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This chemical reaction is useful in the organic synthesis of organic compounds. [1] Hydroboration produces organoborane compounds that react with a variety of reagents to produce useful compounds, such as alcohols, amines, or alkyl halides. The most widely known reaction of the organoboranes is oxidation to produce alcohols from alkenes.
A hydroboration reaction also takes place on alkynes. Again the mode of action is syn and secondary reaction products are aldehydes from terminal alkynes and ketones from internal alkynes. In order to prevent hydroboration across both the pi-bonds, a bulky borane like disiamyl (di-sec-iso-amyl) borane is used. [5]
Compounds of the type BR n (OR) 3-n are called borinic esters (n = 2), boronic esters (n = 1), and borates (n = 0). Boronic acids are key to the Suzuki reaction. Trimethyl borate, debatably not an organoboron compound, is an intermediate in sodium borohydride production.
The overall combined transformation of an aldehyde to an alkyne by this method is named after its developers, American chemists Elias James Corey and Philip L. Fuchs. The Corey–Fuchs reaction. By suitable choice of base, it is often possible to stop the reaction at the 1-bromoalkyne, a useful functional group for further transformation.
The alkyne zipper reaction requires a strong base, which can be generated from the reaction of potassium hydride and a diamine: [3] [1] Alkyne zipper reaction. The potassium 3-aminopropylamide deprotonates the less-substituted methylene adjacent to the alkyne group. [3] [1] Example mechanism for alkyne zipper reaction.
Disiamylborane (bis(1,2-dimethylpropyl)borane) is an organoborane with the formula [((CH 3) 2 CHCH(CH 3)) 2 BH] 2 (abbreviation: Sia 2 BH). It is a colorless waxy solid that is used in organic synthesis for hydroboration–oxidation reactions. Like most dialkyl boron hydrides, it has a dimeric structure with bridging hydrides.
The Fritsch–Buttenberg–Wiechell rearrangement, named for Paul Ernst Moritz Fritsch (1859–1913), Wilhelm Paul Buttenberg, and Heinrich G. Wiechell, is a chemical reaction whereby a 1,1-diaryl-2-bromo-alkene rearranges to a 1,2-diaryl-alkyne by reaction with a strong base such as an alkoxide.
The advantages of BMS over other borane reagents, such as borane-tetrahydrofuran, are its increased stability and higher solubility. [1] BMS is commercially available at much higher concentrations than its tetrahydrofuran counterpart (10 M) and does not require sodium borohydride as a stabilizer, which could result in undesired side reactions. [2]