Boosting photocatalytic cross-dehydrogenative coupling reaction by incorporating [RuII(bpy)3] into a radical metal-organic framework

Due to energy-efficient and green processes of photocatalysis, the visible-light-driven photocatalytic organic synthesis has developed greatly in the last decade. The well-known photocatalysts, RuII-polypyridyl complexes, have been extensively exploited in the synthesis of various chemicals. However, homogeneity of RuII-polypyridyl complexes makes their recycling difficult. Here, we show an effective strategy for boosting photocatalysis by incorporating [RuII(bpy)3] into a radical metal-organic framework (FJI-Y2). Recyclable photocatalyst FJI-Y2 can efficiently catalyze the cross-dehydrogenative coupling reactions of N-phenyltetrahydroisoquinoline derivatives with phosphite esters, forming medicinal α-aminoquinoline phosphonates. More importantly, the photocatalytic efficiency of FJI-Y2 is actually higher than its homogeneous counterpart [RuII(bpy)3]Cl2, because multiple intermolecular interactions between 1,4,5,8-naphthalenediimide radicals and [RuII(bpy)3] induce optimal photoinduced electron transfer process to expedite chemical conversion and recycling of catalysts. It is envisioned that MOFs containing radicals can be ideal platforms to incorporate more noble-metal photocatalysts for promoting photocatalysis.