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Lithium was deposited onto lithium chloride powder in a ∼5% weight/weight ratio. This material serves as a source of elemental lithium with benefits over bulk lithium alternatives including increased mass to facilitate measurement for small scale reactions and increased surface area. The Li/LiCl material is applied in the synthesis of a dilithiobutadienide that is transformed into a stannole with a drastic decrease in reaction time and notable increase in yield over commercial lithium granules.

The reactions of 9-phenyl-9-borafluorene with N H, P H, O H, and S H containing substrates were investigated. Protodeborylation reactions were observed for phenol, water, aniline, and para-bromothiophenol. In the water reaction, both O H bonds reacted with 9-phenyl-9-borafluorene to furnish the oxygen bridged diborane whereas only one of the N H bonds in aniline reacted. Phenylphosphine coordinated to the boron center to give an adduct that did not react further. The results were compared to the corresponding reactions with the same substrates and pentaphenylborole.

The reactivity of 9-phenyl-9-borafluorene with a series of 1,2-dipolar organic molecules is investigated, revealing that either adducts or seven-membered heterocycles are generated. A nitrile, imine, and isonitrile formed the corresponding coordination complexes that showed no evidence of conversion to ring expanded products. An aldehyde, ketone, and ketene inserted the C═O moiety into the endocyclic B–C bond resulting in BOC5 boracycles. Isocyanates inserted either C═N or C═O depending on the polarization of the substrate with the former being the only substrate to generate a BNC5 ring system. The results demonstrate the potential of 9-borafluorenes as effective reagents to generate seven-membered boracycles with a biphenyl backbone.