Computational Studies on Pd-Catalyzed Functionalization of Csp(2)-H Bonds Using a 1,2,3-Triazole Directing Group: Cyclization versus Substitution.
The Pd-catalyzed functionalization of Csp(2)-H bonds using a 1,2,3-triazole directing group has been investigated by density functional theory calculations at the B3LYP level. The results of these calculations showed that the substitution pathway was kinetically favored over the cyclization pathway for the N2-pyridine-1,2,3-triazole-4-carboxylic acid (TAPy)-directed functionalization of Csp(2)-H bonds, while the cyclization pathway was kinetically favored over the substitution pathway for the N1-aryl-1,2,3-triazole-4-carboxylic acid (TAA)-directed Csp(2)-H functionalization. The kinetic preference of the TAPy directing group for the substitution reaction can be attributed the reduced level of bond cleavage in the transition structure of the substitution step because the pyridine moiety of the TAPy directing group can act as a ligand for the Pd center.
Department of Chemistry, Jinan University , Huangpu Road West 601, Guangzhou, Guangdong 510632, P. R. China.
Juan
J
Li
Department of Chemistry, Jinan University , Huangpu Road West 601, Guangzhou, Guangdong 510632, P. R. China.
Lijuan
L
Du
Department of Chemistry, Jinan University , Huangpu Road West 601, Guangzhou, Guangdong 510632, P. R. China.
Honghong
H
Gu