Synthesis of 9-borafluorene analogues featuring a three-dimensional 1,1′-bis(o-carborane) backbone.

The synthesis of [1,1′-bis(o-carboranyl)]boranes was achieved through the deprotonation of 1,1′-bis(o-carborane) reagents followed by salt metathesis with (iPr)2NBCl2. X-ray crystallography confirms planar central BC4 rings and Gutmann–Beckett studies reveal an increase in Lewis acidity at the boron center in comparison to their biphenyl congener, 9-borafluorene. [ABSTRACT FROM AUTHOR]