A magnetically recoverable copper-salen complex as a nano-catalytic system for amine protection via acetylation reaction using thioacetic acid

Amines are a beneficial class of compounds which are used as bioactive compounds, dyes and especially synthetic intermediates in the manufacture of many pharmaceutically active ingredients.1 Due to the presence of a lone electron pair, amines can act as nucleophile. Hence, because of their significant nucleophilicity, it is unavoidable to protect amine functional groups in the presence of other nucleophilic functionalities (e.g., OH, S, P, etc.) to exclude side reactions. 2 Recently, thioacids have attracted considerable interest in peptide science, as well as in native chemical ligiation. Moreover, Gopi et al. reported selective acetyl protection of amines using thioacetic acid in the presence of copper(II) acetate as catalyst.4 As the progress of our recent researches on environmentally friendly catalytic systems , we devised a nanocatalyst, taking advantage of the easy separation of magnetic nano-catalysts, the powerful complexing nature of Schiff bases, and the green character of chitosan, to heterogenize copper(II) ion to be applied in the acetyl protection of amines using thioacetic acid.

Keywords:

Thioacetic acid , Copper-salen complex , Magnetite , Nano catalyst , N-Acetylation reaction.