What is Hydroboration oxidation method?
Hydroboration–oxidation reaction is a two-step hydration reaction that converts an alkene into an alcohol. The process results in the syn addition of a hydrogen and a hydroxyl group where the double bond had been.
What is THF in Hydroboration oxidation?
In a solution in THF, borane exists as a loose Lewis acid-base complex. This allows boron to have an octet and makes the reagent more stable. The solution is commercially available in a 1 mol/L concentration in volumes from 25 to 800 mL. It is much more convenient to work with the solution than with a gas.
How is hydroboration regioselective?
We have already noted that the hydroboration of alkenes is regioselective; the boron atom adds preferentially to the less substituted carbon of an alkene. This is important because in Step 2 of the hydroboration-oxidation sequence, the boron atom is replaced by an OH group.
What is the function of THF?
THF (Tetrahydrofuran) is a stable compound with relatively low boiling point and excellent solvency. It is widely-used for dissolution and reaction of various substances. Also it is used as a starting material for the synthesis of poly(tetramethylene ether) glycol (PTMG), etc.
Why is Hydroboration-Oxidation?
The hydroboration mechanism has the elements of both hydrogenation and electrophilic addition and it is a stereospecific (syn addition), meaning that the hydroboration takes place on the same face of the double bond, this leads cis stereochemistry.
Is Hydroboration-oxidation regioselective?
A two-step reaction that converts an alkane double bond to a single bond, with regioselective and stereoselective addition of a hydroxyl group.
What is the Regiochemistry of hydroboration?
With hydroboration, we observe that the regiochemistry is “anti-Markovnikov” (H ends up bound to the most substituted carbon, B ends up attached to the least substituted carbon) and the stereoselectivity of the reaction is syn (both new bonds are formed on the same face of the alkene).
What is diisopinocampheylborane?
Diisopinocampheylborane is an organoborane that is useful for asymmetric synthesis. This colourless solid is the precursor to a range of related reagents. The compound was reported in 1961 by Zweifel and Brown in a pioneering demonstration of asymmetric synthesis using boranes.
What is the reaction between diisopinocampheylborane and methanol?
Diisopinocampheylborane reacts with methanol to give diisopinocampheylmethoxyborane, which in turn reacts with an allyl or crotyl Grignard reagent to give B -allyldiisopinocampheylborane. This can then undergo an asymmetric allylboration to give a chiral homologated alcohol, which is a useful building block in a chiral synthesis.
Which is more stable Diisopinocampheylchloroborane or trialkyl borane?
The chloride is reported to be more stable that the trialkyl boranes, it works well with aryl alkyl ketones and tert -butyl alkyl ketones. Diisopinocampheylchloroborane is often complementary with diisopinocampheylborane, where one provides the R enantiomer and the other the S, the enantioselectivity is typically very high.
How do you make Diisopinocampheylchloroborane?
Diisopinocampheylchloroborane (Ipc 2 BCl) is produced by treating diisopinocampheylborane with hydrogen chloride. The chloride is reported to be more stable that the trialkyl boranes, it works well with aryl alkyl ketones and tert -butyl alkyl ketones.