Université Paris-Saclay, UVSQ, CNRS, UMR 8180, Institut Lavoisier de Versailles, 78035 Versailles Cedex, France.
Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy.
Org Lett. 2021 Sep 17;23(18):7088-7093. doi: 10.1021/acs.orglett.1c02494. Epub 2021 Sep 1.
The first light-driven method for the α-trifluoromethoxylation of ketones is reported. Enol carbonates react with -trifluoromethoxy-4-cyano-pyridinium, using the photoredox catalyst 4-CzIPN under 456 nm irradiation, affording the α-trifluoromethoxy ketones in ≤50% isolated yield and complete chemoselectivity. As shown by 29 examples, the reaction is general and proceeds very rapidly under batch (1 h) and flow conditions (2 min). Diverse product manipulations demonstrate the synthetic potential of the disclosed method in accessing elusive trifluoromethoxylated bioactive ingredients.
本文报道了首例酮的光驱动α-三氟甲氧基化方法。烯醇碳酸酯在 456nm 光照下，使用光氧化还原催化剂 4-CzIPN 与 -三氟甲氧基-4-氰基吡啶反应，以≤50%的分离收率和完全的化学选择性得到α-三氟甲氧基酮。29 个实例表明，该反应具有普遍性，在分批（1 小时）和流动条件（2 分钟）下反应非常迅速。多种产物的操作进一步证明了所公开的方法在获得难以获得的三氟甲氧基化生物活性成分方面的合成潜力。
