Organisch-Chemisches Instiut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
Chem Asian J. 2013 Aug;8(8):1786-94. doi: 10.1002/asia.201300324. Epub 2013 May 31.
The gold-catalyzed conversion of allyl-(ortho-alkynylphenyl)methyl ethers was investigated, and allylated isochromenes were obtained. An optimization of the catalysis conditions with respect to different phosphane and carbene ligands on gold, different counterions, and different solvents was conducted. Subsequently, the scope and limitations of this reaction were investigated with 21 substrates. The mechanistic studies show an allylic inversion, as supported by NMR data and an X-ray crystal structure analysis, as well as an intermolecular reaction, as determined by crossover experiments. There is no competition of protodeauration even in the presence of water. All these observations differ from other related conversions and clearly indicate product formation by a [3,3]sigmatropic rearrangement in the step forming the new C-C bond.
研究了金催化的烯丙基-(邻炔基苯基)甲基醚的转化，得到了烯丙基异噁唑。对金的不同膦和卡宾配体、不同抗衡离子和不同溶剂的催化条件进行了优化。随后，用 21 种底物对该反应的范围和限制进行了研究。机理研究表明存在烯丙基反转，这得到了 NMR 数据和 X 射线晶体结构分析的支持，以及通过交叉实验确定的分子间反应。即使存在水，也没有竞争的脱金反应。所有这些观察结果与其他相关转化不同，清楚地表明通过在形成新的 C-C 键的步骤中发生[3,3]西格玛重排形成产物。
