Alkylboranes oxidation/hydrolysis

Hydroboration-Oxidation An alkene reacts with BHsTHF or diborane to produce an alkylborane. Oxidation and hydrolysis of the alkylborane with hydrogen peroxide and base yield an alcohol (Section 8.6). 

An alternative procedure for oxidation to ketones involves treatment of the alkylborane with a quaternary ammonium perruthenate salt and an amine oxide186 (see Entry 6 in Scheme 4.9). Use of dibromoborane-dimethyl sulfide for hydroboration of terminal alkenes, followed by hydrolysis and Cr(VI) oxidation gives carboxylic acids.187... 

Oxidation of alkenylboranes with alkaline hydrogen peroxide is an important pathway to aldehydes and ketones (equation 13). Care must be taken to inhibit hydrolysis of the alkenylborane to the corresponding alkene and hence buffered conditions are frequently us. The reaction toloates the same wide range of functionality as the oxidation of alkylboranes. 

The addition of water is indirect in this process, and two reactions are involved. The first is the addition of a boron atom and hydrogen atom to the double bond, called hydrobo-ration the second is oxidation and hydrolysis of the alkylborane intermediate to an alcohol and boric acid. The anti-Markovnikov regiochemistry of the addition is illustrated by the hydroboration—oxidation of propene ... 

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