A divergent cascade annulation has been developed using readily available vinyl azides and carbazates with a wide range of substituents. Vinyl azides were successfully applied as bifunctional partners to prepare aza-pyrimidinones via 6-ring closure with carbazates as well as to construct polyfunctionalized imidazoles via 5-ring closure with N-substituted carbazates. The aza-heterocycles were obtained with high levels of chemoselectivity and excellent yields.
Domino Approach for the Synthesis of Pyrrolo[1,2-α]pyrazine from Vinyl Azides
A domino synthesis of pyrrolo[1,2-alpha]pyrazine from 1H-2-pyrrolecarbaldehyde and readily synthesized vinyl azides was developed. This reaction proceeded under relatively mild conditions in the presence of base. Additionally, a possible mechanism for the entire sequence is proposed.