Dearomative cycloaddition is a crucial method for constructing three-dimensional (3D) complex molecules from simple precursors, but the difficulty in exciting many arenes limits the application of this method. Herein, we report a photocatalytic intermolecular dearomative [2 + 2]/[4 + 2] cycloaddition of phenanthrenes and naphthalenes with excited gem-difluoroalkenes for the synthesis of fused gem-difluorocyclobutanes and gem-difluorocyclohexanes. Previous dearomative cycloaddition reactions involving excited phenanthrenes and naphthalenes required electron-deficient substituents to lower their excited-state energies, allowing for energy-transfer catalysis to occur. Our strategy involves excited-state gem-difluoroalkenes undergoing dearomative cycloaddition reactions with ground-state phenanthrenes and naphthalenes, enabling it to tolerate not only electron-deficient arenes but also electron-neutral and electron-rich arenes.

中文翻译：

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菲和萘与激发的 gem-二氟烯烃的光催化分子间脱氢环加成反应


脱释环加成是从简单前体构建三维 （3D） 复杂分子的关键方法，但激发许多芳烃的困难限制了该方法的应用。在此，我们报道了菲和萘与激发的 gem-二氟烯烃的光催化分子间脱氢 [2 + 2]/[4 + 2] 环加成反应，用于合成熔融 gem-二氟环丁烷和 gem-二氟环己烷。以前涉及激发菲和萘的脱氢环加成反应需要缺电子取代基来降低其激发态能量，从而允许发生能量转移催化。我们的策略涉及激发态 gem-difluoroenes 与基态菲和萘进行脱酰胺环加成反应，使其不仅能够耐受缺电子的芳烃，还能耐受电子中性和富电子的芳烃。