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
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
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可见光促进的镍和有机染料助催化芳基卤化物、三氟甲磺酸酯和乙烯基溴与二乙氧基乙酸作为甲酰基当量的甲酰化反应
DOI：
10.1002/anie.201610108
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发表时间：
2017-02-01
影响因子：
16.6
通讯作者：
Wang, Wei
中科院分区：
文献类型：
--
作者：
Huang, He;Li, Xiangmin;Wang, Wei
报道了在镍和有机染料协同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的一种简单甲酰化反应。与广泛使用的钯催化甲酰化过程不同，该反应通过两步机理进行，首先是通过4CzIPN介导的光氧化还原反应由二乙氧基乙酸原位生成二乙氧基甲基自由基。然后，甲酰基自由基等价物与芳基卤化物、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，除了芳基溴化物外，反应性较低的芳基氯化物、三氟甲磺酸酯和乙烯基卤化物也可作为该过程的有效底物。由于该反应所涉及的温和条件能耐受大量的官能团，因此该过程可应用于多种芳香醛的高效制备。
A simple formylation reaction of aryl halides, aryl triflates, and vinyl bromides under 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 insitu generation of the diethoxymethyl radical from diethoxyacetic acid by a 4CzIPN-mediated photoredox reaction. The formyl-radical equivalent then undergoes nickel-catalyzed substitution reactions with aryl halides and triflates and vinyl bromides to form the corresponding aldehyde products. Significantly, besides aryl bromides, less reactive aryl chlorides and triflates and vinyl halides serve as effective substrates for this process. Since the mild conditions involved in this reaction tolerate a plethora of functional groups, the process can be applied to the efficient preparation of diverse aromatic aldehydes.