Rhodium(III)-Catalyzed Direct Coupling of Quinoline-8-Carbaldehydes with (Het)Arylboronic Acids for the Synthesis of 8-Aryloylquinolines

Herein, we describe a method for the synthesis of aryl-(het)aryl ketones by Rh(III)-catalyzed direct coupling between quinoline-8-carbaldehydes and (het)arylboronic acids. The method has a broad substrate scope, a high functional group tolerance, and uses commercially available starting materials. Scale-up of the reaction and subsequent synthesis of tubulin polymerization inhibitor demonstrated its utilities. A plausible mechanism was proposed on the basis of the fact that a stable cycloacylrhodium intermediate complex could be used as catalyst, and the complex reacted stoichiometrically with (het)arylboronic acids.