Selective Divergent Synthesis of Indanols, Indanones, and Indenes via Acid-Mediated Cyclization of (<i>Z</i>)- and (<i>E</i>)-(2-Stilbenyl)methanols and Its Application for the Synthesis of Paucifloral F Derivatives
作者:Jira Jongcharoenkamol、Patsapon Chuathong、Yuka Amako、Masato Kono、Kasam Poonswat、Somsak Ruchirawat、Poonsakdi Ploypradith
DOI:10.1021/acs.joc.8b01921
日期:2018.11.2
structurally related to the natural product paucifloral F. At higher temperatures, 1,2- and 2,3-disubstituted indenes could be selectively prepared in good to excellent yields. On the other hand, the (Z)-stilbenes, under similar conditions (PTS-Si), did not give the indanols; only the 1,2-disubstituted indenes could be obtained. To gain further insights into the stereochemistry at C2–C3 for the (Z)-stilbenes
选自溴/碘苯甲醛衍生物,相应的(起始ž和( - )ë) - (2-芪)基甲醇可以在步骤2-5通过Pd-催化的交叉偶联反应制备(的Sonogashira和Heck反应),接着加入芳基锂/芳基格氏添加剂。对于(E)-斯蒂苯,随后在低温下使用固定在二氧化硅(PTS-Si)上的对-TsOH进行酸介导的环化反应,可得到2,3-反式在C2-C3处具有完全立体控制的-1-茚满醇。醇的进一步氧化提供了茚满酮,其在结构上与天然产物古朴的F有关。在较高的温度下,可以选择性地以良好至优异的产率制备1,2-和2,3-二取代的茚满。另一方面,在相似的条件下(PTS-Si),(Z)-苯乙烯基苯甲酸酯没有得到茚满醇;相反,(D)-Stilbenes没有得到茚满醇。只能得到1,2-二取代的茚。为了进一步了解(Z)-对甲磺胺在C2-C3的立体化学,采用氢化物或叠氮化物作为亲核试剂。相应的茚满产物在C2-C3处以顺式立体化学