Domino Oxidative [Pd]-Catalysis: One-Pot Synthesis of Fluorenones Starting from Simple Benzylamines and Iodo Arenes

A domino [Pd]-catalysis for the efficient synthesis of fluorenones is presented. The overall reaction proceeds through the formation of a five membered Pd­(II)-cycle via a highly regioselective <i>ortho</i> C­(sp²)-H activation(s) of simple benzylamine that combines with external iodo arenes to give <i>ortho</i> arylated products. Significantly, the reaction further activates the C­(sp³)-H and C­(sp²)-H (intramolecular oxidative Heck coupling) bonds to give tricyclic imine systems. Then the usual water workup affords the fused tricyclic ketones (fluorenones). Remarkably, this one-pot operation enabled the effective construction of two C–C to three C–C bond