Visible‐Light‐Promoted Nickel‐ and Organic‐Dye‐Cocatalyzed Formylation Reaction of Aryl Halides and Triflates and Vinyl Bromides with Diethoxyacetic Acid as a Formyl Equivalent
作者:He Huang、Xiangmin Li、Chenguang Yu、Yueteng Zhang、Patrick S. Mariano、Wei Wang
DOI:10.1002/anie.201610108
日期:2017.2
synergistic nickel‐ and organic‐dye‐mediated photoredox catalysis is reported. Distinct from widely used palladium‐catalyzed formylation processes, this reaction proceeds by a two‐step mechanistic sequence involving initial in situ generation of the diethoxymethyl radical from diethoxyacetic acid by a 4CzIPN‐mediated photoredox reaction. The formyl‐radical equivalent then undergoes nickel‐catalyzed substitution
据报道,在协同的镍和有机染料介导的光氧化还原催化下,芳基卤化物,芳基三氟甲磺酸酯和乙烯基溴化物发生了简单的甲酰化反应。与广泛使用的钯催化的甲酰化工艺不同,该反应通过两步机理进行,该过程涉及通过4CzIPN介导的光氧化还原反应从二乙氧基乙酸中原位生成二乙氧基甲基自由基。然后,甲酰基自由基与芳基卤化物,三氟甲磺酸酯和乙烯基溴化物进行镍催化的取代反应,形成相应的醛产物。重要的是,除了芳基溴化物之外,反应性较低的芳基氯和三氟甲磺酸酯和乙烯基卤化物可作为该方法的有效底物。由于该反应所涉及的温和条件可以耐受过多的官能团,