Contributions to the chemistry of boron. Part 160. A convenient synthesis of catecholatoborane and diborane

Abstract

Catecholatoborane is formed in high yield (> 75%) by ball milling NaBH₄ and 2,2′-o-phenylene-dioxybis(1,3,2-benzodioxaborole) in diethyl ether in the presence of small amounts of LiCl. It also results quantitatively from the first two components in diglyme (MeOCH₂CH₂OCH₂CH₂OMe), but cannot be separated from the solvent. The reaction between NaBH₄ and catecholatoborane or the o-phenylene compound in diglyme can also be used to prepare diborane in high yield.