Hydrolysis and methanolysis of the small closo-carbaboranes 1,5-dicarbapentaborane, 1,6-dicarbahexaborane, and 2,4-dicarbaheptaborane. The preparation of 1,3,5-triborapentane derivatives, (RO)2BCH2B(OR)CH2B(OR)2(R = Me or H)

Abstract

The order of reactivity toward methanol and water for three small closo-carbaboranes is B₃C₂^1,5H₅ > B₅C₂^2,4H₇ > B₄C₂^1,6H₆. The smallest carbaborane reacts rapidly with both reagents to form initially the triborapentane. (RO)₂BCH₂B(OR)CH₂B(OR)₂(R = Me or H). The other two carbaboranes give smaller cleavage products, B(OR)₃, BMe(OR)₂, and (RO)₂BCH₂B(OR)₂. The mass spectra of (MeO)₂BCH₂B(OMe)CH₂B(OMe)₂ and (MeO)₂BCH₂B(OMe)₂ are discussed.