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Org Biomol Chem
; 21(16): 3411-3416, 2023 Apr 26.
Article
in English
| MEDLINE
| ID: mdl-37013394
ABSTRACT
A facile metal-free synthesis of multi-substituted pyrimidines from readily available amidines and α,ß-unsaturated ketones is reported. The synthesis involved a [3 + 3] annulation to form a dihydropyrimidine intermediate, which was converted to pyrimidine through visible-light-enabled photo-oxidation rather than the usual transition-metal-catalyzed dehydrogenation. The mechanism of the photo-oxidation was studied. This work has provided an alternative approach to pyrimidines with the advantages of easy operation, and mild and green conditions with a broad scope of substrates, circumventing the dependence on transition-metal catalysts and strong bases.