Organoboron compounds are indispensable intermediates in modern synthetic chemistry, yet efficient and general methods for their preparation from sterically hindered electrophiles remain limited. Herein, we report a sterically tolerant nickel-catalyzed borylation of aryl and vinyl triflates/acetate using bis(pinacolato)diboron (B2pin2) as the boron source. Building on our previous studies of nickel/B2pin2-promoted reductive transformations, we developed a catalytic system that enables the efficient conversion of structurally diverse aryl triflates, including sterically congested 2,6-disubstituted substrates, to the corresponding boronic esters under mild conditions. Extension of the strategy to vinyl triflates and inert vinyl acetates was achieved under modified conditions. Overall, this work provides a practical and cost-effective alternative to precious-metal-catalyzed methods and expands access to sterically hindered organoboron building blocks from readily available triflate precursors.
Gao et al. (Mon,) studied this question.