Contribution To The Chemistry Of Boron .237. Bis(Benzo-1,3,2-Dioxaborolanyl)Oxide And 2-(O-Hydroxyphenoxy)-Benzo-1,3,2-Dioxa-Borolane. Precursors For The Synthesis Of Catecholborane (Benzo-1,3,2-Dioxaborolan)

The title compounds have been prepared from B(OH)(3) with catechol using different stoichiometries and were characterized by NMR spectroscopy and X-ray structure analysis. Bis(benzo-1,3,2-dioxoborolanyl)oxide, 3, has C-2 point group symmetry with a wide B-O-B bond angle (135.9 degrees) in contrast to the new catecholester of boric acid, 2-(o-hydroxyphenoxy)-benzo-1,3,2-dioxaborolane, 4, which shows an almost planar molecular structure. These molecules form infinite chains in the solid state. 2-Hydroxy-1,3,2-dioxaborolane 6 crystallizes as a OH ... O bridged dimer. 3 proved to be a good starting material for the preparation of catecholborane (C6H4O2)BH.