Krylov I B, Paveliev S A, Shumakova N S, Syroeshkin M A, Shelimov B N, Nikishin G I, Terent'ev A O
N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences 47 Leninsky Prosp. Moscow 119991 Russian Federation
RSC Adv. 2018 Feb 5;8(11):5670-5677. doi: 10.1039/c7ra13587d. eCollection 2018 Feb 2.
Oxidative coupling of oxime and β-dicarbonyl compounds dominates in a β-dicarbonyl compound/oxime/Cu(ii)/-BuOOH system; in the absence of oxime, oxidative coupling of -BuOOH and a β-dicarbonyl compound (Kharasch peroxidation) takes place. The proposed conditions for oxidative coupling of oximes with dicarbonyl compounds require only catalytic amounts of copper salt and -BuOOH serves as a terminal oxidant. The C-O coupling reaction proceeds the formation of -butoxyl, -butylperoxyl and iminoxyl radicals. Apparently, -butylperoxyl radicals oxidize oxime into iminoxyl radical faster than they react with β-dicarbonyl compounds forming the Kharasch peroxidation product. Iminoxyl radicals are responsible for the formation of the target C-O coupling products; the yields are up to 77%.
在β-二羰基化合物/肟/Cu(ii)/叔丁基过氧化氢体系中，肟与β-二羰基化合物的氧化偶联反应占主导；在没有肟的情况下，叔丁基过氧化氢与β-二羰基化合物发生氧化偶联反应（卡拉施过氧化反应）。所提出的肟与二羰基化合物氧化偶联的条件仅需要催化量的铜盐，叔丁基过氧化氢用作终端氧化剂。C-O偶联反应通过形成叔丁氧基、叔丁基过氧基和亚胺氧基自由基进行。显然，叔丁基过氧基将肟氧化成亚胺氧基自由基的速度比它们与β-二羰基化合物反应形成卡拉施过氧化产物的速度快。亚胺氧基自由基负责形成目标C-O偶联产物；产率高达77%。
