Fig. 1: Counteranion-enabled regioselective anti-addition of alkynes.

A Exploring boron as a bioisosteric replacement for carbon in the ring. B Polysubstituted allylic alcohol-containing drugs. C Synthesis of boracycles via alkyne hydroboration. D Trans-Selective Chan alkyne reduction. E Chloride counteranion influence on Ru-catalyzed trans-hydrometallation. F Counteranion-enabled trans-selective hydroboration of alkynes.