Abstract The Michael addition-cyclodehydration of a 6-aminouracil and alkynone proceeds to give 5-deazapterin derivatives with total control of regiochemistry. This simple and facile cyclocondensation process is catalyzed by zinc (II) bromide or ytterbium (III) trifluoromethanesulfonate at 110 C, providing the heteroannulated products in up to 94% yield.