Categories: N-H Bond Formation >
Cleavage of carbamates
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.