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Borane–tetrahydrofuran is an adduct derived from borane and tetrahydrofuran (THF). These solutions, which are colorless, are used for reductions and hydroboration, reactions that are useful in synthesis of organic compounds. A common alternative to BHF•THF is borane–dimethylsulfide, which has a longer shelf life and effects similar ...
Hydroboration–oxidation reaction is a two-step hydration reaction that converts an alkene into an alcohol. [1] The process results in the syn addition of a hydrogen and a hydroxyl group where the double bond had been.
The C-B bond has low polarity (electronegativity 2.55 for carbon and 2.04 for boron).Alkyl boron compounds are in general stable, though easily oxidized. Boron often forms electron-deficient compounds without a full octet, such as the triorganoboranes.
Mechanism of CBS reduction The first step of the mechanism involves the coordination of BH 3 to the nitrogen atom of the oxazaborolidine CBS catalyst 1 . This coordination serves to activate the BH 3 as a hydride donor and to enhance the Lewis acidity of the catalyst's endocyclic boron. [ 5 ]
Hydroboration proceeds via a four-membered transition state: the hydrogen and the boron atoms added on the same face of the double bond. Granted that the mechanism is concerted, the formation of the C-B bond proceeds slightly faster than the formation of the C-H bond.
A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH 3 ·O(CH 2) 4 or diethyl ether: BH 3 ·O(CH 3 CH 2) 2. Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model . [ 3 ]
Molecular species BH 3 is a very strong Lewis acid.It can be isolated in the form of various adducts, such as borane carbonyl, BH 3 (CO). [11]Molecular BH 3 is believed to be a reaction intermediate in the pyrolysis of diborane to produce higher boranes: [5]
Ball-and-stick model of the tetrahydroborate anion, [BH 4] −. Borohydride refers to the anion [B H 4] −, which is also called tetrahydridoborate, and its salts. [1] Borohydride or hydroborate is also the term used for compounds containing [BH 4−n X n] −, where n is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate [BH 3 (CN)] − and triethylborohydride or ...