School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, Guangxi University, Nanning, Guangxi 530004, China.
Org Biomol Chem. 2023 Apr 26;21(16):3411-3416. doi: 10.1039/d2ob02298b.
A facile metal-free synthesis of multi-substituted pyrimidines from readily available amidines and α,β-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.
本文报道了一种简便的无金属合成方法，可从易得的脒和α,β-不饱和酮合成多取代嘧啶。该合成涉及[3 + 3]环加成反应形成二氢嘧啶中间体，然后通过可见光激发的光氧化反应将其转化为嘧啶，而不是通常的过渡金属催化脱氢反应。研究了光氧化反应的机理。该工作提供了一种替代方法来合成嘧啶，具有操作简单、条件温和绿色、底物范围广泛的优点，避免了对过渡金属催化剂和强碱的依赖。
