Pd-Catalyzed Regioselective Arylation on the C-5 Position ofN-Aryl 1,2,3-Triazoles
摘要:
We herein report a highly efficient method for the arylation at the C-5 position of N-aryl 1,2,3-triazoles via a direct palladium catalyzed arylation reaction. The optimal reaction conditions required a combination of Pd(OAc)(2) and tris(o-tolyl)phosphine as catalyst, and Cs2CO3 as the base under inert atmosphere. A variety of C-5 substituted N-aryl 1,2,3-triazoles were prepared using these conditions with yields in the 70-88% range. Regioselective C-5 arylations were also performed on 1,4-disubstituted 1,2,3-triazoles. The regioselectivity in triazole substitution at the C-5 position was confirmed by single crystal XRD. In addition, computational investigations of key steps of the catalytic cycle using the density functional theory have provided a rationalization to the selective C-5 arylation of N-aryl 1,2,3-triazoles.
Design and applications of new phosphine-free tetradentate Pd-catalyst: Regioselective C–H activation on 1-substituted 1,2,3-triazoles and indoles(NH-Free)
作者:Sarma V. Markandeya、Ch. Renuka、Parvathi K. Lakshmi、A. Rajesh、Chidara Sridhar、Korupolu Raghu Babu
DOI:10.1080/00397911.2017.1381260
日期:2018.1.17
ABSTRACT This article describes the synthesis of a new phosphine free tetradentate Pd catalyst using dl-2,3-diaminopropionic acid. The complex was characterized by Mass, IR, and 1H NMR. The catalyst is air stable at room temperature and non-hygroscopic. Application of this new catalyst to regioselective C–H activation on 1-substituted 1,2,3-triazole and indoles with aryl iodides to get corresponding