Syntheses and properties of triborane(5)s possessing bulky diamino substituents on terminal boron atoms

The present communication reports the chemistry of three linear triborane(5) compounds possessing bulky diamino substituents on the terminal boron atoms. Fluorotriborane 2 was synthesized by a reaction of boryllithium and BF3 center dot OEt2. Halogen exchange reaction of 2 took place by a treatment with ClSiMe3 to give the corresponding chlorotriborane(5) 3. Addition of silver tetraarylborate to 3 in ether afforded a hydroxylated triborane(5) compound 5 probably via an unstable cationic boron intermediate 4.