The B-B bond adds across alkenes and alkynes to give the 1,2-diborylated alkanes and alkenes. Using various organorhodium or organoiridium catalysts, it can also be installed onto saturated hydrocarbons:
:CH(CH)CH + [pinB] → pinBH + CH(CH)Bpin
These reactions proceed via boryl complexes.
Bis(pinacolato)diboron can also be used as reducing agent for example in transition metal catalyzed hydrogenations of alkenes and alkynes.