Catalytic asymmetric C3‐indolylation of N‐protected spiro‐epoxyoxindoles has been developed for the access of 3‐(3‐indolyl)‐oxindole methanols with excellent enantioselectivity (ee up to >99%). The widespread substrate scope and easily accessible Co(III)‐salen over 1,1′‐Spirobiindane‐7,7′‐diol phosphoric acid prove our condition to be more beneficial than the chiral Brønsted acid‐catalyzed reaction. Further, kinetic resolution of spiro‐epoxides is achieved in high enantiomeric excess under certain conditions. The detailed mechanistic study endorses that the feedback inhibition played a key role which restricts the dynamic kinetic resolution process. Besides it also revealed the S_N2′ mechanism for the Co(III)‐salen catalysed C3‐indolylation of spiro‐epoxyoxindoles.

中文翻译：

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Co（III）salen催化螺-环氧氧吲哚的对映选择性C3-吲哚化及其机理的研究

N保护的螺氧基环氧吲哚的催化不对称C3吲哚化已开发出来，可用于对映体选择性极好（ee高达99％以上）的3-（3-吲哚基）-吲哚甲醇。广泛的底物范围和容易获得的Co（III）-salen过度1,1'-螺二茚满-7,7'-二醇磷酸证明我们的条件为比手性溴更有益ø B酸催化反应。此外，在某些条件下，对映体过量时，可以实现螺环氧化物的动力学拆分。详细的机理研究表明，反馈抑制起着限制动态动力学拆分过程的关键作用。此外它还显示了S _NCo（III）-salen催化螺-环氧-氧吲哚的C3-吲哚化的2'机理。