Abstract
1,6-Dihydro-s-tetrazines such as 1, with a large variety of substituents in the 3- and 6-position of the heterocycle, have been synthesized, and due to their homoaromaticities and their potential reactivities, have aroused more and more interests (Sauer, J. 1,2,4,5-Tetrazines. In Comprehensive Heterocyclic Chemistry II; Boultou, A.J., Ed.; Elsevier: Oxford, UK, 1996; Vol. 6, 901; Neunhoeffer, H In Comprehensive Heterocyclic Chemistry I; Katritzky, A., Ed.; Pergamon Press Ltd.: Federal Republic of Germany, 1984; Vol. 3, 545).
Acknowledgment
We are indebted to Zhejiang Province Natural Foundation (No. 200016), Zhejiang Province Science and Technology Bureau (011101937) and National Natural Foundation (20272053) for financial support of this research.