Interrupted Nef Reaction of Cyclic Nitronates: Diastereoselective Access to Densely Substituted α-Chloronitroso Compounds
作者:Roman S. Malykhin、Yaroslav D. Boyko、Yulia V. Nelyubina、Sema L. Ioffe、Alexey Yu. Sukhorukov
DOI:10.1021/acs.joc.2c02281
日期:2022.12.16
The reaction of cyclic nitronic esters (isoxazoline- and 5,6-dihydro-4H-1,2-oxazine-N-oxides) with hydrochloric acid affords geminal chloronitroso compounds bearing a distant hydroxyl group. The reaction is usually diastereoselective, and in some cases stereodivergent formation of isomers at different temperatures is observed. The discovered process represents the first example of an interrupted Nef
环状硝酸酯(异恶唑啉-和 5,6-二氢-4 H -1,2-恶嗪-N-氧化物)与盐酸反应生成带有远羟基的孪生亚硝基氯化合物。该反应通常是非对映选择性的,并且在某些情况下观察到异构体在不同温度下的立体分歧形成。发现的过程代表了硝酸酯间断 Nef 反应的第一个例子。DFT 计算支持N , N的初始形成-双(氧)亚胺阳离子(Nef 反应中的关键中间体),被氯阴离子拦截,然后开环。证明了所得官能化氯亚硝基化合物在与环戊二烯的 Diels-Alder 反应中的合成效用。