Catalyst-free and solvent-free hydroboration of alkynes

Abstract

The hydroboration of alkynes with pinacolborane (HBpin) under catalyst- and solvent-free conditions was demonstrated. Various alkynes were smoothly converted into alkenyl boronate esters in good to excellent yields at 110 °C. The gram-scale hydroboration of alkynes provided the corresponding boronates, which were further utilized for various chemical transformations and coupling reactions.