(CAAC)Copper Catalysis Enables Regioselective Three-Component Carboboration of Terminal Alkynes

Cyclic(alkyl)(amino)carbene (CAAC) ligands are found to perturb regioselectivity of the copper-catalyzed carboboration of terminal alkynes, favoring the less commonly observed internal alkenylboron regiosomer through an alpha-selective borylcupration step. A variety of carbon electrophiles participate in the reaction, including ally! alcohol derivatives and alkyl halides. The method provides a straightforward and selective route to versatile trisubstituted alkenylboron compounds that are otherwise challenging to access.

Automated summary

Cyclic(alkyl)(amino)carbene (CAAC) ligands were found to affect the regioselectivity of copper-catalyzed carboboration of terminal alkynes, favoring the formation of internal alkenylboron regiosomers through alpha-selective borylcupration. Various carbon electrophiles, including ally! alcohol derivatives and alkyl halides, can participate in the reaction. This method provides a straightforward and selective route to access challenging trisubstituted alkenylboron compounds.