Transition-metal-free Chemoselective Oxidative C−C Coupling of the sp<sup>3</sup>C−H Bond of Oxindoles with Arenes and Addition to Alkene: Synthesis of 3-Aryl Oxindoles, and Benzofuro- and Indoloindoles
作者:Moh. Sattar、Vandana Rathore、Ch. Durga Prasad、Sangit Kumar
DOI:10.1002/asia.201601647
日期:2017.4.4
A transition‐metal (TM)‐free and halogen‐free NaOtBu‐mediated oxidative cross‐coupling between the sp3 C−H bond of oxindoles and sp2 C−H bond of nitroarenes has been developed to access 3‐aryl substituted and 3,3‐aryldisubstituted oxindoles in DMSO at room temperature in a short time. Interestingly, the sp3 C−H bond of oxindoles could also react with styrene under TM‐free conditions for the practical
过渡金属(TM)-free和无卤素的NaO吨卜介导的氧化的SP之间的交叉耦合3羟吲哚和SP的C-H键2硝基芳烃的C-H键已经发展到接入3-芳基取代的室温下,短时间内在DMSO中有3,3-芳基二取代的羟吲哚。有趣的是,在没有TM的条件下,羟吲哚的sp 3 C-H键也可以与苯乙烯反应,用于实际合成季铵3,3-二取代的羟吲哚。合成的3-氧吲哚也进一步转化为高级杂环,即苯并呋喃吲哚,吲哚吲哚和取代的吲哚。反应的机理实验表明,由sp 3形成阴离子中间体在DMSO中由叔丁醇碱形成的羟吲哚的CH键。在原位产生的碳负离子中添加硝基苯会导致DMSO中的3-(硝基苯基)氧杂吲哚基碳负离子,随后被DMSO氧化为3-(硝基-芳基)羟吲哚。