Wang Xu, Yan An, Xiao Hua, Xiao Weiwei, Xu Liqing, Wang Dong
State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, Xinjiang, China.
Org Lett. 2025 Jun 6;27(22):5625-5631. doi: 10.1021/acs.orglett.5c01350. Epub 2025 May 22.
Despite extensive synthetic endeavors, achieving direct C3-H trifluoroacetylation in quinolines/pyridines continues to pose significant challenges. We report a protocol for direct C3-H trifluoroacetylation of quinolines and pyridines under transition-metal-free conditions. Readily accessible quinolines or pyridines serve as starting materials and undergo a dearomatization process to generate dihydroquinoline or dihydropyridine intermediates, which readily react with trifluoracetic anhydride. Subsequent acid-promoted dealkylative rearomatization delivers heteroaryl trifluoromethyl ketones. This tandem process is accomplished in a two-pot, one column process. The trifluoroacetyl group in the resulting heteroarenes can be readily transformed into a variety of functional groups.
尽管进行了广泛的合成尝试，但在喹啉/吡啶中实现直接C3-H三氟乙酰化仍然面临重大挑战。我们报道了一种在无过渡金属条件下对喹啉和吡啶进行直接C3-H三氟乙酰化的方法。易于获得的喹啉或吡啶用作起始原料，经过去芳构化过程生成二氢喹啉或二氢吡啶中间体，这些中间体很容易与三氟乙酸酐反应。随后的酸促进脱烷基再芳构化生成杂芳基三氟甲基酮。这个串联过程通过两锅一步柱法完成。所得杂芳烃中的三氟乙酰基可以很容易地转化为各种官能团。
