V. Shagun, A. Medvedeva, A. Mareev
Mar 11, 2013
Citations
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Influential Citations
8
Citations
Journal
Tetrahedron
Abstract
Abstract The reaction of N -(2-pyridyl)-2-(trimethylsilylethynyl)-1,2-dihydropyridine-3,5-dicarbaldehyde self-assembling from three molecules of 3-trimethylsilyl-2-propyn-1-al and one molecule of 2-aminopyridine was monitored by 1 H NMR spectroscopy. It was shown that the aldehyde and amine ratio affects the concurrent trimerization of 3-trimethylsilyl-2-propyn-1-al into 4-(trimethylsilylethynyl)-4 H -pyran-3,5-dicarbaldehyde involving one molecule of water as a nucleophile. Two plausible mechanisms of 1,2-dihydropyridine and 4 H -pyran cascade assembling are proposed and analyzed by quantum chemical methods (MP2 and B3LYP). The transition states were found and the activation barriers were calculated for the key steps of the reactions. The potential energy surface (PES) analysis performed do suggests an alternative radical mechanism leading to 1,2-dihydropyridine and 4 H -pyran with significantly lower (by 10 kcal/mol) activation barriers at the limiting stages.