Ring-Opening Cyclization of Alkylidenecyclopropyl Ketones with Amines. An Efficient Synthesis of 2,3,4-Trisubstituted Pyrroles

An efficient synthesis of 2,3,4-trisubstituted pyrroles via intermolecular cyclization of alkylidenecyclopropyl ketones with amines was observed.
The addition of anhydrous MgSO4 improved the yields of the products 3. A possible mechanism involving the distal cleavage of the C−C bond
of cyclopropane ring was proposed.

通过分子内环化反应，将烷基乙烯基环丙酮与胺类物质反应，成功实现了2,3,4-三取代吡咯的高效合成。加入无水硫酸镁可显著提升产物3的收率。据此，提出了一种可能的机制，该机制涉及环丙烷环中C−C键的远端断裂。