Elemental-Sulfur-Incorporated Cyclizations of Pyrrolidines Leading to Thienopyrroles
journal contributionposted on 12.08.2020, 10:04 by Yuanyuan Yue, Huibin Shao, Zhixian Wang, Ke Wang, Le Wang, Kelei Zhuo, Jianming Liu
We report, herein, the synthesis of thieno[3,2-b]pyrroles from the direct oxidative [4 + 1] cyclization of 2-alkynyl pyrrolidines with elemental sulfur. This transformation likely originates from electrophilic attack at the β-position of pyrrolidine followed by an intramolecular thienannulation to deliver the desired product. Mechanistic investigation suggests that the present reaction involves the formation of dihydrothieno[3,2-b]pyrrole as an intermediate.