A General Nickel-Catalyzed Method for C−H Bond Alkynylation of Heteroarenes Through Chelation Assistance
作者:Shrikant M. Khake、Vineeta Soni、Rajesh G. Gonnade、Benudhar Punji
DOI:10.1002/chem.201605306
日期:2017.2.24
A general nickel‐catalyzed method for the alkynylation of heteroarenes through monodentate chelation assistance is described. Many heterocycles, including indoles, pyrroles, imidazoles, and pyrazole, efficiently coupled with (triisopropylsilyl)alkynyl bromide, and synthetically important functional groups, such as halides, ether, nitrile, and nitro, are tolerated. Synthetic applicability of this Ni‐catalyzed
描述了一种通过单齿螯合辅助的镍催化杂芳烃烷基化的通用方法。可以耐受许多杂环,包括吲哚,吡咯,咪唑和吡唑,它们可以有效地与(三异丙基甲硅烷基)炔基溴化物以及合成上重要的官能团(例如卤化物,醚,腈和硝基)偶联。通过去除三异丙基甲硅烷基并进一步官能化为三唑基,苯并呋喃基和炔基芳烃衍生物,可以证明这种镍催化方法的合成适用性。吲哚炔基化的初步机理研究表明,该反应通过动力学相关的CH活化进行,并遵循两电子氧化还原途径。具有催化作用的Ni物种,即[(Phen)3 Ni] NiBr分离出4个(PheN = 1,10-菲咯啉)并对其结构进行了表征。