Despite the existence of three competing reactions for propargyloxyoxindoles, we report a chemoselectivity switch between enantioselective propargyl [2,3]‐Wittig rearrangement and Conia‐ene‐type reactions, with suppression of the [1,2]‐Wittig‐type rearrangement. Using C1‐symmetric imidazolidine‐pyrroloimidazolone pyridine as the ligand and Ni(acac)2 as the Lewis acid, diverse 3‐hydroxy 3‐substituted oxindoles containing allenyl groups were obtained in up to 98% yield and 99% ee via asymmetric propargyl [2,3]‐Wittig rearrangement. In the presence of AgOTf‐Duanphos, chiral spiro dihydrofuran oxindoles were given in up to 98% yield and 91% ee through a Conia‐ene‐type reaction.

中文翻译：

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炔丙氧基吲哚对映选择性 [2,3]-Wittig 重排和 Conia-Ene 型反应之间的化学选择性转换


尽管炔丙氧基羟吲哚存在三种竞争反应，但我们报告了对映选择性炔丙基[2,3]-Wittig重排和Conia-ene型反应之间的化学选择性转换，并抑制了[1,2]-Wittig型重排。使用C1对称咪唑烷-吡咯并咪唑酮吡啶作为配体和Ni(acac)2作为路易斯酸，通过不对称炔丙基获得了多种含有丙二烯基的3-羟基3-取代羟吲哚，产率高达98％，ee率高达99％[2 ,3]-维蒂希重排。在 AgOTf-Duanphos 存在下，通过 Conia-ene 型反应得到手性螺二氢呋喃羟吲哚，产率高达 98%，ee 高达 91%。