One-pot synthesis of imidazolinium salts via the ring opening of tetrahydrofuran.

A new one-pot synthesis of C2-hydroxypropyl-substituted imidazolinium salts via the ring opening of tetrahydrofuran (THF) with N,N'-disubstituted diamines has been developed. Preliminary studies of the reaction mechanism suggest the CO-promoted oxidative ring opening of THF followed by Hg(ii)-mediated oxidation of an imidazolidine intermediate. These novel C2-substituted imidazolinium salts have shown to be active catalysts for the aza-Diels-Alder reactions.