Examples of borane in the following topics:
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- Boranes are chemical compounds of boron and hydrogen.
- Boranes are all colorless and diamagnetic.
- closo− There is no known neutral closo borane.
- Boranes can act as ligands in coordination compounds.
- Boranes can react to form hetero-boranes (e.g., carboranes or metalloboranes), clusters that contain boron and metal atoms.
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- Addition of hydroperoxide anion to the electrophilic borane generates a tetra-coordinate boron peroxide, having the general formula R3B-O-OH(-).
- The addition of borane, BH3, requires additional comment.
- Also, all three hydrogens in borane are potentially reactive, so that the alkyl borane product from the first addition may serve as the hydroboration reagent for two additional alkene molecules.
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- The resulting dialkyl borane is called disiamylborane, a contraction of di-secondary-isoamylborane (amyl is an old name for pentyl).
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- The mechanism of ether dealkylation proceeds via the formation of a complex between the boron center and the ether oxygen followed by the elimination of an alkyl bromide to yield a dibromo(organo)borane.
- The dibromo(organo)borane can then undergo hydrolysis to give a hydroxyl group, boric acid, and hydrogen bromide as products.
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- One way of accomplishing this is use an enantiomerically pure chiral alkyl borane reagent for the hydroboration step.
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- Alkenes, for example, may be converted to structurally similar alkanes, alcohols, alkyl halides, epoxides, glycols and boranes; cleaved to smaller aldehydes, ketones and carboxylic acids; and enlarged by carbocation and radical additions as well as cycloadditions.
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- Before leaving this topic it should be noted that diborane, B2H6, a gas that was used in ether solution to prepare alkyl boranes from alkenes, also reduces many carbonyl groups.
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- Remarkably, if this ketone is reduced by the bulky borane reagent, disiamylborane (C5H11)2BH, the diastereoselectivity is reversed, with isomer B being formed in 82% de.