In organoboron chemistry, a carboryne is an unstable derivative of ortho-carborane with the formula B10C2H10.
The hydrogen atoms connected to carbon are removed by n-butyllithium in tetrahydrofuran and the resulting lithium dianion is reacted with bromine at 0 °C to form the bromo monoanion.
Heating the reaction mixture to 35 °C releases carboryne, which can subsequently be trapped with suitable dienes: such as anthracene (to afford a triptycene-like molecule) and furan in 10 to 25% chemical yield.
Carborynes react with alkynes to benzocarboranes [5][6] in an adaptation of the above described procedure.
Single crystal X-ray diffraction analysis of this compound shows considerable bond length alternation in the benzene ring (164.8 pm to 133.8 pm) ruling out aromaticity.