Palladium-Catalyzed Aryl C–H Olefination with Unactivated, Aliphatic Alkenes

Palladium-catalyzed
coupling between aryl halides and alkenes (Mizoroki–Heck
reaction) is one of the most popular reactions for synthesizing complex
organic molecules. The limited availability, problematic synthesis,
and higher cost of aryl halide precursors (or their equivalents) have
encouraged exploration of direct olefination of aryl carbon–hydrogen
(C–H) bonds (Fujiwara–Moritani reaction). Despite significant
progress, the restricted substrate scope, in particular noncompliance
of unactivated aliphatic olefins, has discouraged the use of this
greener alternative. Overcoming this serious limitation, we report
here a palladium-catalyzed chelation-assisted ortho C–H bond
olefination of phenylacetic acid derivatives with unactivated, aliphatic
alkenes in good to excellent yields with high regio- and stereoselectivities.
The versatility of this operationally simple method has been demonstrated
through drug diversification and sequential C–H olefination
for synthesizing divinylbenzene derivatives.

钯催化下芳基卤化物与烯烃的偶联反应（Mizoroki-Heck反应）是合成复杂有机分子的最受欢迎的反应之一。鉴于芳基卤化物前体（或其等效物）的供应有限、合成困难以及成本较高，这促使了对芳基碳-氢（C-H）键的直接烯基化的探索（Fujiwara-Moritani反应）。尽管取得了显著进展，但底物范围的限制，尤其是未活化脂肪族烯烃的不兼容性，使得这一更环保的替代方法的使用受到阻碍。为了克服这一严重限制，本研究报告了一种钯催化的螯合辅助正位C-H键烯基化反应，该反应以良好的至优异的产率和高区域选择性和立体选择性，将苯乙酸衍生物与未活化的脂肪族烯烃进行偶联。该操作简便方法的通用性已通过药物多样化以及用于合成二乙烯基苯衍生物的连续C-H烯基化反应得到验证。