Pd-NHC-Catalyzed Direct Arylation of 1,4-Disubstituted 1,2,3-Triazoles with Aryl Halides

A highly efficient method for the synthesis of unsymmetrical multi-substituted 1,2,3-triazoles via a direct Pd-NHC system catalyzed C(5)-arylation of 1,4-disubstituted triazoles, which are readily accessible via click chemistry has been developed. It is important to note that C?H bond functionalizations of 1,2,3-triazoles with a variety of differently substituted aryl iodides and bromides as electrophiles can be conveniently achieved through this catalytic system at significantly milder reaction temperatures of 100 degrees C under air.