This review aims to look past tris(pentafluorophenyl)borane to its halogenated triarylborane siblings, to give a greater understanding as to how modification to their aryl rings can lead to improved reactivity.

The catalytic activity of tris(3,4,5-trifluorophenyl)borane has been explored in the 1,2-hydroboration reactions of unsaturated substrates.

The addition of the Grignard 3,4,5-Ar F MgBr to aluminum(III) chloride in ether generates the novel triarylalane Al(3,4,5-Ar F ) 3 ·OEt 2 . Attempts to synthesize this alane via transmetalation from the parent borane with trimethylaluminum gave a dimeric structure with bridging methyl groups, a product of partial transmetalation. On the other hand, the novel alane Al(2,3,4-Ar F ) 3 was synthesized from the parent borane and trimethylaluminum. Interestingly, the solid-state structure of Al(2,3,4-Ar F ) 3 shows an extended chain structure resulting from neighboring Al···F contacts. Al(3,4,5-Ar F ) 3 ·OEt 2 was then found to be an effective catalyst for the hydroboration of carbonyls, imines, and alkynes with pinacolborane.

The ability of alkali metal complexes bearing chiral BINOL-derived ligands to catalyse the enantioselective hydroboration of ketones was explored.

Bicyclic expanded ring carbenes show increased sterics compared to similar monocyclic derivatives. The enhancement is a consequence of an impacting methyl substituent.