Organo-main-group chemistry (Boron)

Hydroboration - Oxidation

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A controlled oxidation is required to remove the boron atom and reveal the useful organic fragment. The simplest is alkaline hydrogen peroxide, which replaces the carbon-carbon bond with a carbon-oxygen bond to give an alcohol. The oxidation occurs by nucleophilic attack of the hydroperoxide ion on the empty orbital of the boron atom, followed by a migration of the alkyl chain from boron to oxygen. Hydroxide attacks boron to cleave the B-O-alkyl bond and release the alcohol.

(NOTE: Calculations showed that the alkyl migration and hydroxide attack occured in one step, so has been shown as such above.)

Boron goes backwards and forwards between planar neutral structures and anionic tetrahedral structures. This is typical of the organic chemistry of boron.

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X. Wang, Y. Li, Y. D. Wu, M. N. Paddon-Row, N. G. Rondan and K. N. Houk, J. Org. Chem., 1990, 55, 2601–2609.