Efficient one-pot synthesis of novel and diverse furo[2,3-d] pyrimidinediones and thioxofuro[2,3-d] pyrimidineones by the rhodium (II) pivalate-catalyzed reactions of cyclic diazo compounds.

The rhodium(II)-catalyzed reactions of cyclic diazo compounds derived from barbituric acid or thiobarbituric acid with arylacetylenes and styrenes were examined. These reactions provide a rapid synthetic route to the preparation of a variety of novel and diverse furo [2,3-d pyrimidine-2,4-diones, 2-thioxodihydrofuro [2,3-d pyrimidin-4-ones, dihydrofuro [2,3-d] pyrimidine-2,4-diones, and 2-thioxotetrahydrofuro [2,3-d] pyrimidin-4-ones.