A rapid and facile method for the general synthesis of 3-aryl substituted 4,5,6,7-tetrahydro[1,2,3]triazolo[1,5-a]pyrazines and their ring fused analogues.

We report a general and facile method that provides rapid entry into 3-aryl substituted 4,5,6,7-tetrahydro[1,2,3]triazolo[1,5-a]pyrazines and their ring fused analogues in one-pot under palladium-copper catalysis. The methodology utilises simple and easily available substrates of broad range. The applicability of this reaction for the synthesis of optically active products has been demonstrated. A plausible reaction mechanism has also been proposed.