Understanding the insertion reactions of CO₂, aldehyde and alkene into Cu-X (X = B, C, O) bonds

DFT calculations have been performed to study the relative preference of different unsaturated organic molecules (CO₂, PhCHO and styrene) for insertion into different Cu-X (X = B, C, O) bonds, which are competing processes in copper-catalyzed three-component bora-carboxylation reactions involving CO₂ and B₂pin₂. In this work, the variations in the insertion barriers and in the relative stability of the insertion products have been systematically analyzed and discussed in-depth. Our DFT calculations also allow us to make a prediction that when both aldehyde and styrene are present with CO₂ and B₂pin₂, styrene will undergo the three-component bora-carboxylation reaction rather than the aldehyde. (authors)