Au(I) and Au(III)-Catalyzed Mechanism of the Cyclization Reaction of 3-(Ethynylamino)-1,3-diphenylprop-2-en-1-one

The mechanisms of the cyclization reaction of 3-(ethynylamino)-1,3-diphenyl-2-en-1-one catalyzed by AuCl and AuCl 3 catalysts were studied using the density functional theory based on the M06 and B3LYP functionals combined with the 6-31G( d,p ), 6-311++G( d,p ), LANL2TZ) basis sets. The results show that the reaction can occur through one pathway containing four processes to yield the final product both with AuCl and AuCl 3 catalysts. The energy barrier of the rate-determining step of the reaction with AuCl, hydrogen transferring process, is 18.22 kJ mol –1 lower than that of the reaction with AuCl 3 . And the energy barrier of the catalysts depriving from the product with AuCl is 58.11 kJ mol –1 lower than that with AuCl 3 . These results indicate that the catalytic activity of AuCl is better than that of AuCl 3 for this type of reactions. The results of this study can be a theoretical reference in selecting a suitable catalyst for this type of reactions.