Synthesis of pyrano[2,3-<i>f</i>]chromen-2-ones <i>vs.</i> pyrano[3,2-<i>g</i>]chromen-2-ones through site controlled gold-catalyzed annulations
作者:Antonio Arcadi、Alessia Ciogli、Giancarlo Fabrizi、Andrea Fochetti、Roberta Franzini、Francesca Ghirga、Antonella Goggiamani、Antonia Iazzetti
DOI:10.1039/c9ob01695c
日期:——
Regioselective access to 10-substituted-2H,8H-pyrano[2,3-f]chromen-2-ones through the gold-catalyzed intramolecular hydroarylation of readily available 7-(prop-2-yn-1-yloxy)-2H-chromen-2-one derivatives at their C-8 congested position was investigated by tuning the electronic and steric properties of the ligand on the gold complex. On the other hand, the combination of the JohnPhosAu(MeCN)SbF6 catalyzed
通过容易获得的7-(prop-2-yn-1-yloxy)-的金催化的分子内氢芳基化反应,对10-取代的2 H,8 H-吡喃并[2,3- f ] chromen -2- one进行区域选择性的访问。通过调节金络合物上配体的电子和位阻性质,研究了其C-8拥挤位置的2 H-铬-2--2-酮衍生物。另一方面,JohnPhosAu(MeCN)SbF 6的组合催化8-碘-7-(prop-2-yn-1-yloxy)-2H-铬-2--2-酮衍生物的分子内氢芳基化反应,然后进行选择性钯/甲酸C–I还原允许排他形成2 H,8 H-吡喃并[3,2- g] chromen-2-one区域异构体。这两个协议的开发提供了探索这些新的吡喃香豆素衍生物的生物学活性所需的通用合成工具。