Trifluoromethyl-substituted Δ3-imidazolines: Synthesis and reactivity

Article abstract of DOI:10.1016/S0040-4039(97)00934-9

We describe the preparation of various 4-trifluoromethyl-substituted Δ³-imidazolines, which are precursors to amino acid-derived trifluoromethyl ketones. The imidazolines are prepared from α-silylimines and trifluoroacetonitrile by a 3+2 cycloaddition, and they can be hydrolyzed in weak acid to trifluoromethyl ketones. Additionally, we have identified several ring-opened compounds which result from treatment of the imidazolines with acid or base. Attempts to alkylate the imidazolines led to ring-opened products, so that the alkylation sequence ultimately produced N-alkylated amino acid-derived trifluoromethyl ketones.