Facile synthesis of 3,5-diaryl-1,2,4-triazoles via copper-catalyzed domino nucleophilic substitution/oxidative cyclization using amidines or imidates as substrates

Two methods for the synthesis of 3,5-diaryl-1,2,4-triazoles, both domino reactions, are reported. The first procedure, the Cu(OTf)2-catalyzed reaction between two amidines using NaHCO3 as a base, 1,10-phenanthroline as an additive and K3[Fe(CN)6]/atmospheric oxygen as the oxidant, delivers 3,5-diaryl-1,2,4-triazoles with yields up to 68%. The second procedure for the synthesis of 3,5-diaryl-1,2,4-triazoles with yields up to 64% rests on the Cu(OTf)2-catalyzed reaction between two imidates and ammonium carbonate. This method features the formation of three bonds in a single synthetic step.