Directing Group-Free Formal Suzuki-Miyaura Coupling of Simple Ketones Enabled by Activation of Unstrained C-C Bonds.

The use of ketones as electrophiles to couple with arylboronic acid derivatives via C-C bond activation has become a significant progress in the area of Suzuki-Miyaura coupling (SMC) reaction, in which a permanent or temporary directing group is often required to promote the activation of the unstrained C-C bond via oxidative addition. Herein, we disclosed the first example of directing group free formal SMC reaction of simple ketones with arylboronates via Rh-catalyzed unstrained C-C bond activation. A wide range of simple ketones, including aryl alkyl ketones, diaryl ketones and aryl perfluoroalkyl ketones, can serve as electrophiles to participate in the SMC reaction with aryl or perfluoroalkyl as the leaving group. The key to the success of this reaction is by means of nucleophilic addition/β-carbon elimination sequence that can activate the unstrained ketone carbonyl C-C bond without the assistance of directing group.