062-6065.
An experimentally simple Microwave-assisted reductive alkylation of methyl
carbamate with a range of aldehydes provides, after basic work-up, structurally
diverse primary amines. This method is particularly amenable to high-throughput
synthesis.
F. Lehmann, M. Scobie, Synthesis, 2008,
1679-1681.
The condensation of readily available O-substituted carbamates with
2,5-dimethoxytetrahydrofuran gives N-alkoxycarbonyl pyrroles in good
yield. N-alkoxycarbonyl protection can endow pyrrole with distinct
reactivity in comparison with N-sulfonyl protection, for example, in a
pyrrole acylation protocol employing carboxylic acids with a sulfonic acid
anhydride activator.
J. L. Hann, C. L. Lyall, G. Kociok-Köhn, S. E. Lewis, J. Org. Chem., 2023, 88,
13584-13589.