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.

中文翻译：

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基于 N-杂环卡宾的 Hauser-Kraus 环化催化平台

古老的 Hauser-Kraus 环化是生成含氧多环芳族化合物的有效且收敛的方法。尽管它应用于复杂的分子合成，但苛刻和强碱性的条件会限制其在更多功能化的分子环境中的应用。我们开发了第一个基于 N-杂环卡宾催化的催化 Hauser-Kraus 环化，该催化在较温和的条件下进行。我们展示了在存在几个功能组的情况下的转换范围。我们还提出了一种通过非规范 Breslow 中间体进行的环化的协调机制。