The carbene 2 and enetetramine 4 were synthesized from the pyrido-annulated triazolium salt 1 by deproton under strong base NaH and weak base K₂CO₃. The reaction performances of the carbene 2 and its enetetramine 4 with H₂O, S₈ and Se had also been studied, and the X-ray sin-gle-crystal analysis of the product 3 were studied. Reaction condition effect was tested. The Pd(II) complex of the triazolium carbene 2 turned out to be a powerful catalyst in direct α-arylation of caffeines with aryl bromide, which was comparable with or even superior to other well-established triazolylidenes already in the literature.

Key words: triazolium carbene, reaction property, palladium(II) complex, α-arylation