Exchange Kinetics of Quinolinyl Ketones with Boronic Acids via Rhodium Catalyzed C-C Bond Activation

Abstract

Carbon-carbon σ bond activation is difficult due to the strength of the σ bond and the steric hindrance around the bond. Using a quinolinyl ketone system, activation can be achieved with a rhodium catalyst, allowing not only carbon-carbon σ bond activation, but also functionalization using boronic acids. The exchange of aryl substituents between quinolinyl ketones and boronic acids, proceeding through carbon-carbon σ bond activation, is the subject of a kinetic study. NMR and kinetic studies are used to determine the rate law of the reaction using ortho-fluoro quinolinyl ketone and 4-trifluoromethyl boronic acid. In addition, NMR studies are used to compare the rates of various aryl substituents of both boronic acids and quinolinyl ketones to ortho-fluoro quinolinyl ketone and 4-trifluoromethyl boronic acid exchange.