How to get rid of TBDMS?
How to get rid of TBDMS?
Various tert-butyldimethylsilyl ethers are easily removed in excellent yields by treatment with a catalytic amount of N-iodosuccinimide in methanol. This method allows a selective deprotection of TBDMS ethers of alcohols in the presence of TBDMS ethers of phenols.
Which bond formed during the cleavage of silyl ethers is one of the strongest known?
5. A Better Way To Do It: Silyl Ethers. The main advantage of silyl ethers is that they’re easily cleavable. The Si-F bond is unusually strong – even stronger than Si-O.
How do I get rid of tetrabutylammonium fluoride?
The NaF is easier to remove because its solubility in organic solvents are considerably less than TBAF. Try to use TBA+-BF4- which is soluble in methanol. The exchange of counter ion can be accomplished by dissolving TBAF in acetonitrile, followed by addition of an equimolar amount of silver tetrafluoroborate.
How do you Deprotect silyl ether?
Typical deprotection protocols for the removal of silyl ethers are acidic aqueous THF, or acidic methanol, alkaline aqueous solutions and sources of fluoride ion, most commonly tetra-n-butylammonium fluoride, TBAF, in various solvents.
Why are protecting groups needed?
Protecting groups are used in synthesis to temporarily mask the characteristic chemistry of a functional group because it interferes with another reaction. A good protecting group should be easy to put on, easy to remove and in high yielding reactions, and inert to the conditions of the reaction required.
Why ether formation is not a good option for protecting alcohols?
The problem, however, is that it is difficult to cleave off the ether group. Ethers are quite stable and in fact, they are used as a solvent for organolithium reactions.
How do I get rid of tetrabutylammonium bromide?
Dissolve the solid in Ethyl acetate and wash the organic layer with water to separate TBAB. After water wash dried the organic layer with anhydrous sodium sulfate and evaporate the organic layer under reduced pressure to get pure compound.
How to deprotect tert-butyldimethylsilyl (TBDMS)?
Various tert -butyldimethylsilyl (TBDMS) ethers as well as tert -butyldiphenylsilyl (TBDPS) ethers can be easily deprotected by employing a catalytic amount of acetyl chloride in dry MeOH in good yields. This mild and convenient method tolerates various other protecting groups and does not lead to acylated or chlorinated byproducts.
How to remove TBDMS ethers from phenols?
Various tert -butyldimethylsilyl ethers are easily removed in excellent yields by treatment with a catalytic amount of N -iodosuccinimide in methanol. This method allows a selective deprotection of TBDMS ethers of alcohols in the presence of TBDMS ethers of phenols.
How much HF(OTF)4 is required for deprotection of TBS ether?
Hf (OTf) 4 exhibits exceptionally high potency in desilylations. Since the amounts of Hf (OTf) 4 required for the deprotection of 1°, 2°, 3° alkyl and aryl tert -butyldimethylsilyl (TBS) ethers range from 0.05 mol% to 3 mol%, a regioselective deprotection can be achieved.
Is TBDMS more stable than trimethylsilyl ether?
TBDMS ether is more stable to hydrolysis than trimethylsilyl ether, but is still readily cleaved by a variety of selective conditions. The deprotection of TBDMS is usually under mild acidic conditions [AcOH/H2O/THF, 3:1:1, or BF3 Et2O/CHCl3, etc. ], or with a fluoride ion. Although…
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