A palladium‐catalyzed [2+2+1] annulation among 3‐iodochromones, benzyl bromides, and norbornene has been developed. This annulation consists of a domino sequence involving Heck coupling/C(sp²)−H activation/C(sp³)−H activation, affording a variety of complex chromone derivatives bearing five contiguous tertiary carbon centers in up to 94% yield and 99:1 dr. Interestingly, the diastereoselectivity could be switched by fine‐tuning the solvent, in which endo isomer and exo isomer were obtained using mesitylene/CH₃CN and mesitylene, respectively.

中文翻译：

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钯催化的Heck偶联/ C（sp2）-H活化/ C（sp3）-H活化级联可实现分子复杂性的有效组装

在3-碘代色酮，苄基溴和降冰片烯中，钯催化了[2 + 2 + 1]环化反应。该环化过程由涉及Heck耦合/ C（sp ²）-H激活/ C（sp ³）-H激活的多米诺序列组成，提供了带有五个连续叔碳中心的多种复杂色酮衍生物，产率高达94％，99 ：1博士 有趣的是，可以通过微调溶剂来改变非对映选择性，其中分别使用均三甲苯/ CH ₃ CN和均三甲苯获得内异构体和外异构体。