| Autor: |
Dubovtsev AY; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru., Zvereva VV; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru., Shcherbakov NV; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru., Dar'in DV; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru., Novikov AS; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru., Kukushkin VY; Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation. a.dubovtsev@spbu.ru v.kukushkin@spbu.ru and South Ural State University, 76, Lenin Av., 454080 Chelyabinsk, Russian Federation. |
| Abstrakt: |
Triflic acid (10 mol%) catalyzes the highly regioselective [2 + 2 + 2] cycloaddition between two cyanamides and one ynamide to grant the 2,4,6-triaminopyrimidine core. The developed synthetic method is effective for the preparation of a family of the diversely substituted heterocyclic products (30 examples; yields up to 94%). The synthesis can be easily scaled up and conducted in gram quantities. As demonstrated by the post-functionalizations involving the amino-substituents, the obtained heterocycles represent a useful platform for the construction of miscellaneous pyrimidine-based frameworks. The performed density functional theory calculations verified a particular role of H+, functioning as an electrophilic activator, in the regioselectivity of the cycloaddition. |
