Methanetetraboroni and methanetriboronic esters

Octamethyl methanetetraboronate, [(MeO)2B]4C, has been prepared in > 100 g batches by the reaction of dimethoxyboron chloride and carbon tetrachloride with lithium in tetrahydrofuran. Analogous reactions have yielded the methanetriboronic esters [(MeO)2B]3CH, [(MeO)2B]3C-C6H5, and [(MeO)2B]3C-CH3. and the methanediboronic esters [(MeO)2B]2CH2 and [(MeO)2B]2CHC6H5. A preliminary survey of the properties of these compounds has been made.