Intramolecular Inverse Electron-Demand [4 + 2] Cycloadditions of Ynamides with Pyrimidines: Scope and Density Functional Theory Insights
2017
4-Aminopyridines are valuable scaffolds for the chemical industry in general, from life sciences to catalysis. We report herein a collection of structurally diverse polycyclic fused and spiro-4-aminopyridines that are prepared in only three steps from commercially available pyrimidines. The key step of this short sequence is a [4 + 2]/retro-[4 + 2] cycloaddition between a pyrimidine and an ynamide, which constitutes the first examples of ynamides behaving as electron-rich dienophiles in [4 + 2] cycloaddition reactions. In addition, running the ihDA/rDA reaction in continuous mode in superheated toluene, to overcome the limited scalability of MW reactions, results in a notable production increase compared to batch mode. Finally, density functional theory investigations shed light on the energetic and geometric requirements of the different steps of the ihDA/rDA sequence.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
116
References
14
Citations
NaN
KQI