Highly efficient tetranuclear ZnII2LnIII2 catalysts for the Friedel–Crafts alkylation of indoles and nitrostyrenes

We demonstrate for the first time the high efficacy of tetranuclear ZnII2LnIII2 coordination clusters (CCs) as catalysts for the Friedel–Crafts (FC) alkylation of indoles with a range of trans-?-nitrostyrenes. The reaction proceeds in good to excellent yields (76%–99%) at room temperature with catalyst loadings as low as 1.0 mol