A convenient synthesis of 2,4,5-triarylimidazoles catalyzed by Y(TFA)(3)

Yttrium(III) trifluoroacetate is used as efficient catalyst for reaction of benzil, aldehydes, and ammonium acetate under mild and solvent-free conditions to afford the corresponding 2,4,5-triarylimidazoles in high yields and short reaction time. Furthermore, the catalyst can be recovered conveniently and reused several times in the reaction without a significant loss of catalytic activity.