Dimethyl Sulfoxide Oxygen Donor‐Based Annulation of Ketones and Ammonium Persulfate: Regioselective Synthesis of 2,4‐disubstituted Oxazoles
作者:Zhongzhong Cao、Huifang Lv、Yufeng Liu、Zhiwen Nie、Haiping Liu、Tonglin Yang、Weiping Luo、Qiang Liu、Cancheng Guo
DOI:10.1002/adsc.201801671
日期:2019.4
An efficient protocol for the synthesis of substituted oxazoles via an annulation of ketones, DMSO, and ammonium is reported. DMSO is first found to serve as oxygen donor in annulation resulting in regioselective synthesis of 2,4‐disubstituted oxazoles. With the optimized conditions in hand, 22 examples of 2,4‐disubstituted oxazoles are obtained from readily available substrates. The protocol can be
报道了一种通过酮,DMSO和铵的环合反应合成取代的恶唑的有效方法。首先发现DMSO在环化中充当供氧体,导致2,4-二取代的恶唑的区域选择性合成。通过优化条件,可以从容易获得的底物中获得22个2,4-二取代的恶唑实例。该方案也可用于甲基酮和非甲基酮之间的交叉缩合反应,从而得到2,4,5-三取代的恶唑的4个实例。此外,我们已经成功地将该协议应用于克级,代表了良好的收率,这表明了该方法在有机合成中的潜在实用性。根据控制实验和文献,我们提出了合理的反应机理。