The C2 arylated indoles are important building blocks of biologically active molecules which are found in many natural products and pharmaceuticals.Up to now,only rare reports describing the direct C-H arylation of indoles using heterogeneous palladium catalysts.1 Metal-organic frameworks (MOFs) have been emerging as very attractive heterogeneous catalysis materials due to their high surface area,porosity,and chemical tunability.2 So far,there are only a handful of MOF materials as host matrices to support metal NPs as catalysts for heterogeneous catalysis.Our recent research has focused on the catalysis of metal NPs under liquid phase conditions,wherein we found that the Pd NPs supported on MOFs had unique catalytic properties for versatile organic synthesis such as the direct C2 arylation of indoles with iodobenzene,1 Suzuki3 and Heck4 cross-coupling reactions,and dehalogenation of aryl clorides.