Sharique Mohammed, Tambar Uttam K
The University of Texas Southwestern Medical Center 5323 Harry Hines Boulevard Dallas Texas 75390-9038 USA
Chem Sci. 2020 Jun 30;11(27):7239-7243. doi: 10.1039/d0sc03116j.
The venerable Hauser-Kraus annulation is an effective and convergent method for generating oxygenated polycyclic aromatic compounds. Despite its application in complex molecule synthesis, the harsh and strongly basic conditions can limit its utility in more functionalized molecular settings. We have developed the first catalytic Hauser-Kraus annulation based on N-heterocyclic carbene catalysis that proceeds under milder conditions. We demonstrate the scope of the transformation in the presence of several functional groups. We also propose a concerted mechanism for the annulation that proceeds through a non-canonical Breslow intermediate.
著名的豪泽-克劳斯环化反应是生成氧化多环芳烃化合物的一种有效且收敛的方法。尽管它在复杂分子合成中有应用,但苛刻且强碱性的条件会限制其在更多官能化分子环境中的效用。我们开发了首个基于氮杂环卡宾催化的催化豪泽-克劳斯环化反应,该反应在更温和的条件下进行。我们展示了在存在多个官能团的情况下该转化反应的适用范围。我们还提出了一种通过非经典布雷斯洛中间体进行环化反应的协同机理。