Department of Chemistry , Indian Institute of Technology Bombay , Mumbai , 400076 , India.
J Org Chem. 2019 Mar 15;84(6):3158-3168. doi: 10.1021/acs.joc.8b03039. Epub 2019 Feb 25.
An expedient one-pot protocol for the synthesis of functionalized benzofuran containing fused and spiro-heterocycles has been accomplished by the modified Hauser-Kraus (HK) annulation of sulfonylphthalide with o-hydroxychalcones and o-hydroxynitrostyrylisoxazoles. The multicascade process involves Michael addition, Dieckmann cyclization, and a series of cyclizations, eliminations, and rearrangements to deliver the fused and spiro-heterocyclic products. An unusual transformation of fused indenofuran to naphthoquinone, the classical HK adduct, unraveled a novel pathway for the synthesis unsymmetrical naphthoquinones.
一种由磺酰基邻苯二甲酰亚胺与邻羟基查尔酮和邻羟基硝代苯并恶唑的改进豪泽-克劳斯（HK）环合反应，实现了含融合和螺杂环的功能化苯并呋喃的简便一锅法合成。多步反应包括迈克尔加成、迪克曼环化以及一系列环化、消除和重排反应，以生成融合和螺杂环产物。融合茚并呋喃向萘醌（经典的 HK 加合物）的异常转化揭示了合成不对称萘醌的新途径。
