Rh-Catalyzed Annulation of Benzoic Acids, Formaldehyde, and Malonates via ortho-Hydroarylation to Indanones

A three-component reaction from readily available low-cost materials of benzoic acids, formaldehyde, and malonates for the preparation of indanones by rhodium catalysis is reported. The annulation is initiated by an ortho-hydroarylation of benzoic acids, and a Lewis acid is not required. The solvent has a significant influence to the reaction, and 2-substituted or nonsubstituted indanones are obtained by the change of solvent.