Annulation of benzaldehydes with norbornenes toward indanones assisted by monodentate transient directing groups via double C-H activation

A novel synthetic strategy for indanones was established through a Pd-catalyzed direct annulation of benzaldehydes with norbornenes assisted by anilines as monodentate transient directing groups. The reaction proceeds smoothly under mild conditions and generates indanones with moderate to excellent yields. This protocol exhibits a broad functional group compatibility and high atom economy. Mechanistic investigations revealed that consecutive ortho aromatic C-H and carbonyl C-H activations of benzaldehydes are involved in the reaction.