Wikipedia
Bis(pinacolato)diboron
Bis(pinacolato)diboron is a boron compound containing two pinacolato ligands. It has the formula [(CH)COB]; the pinacol groups are sometimes abbreviated as "pin", so the structure is sometimes represented as Bpin. It is a colourless solid that is soluble in organic solvents. It is a commercially available reagent for making pinacol boronic esters for organic synthesis.