A number of 2-(alkynylamino)-substituted heterocycles have been synthesized. These heterocycles rearrange in the presence of silver (I) and gold (I) salts to give novel 2 H- pyrimido [2, 1-b] benzoxazoles, 2 H-pyrimido [2, 1-b] benzothiazoles, and a 2 H-pyrimido [2, 1-b] benzoselenazole. Two of the the 2 H-pyrimido [2, 1-b] benzoxazoles were isolated in good yield. The kinetics of the silver tetrafluoroborate-catalyzed rearrangements of ...