Highly Efficient and Diastereoselective Construction of Trifluoromethyl‐Containing Spiro[pyrrolidin‐3,2′‐oxindole] by a Catalyst‐free Mutually Activated [3+2] Cycloaddition Reaction
作者:Hou‐Ze Gui、Yu‐Ning Gao、Yin Wei、Min Shi
DOI:10.1002/chem.201801971
日期:2018.7.17
catalyst‐free self‐catalyzed [3+2] cycloaddition reaction of isatin‐derived α‐(trifluoromethyl)imines with vinylpyridines is reported. The reaction offers a straightforward and atom‐economical procedure for the preparation of a series of 5′‐trifluoromethyl‐spiro[pyrrolidin‐3,2′‐oxindoles] in excellent yields and diastereoselectivities. The reaction mechanism has been investigated by control experiments
报道了靛红衍生的 α-(三氟甲基)亚胺与乙烯基吡啶的无催化剂自催化 [3+2] 环加成反应。该反应为制备一系列 5'-三氟甲基-螺环[吡咯烷-3,2'-羟吲哚]提供了一种简单且原子经济的方法,产率和非对映选择性都非常好。通过控制实验、p K a值的 DFT 计算和动力学曲线研究了反应机理,揭示了该反应的特点是靛红衍生的 α-(三氟甲基) 亚胺和乙烯基吡啶之间的相互激活以产生活性物质。