Su Zhenjie, Qian Siran, Xue Shuwen, Wang Cunde
School of Chemistry and Chemical Engineering, Yangzhou University, 180 Siwangting Street, Yangzhou 225002, P. R. China.
Org Biomol Chem. 2017 Sep 26;15(37):7878-7886. doi: 10.1039/c7ob01886j.
DBU-mediated [4 + 1] annulations of donor-acceptor cyclopropanes with carbon disulfide or thiourea to form 2-aminothiophene-3-carboxylate derivatives have been discovered. This reaction proceeds via the ring opening of donor-acceptor cyclopropanes to produce a 2-(iminomethylene)but-3-enoate intermediate, followed by the attack of an S-nucleophile for regioselective intermolecular nucleophilic addition, intramolecular S-nucleophilic addition, and final aromatization. A variety of functional groups could be tolerated under the reaction conditions.
已发现DBU介导的供体-受体环丙烷与二硫化碳或硫脲进行[4 + 1]环化反应以形成2-氨基噻吩-3-羧酸酯衍生物。该反应通过供体-受体环丙烷的开环生成2-(亚氨基亚甲基)丁-3-烯酸酯中间体，随后S-亲核试剂进行区域选择性分子间亲核加成、分子内S-亲核加成并最终芳构化。在该反应条件下，多种官能团均可兼容。
