13984-59-3Relevant academic research and scientific papers
Carbon dioxide as a reversible amine-protecting agent in selective Michael additions and acylations
Peeters, Annelies,Ameloot, Rob,De Vos, Dirk E.
, p. 1550 - 1557 (2013)
Carbon dioxide can be used as a temporary protecting group for amines. A carbamic acid is formed reversibly when CO2 is bubbled through a solution of a sufficiently basic primary amine at room temperature and atmospheric pressure. This reaction is employed for the protection of the amine functionality in several reactions at room temperature where inter- or intramolecular selectivity is desired. The concept is demonstrated for the selective Michael additions to methyl acrylate of a normally less reactive sulfonamide in the presence of a strong amine nucleophile, or of a cyclic secondary amine in the presence of an aliphatic primary amine, or of a β-ketoester in the presence of amines. The selective acylation of an alcohol in the presence of an amine can be achieved under a CO2 atmosphere as well.
