Carbon polyboranes

While alkynes, nitriles, and isocyanides have long been known to insert a cage carbon into polyboranes (COMC (1982) 5.4.2.6.1 and 5.4.2.6.2), the use of aldehydes to insert a cage carbon was first reported by Bernd Brellochs in 1997 (Figure 5).86 Good yields of 10-vertex monocarbaboranes were obtained from B10H14 with KOH and many aldehydes and this reaction was thus coined the Brellochs reaction. 87... 

Diborane is not unique among the boron hydrides in its ability to form a carbonyl. High pressure reaction of either pentaborane-f / or tetra-borane-10 with carbon monoxide forms a substance which behaves like borane-carbonyl in its manner of decomposition. The formula of this polyborane-carbonyl has recently been established as OC B Hg (mp, — 114.5° bp, 59.6°) 41a). It reacts with trimethylamine without release of carbon monoxide. 

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