The Vilsmeier reagents generated from tertiary and secondary aliphatic and aromatic amides and trifluoromethanesulfonic anhydride (Tf2O) reacted with different nucleophiles (ROH, RSH, RNH2) affording the relative iminium and amidinium salts. The former, stable at room temperature, were easily transformed into the corresponding esters or O-alkyl thioesters by treatment with OH− or SH−.
TF2O/Amide adducts: Versatile reagents for the synthesis of imidates and amidines / Stefano Sforza;Arnaldo Dossena;Roberto Corradini;Eliana Virgili;Rosangela Marchelli. - In: TETRAHEDRON LETTERS. - ISSN 0040-4039. - 39(1998), pp. 711-714. [10.1016/S0040-4039(97)10642-6]