Affiliation:
1. Laboratory of Quantum Chemical Modeling of Molecular Systems Irkutsk State University 1 Karl Marx St. 664003 Irkutsk Russian Federation
2. Siberian Branch of the Russian Academy of Sciences A. E. Favorsky Irkutsk Institute of Chemistry 1 Favorsky St. 664033 Irkutsk Russian Federation
Abstract
AbstractThe mechanisms of reactions between electron‐deficient acetylenes, specifically acylpyrrolylacetylenes, and 1‐pyrrolines were examined using a DFT B2PLYP‐D3/6‐311++G**//B3LYP/6‐31+G* approach. The study was focused on the interaction of 1‐phenyl‐3‐(1H‐pyrrol‐2‐yl) prop‐2‐yn‐1‐one with 5‐methyl‐3,4‐dihydro‐2H‐pyrrole, and was aimed at a clearer understanding of the reaction progress. The reaction pathway for the synthesis of a dipyrroloimidazole derivative comprising three five‐membered nitrogen‐containing heterocycles is compared to one typical for N‐substituted acylethynylpyrroles, which involves opening the pyrroline ring to form δ‐keto aminoenones. An explanation is presented for the high level of deuterium exchange during the reaction in deuterated methanol. Also, the impact of trace water in acetonitrile was assessed. A ring‐opening mechanism is proposed, involving the 1‐pyrroline molecule as a base. The photochemical isomerization process of the end product is also examined.
Funder
Ministry of Education and Science of the Russian Federation