Hypervalent λ³-iodanes have become a prominent tool for halofunctionalizations of alkenes. Despite many examples of asymmetric fluorinations reported lately, the corresponding enantioselective chlorination reactions using iodoresorcinol-based catalysts are significantly less developed, with only one example known to date. Here, we show how competing aromatic chlorination of the iodoarene catalyst is a significant obstacle in these transformations, hinting towards a conceptual issue with this well-established catalyst class for enantioselective chlorinations. Consequently, the reaction conditions and the catalyst design must be adapted to facilitate an effective chirality transfer. Hence, attention should be paid when selecting the oxidizing agent, the stoichiometry, and careful reaction analysis must be conducted to identify the factual catalytically active species.

高价 λ ³ -碘已成为烯烃卤代官能化的重要工具。尽管最近报道了许多不对称氟化的例子，但使用碘代间苯二酚基催化剂的相应对映选择性氯化反应的开发却明显较少，迄今为止仅已知一个例子。在这里，我们展示了碘芳烃催化剂的竞争性芳族氯化如何成为这些转化中的一个重大障碍，暗示了这种成熟的对映选择性氯化催化剂类别的概念问题。因此，必须调整反应条件和催化剂设计以促进有效的手性转移。因此，在选择氧化剂、化学计量时应注意，并且必须进行仔细的反应分析，以确定实际的催化活性物质。