[4+2]-Annulation of prop-2-ynylsulfonium salts and N-substituted pyrrole-2-carboxaldehydes: access to indolizines containing a thioether group†
Abstract
An efficient synthesis of indolizines with a thioether group is developed through employing [4+2]-annulation of N-substituted pyrrole-2-carboxaldehydes and prop-2-ynylsulfonium salts, forming a wide variety of target compounds with various substituents and functionalities in moderate to good yields. The success of this transformation makes it an alternative approach to previous protocols, and pharmaceutical and biomedical applications of the investigated compounds are expected with further development.