DFT calculations reveal the origin of controllable synthesis of β-boronyl carbonyl compounds from Cu/Pd-cocatalyzed four-component borocarbonylation of vinylarenes

This paper shows a DFT-based comparative mechanistic study on the Cu/Pd-cocatalyzed four-component borocarbonylative reactions among vinylarenes, aryl halides/triflates, bis(pinacolato)diboron (B(2)pin(2)), and CO to rationalize the experimental observation that aryl iodides deliver beta-boryl ketones while aryl triflates afford beta-boryl vinyl esters. The divergence in reactivity caused by different starting materials (aryl halides/triflates) is attributed to the different formation rates of intermediates in the copper and palladium catalytic cycles. The strength of C(sp(2))-X (X = I, OTf) bond and the relative stabilities of reactive aryl and acyl palladium intermediates are mainly responsible for the different formation rates. The theoretical results would provide assistance in further designing the synthesis of beta-boryl carbonyl compounds using synergistic Cu-Pd catalysis.

Automated summary

This study presents a DFT-based comparative mechanistic study on the Cu/Pd-cocatalyzed four-component borocarbonylative reactions. The experimental observation that aryl iodides deliver beta-boryl ketones while aryl triflates afford beta-boryl vinyl esters is rationalized. The divergence in reactivity is attributed to the different formation rates of intermediates in the copper and palladium catalytic cycles.