Water-medium C–H activation over a hydrophobic perfluoroalkane-decorated metal-organic framework platform

•Hydrophobic perfluoroalkane-decorated MOFs immobilize ultrafine Pd NPs.•High activity and regioselectivity in the direct C–H arylation of indoles were obtained in water.•The highly dispersed Pd NPs catalysts can be recovered and reused.

The use of water as reaction medium in the heterogeneous activation of C–H bonds has numerous advantages in terms of environmental benign, safety and cost efficiency impact. However, it is severely hampered because the reactants are difficult to dissolve in water and contact with the active sites of heterogeneous catalysts. Herein, we choose perfluoroalkane-functionalized mesoporous metal-organic framework (MOF) NU-1000 as a hydrophobic platform to encapsulate ultrafine palladium nanoparticles (Pd NPs) for C–H activation in water. The resultant Pd NPs stabilized by the perfluoroalkane exhibited high activity and regioselectivity in the direct C–H arylation of indoles in water. The introduction of perfluoroalkane chains into the mesoporous pores of NU-1000 provides hydrophobic surfaces to facilitate access of the reactants to the active sites to guarantee the high activity.

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