Enaminones in the Synthesis of New Polyaza Heterocycles

A simple and efficient method for the synthesis of larger polyaza heterocyclic structures 6a, 6b and 8 with 1,3-pyrimidine units has been developed, based on the reaction of enaminones with appropriate guanidines or carboxamidines under basic conditions. Using this procedure, several new, optically active polyaza heterocycles 10, 12 and 13 have been prepared in good yields, from enantiomerically pure Nα-Boc-L-arginine as guanidine reagents.