An efficient, general and practical synthesis of diverse 3, 4-dihydropyrazines, 6, 7-dihydro-[1, 2, 3] triazolopyrazines and 7, 8-dihydro-[1, 2, 3] triazolodiazepines through intramolecular 1, 3-dipolar cycloaddition from amino acid derived common intermediates with high yields is described. Moreover, one-pot access to optically active 3-aryl substituted 6, 7-dihydro-[1, 2, 3] triazolo [1, 5-a] pyrazines in the palladium–copper co-catalytic system has also been ...
