Department of Applied Chemistry, National Chiao-Tung University , 1001, Ta-Hseuh Road, Hsinchu 300-10, Taiwan.
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University , 100, Shih-Chuan First Road, Kaohsiung 807-08, Taiwan.
Org Lett. 2017 Jun 16;19(12):3103-3106. doi: 10.1021/acs.orglett.7b01224. Epub 2017 Jun 5.
A three-component cascade reaction of 2-aminobenzimidazole, aldehyde, and terminal alkyne has been explored for an efficient synthesis of benzimidazole-linked tetrasubstituted pyrroles. The reaction sequence involves the formation of propargylamine, insertion of a terminal alkyne, and a ring opening reaction followed by an intramolecular carbonylative cyclization under aerobic conditions. It represents a novel strategy to the construction of C═N, C═C, C═O bonds and a new five-membered 2-ketopyrrole ring. In this process, the reaction conditions are crucial and an attempt to elucidate the novel reaction pathway is well supported by X-ray crystallography.
已探索出一种由 2-氨基苯并咪唑、醛和末端炔烃组成的三组分级联反应，以高效合成苯并咪唑连接的四取代吡咯。该反应序列包括形成炔丙胺、插入末端炔烃、开环反应以及随后在有氧条件下进行的分子内羰基环化反应。这代表了构建 C=N、C=C、C=O 键和新型五元 2-酮吡咯环的新策略。在这个过程中，反应条件至关重要，尝试通过 X 射线晶体学阐明新的反应途径得到了很好的支持。
