Herein, we develop an efficient method for cobalt-catalyzed C(sp³)–H bond functionalization to synthesize indole derivatives. The highlight of this protocol is accomplished by sequential C–H activation. This “cobalt/organic oxidant” catalysis involves cheap Co(OAc)₂·4H₂O and ArSO₂NHOR and features mild conditions, low cost, and good functional group tolerance. Substrates containing primary or secondary inert C(sp³)–H bonds were well applied to this strategy. In addition, the isolated dehydrogenation byproduct indicated that the reaction might involve sequential C–H bond activation.

中文翻译：

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钴催化 C(sp3)-H 键官能化获得吲哚衍生物

在此，我们开发了一种钴催化的 C(sp ³ )-H 键官能化合成吲哚衍生物的有效方法。该协议的亮点是通过顺序 C-H 激活来完成的。这种“钴/有机氧化剂”催化涉及廉价的Co(OAc) ₂ ·4H ₂ O和ArSO ₂ NHOR，具有条件温和、成本低、官能团耐受性好的特点。含有初级或次级惰性 C(sp ³ )-H 键的底物很好地应用于该策略。此外，分离的脱氢副产物表明该反应可能涉及连续的 C-H 键活化。