Copper-Catalyzed Alkynylation of Benzylic C-H Bonds with Alkynylboronic Esters
We report a simple method for copper-catalyzed benzylic C-H alkynylation that uses alkynylboronic esters as nucleophilic coupling partners. The catalytic system is readily available and the reaction takes place under mild conditions. Different substrates for the C-H functionalization, as well as various alkynylboronic ester nucleophiles, were evaluated. Finally, three examples of enantioselective C-H alkynylations are presented.
