Mechanistic insights and computational design of Cu/M bimetallic synergistic catalysts for Suzuki-Miyaura coupling of arylboronic esters with alkyl halides

Carbonylative Suzuki-Miyura coupling reaction is one of the most efficient methods to synthetize ketones. In this work, the reaction mechanism of arylboronic esters with alkyl halides catalyzed by Cu/Mn synergistic catalysts has been studied by DFT calculation. The calculated results show that the whole reaction contains two cycles, one is the Cu-catalyzed transformation of Ar-Bneop to RO-Bneop, and the other is Mn-catalyzed Heck-Breslow cycle for alkyl halide carbonylation. At the last step, the final product aryl ketone is produced through the C-C crosscoupling between the two intermediates, which form from the above separate two cycles. For the title reaction, the [Mn(CO)5]- catalyzed the Heck-Breslow cycle belongs to SN2 mechanism, and Mn2(CO)10 catalyzed cycle is SET mechanism. In addition to [Mn(CO)5]-, the metal carbonyl anions with moderate even low nucleophilicity are suitable to co-catalyze the carbonylative Suzuki-Miyaura coupling with the Cu-carbene catalyst. Our calculation results are consistent with and provide explanations the experimental observations, as well as shed lights on further advancement of new bimetallic catalysts.

Automated summary

The reaction mechanism of arylboronic esters with alkyl halides catalyzed by Cu/Mn synergistic catalysts in carbonylative Suzuki-Miyura coupling reaction has been studied using DFT calculation. The reaction involves two cycles, one catalyzed by Cu for the transformation of Ar-Bneop to RO-Bneop, and the other catalyzed by Mn for the Heck-Breslow cycle of alkyl halide carbonylation. The final product, aryl ketone, is formed through C-C cross coupling between the intermediates formed in the two separate cycles. The results provide insights into the mechanism and potential for further development of new bimetallic catalysts.