What is TBS in organic chemistry?
Silyl ethers are a group of chemical compounds which contain a silicon atom covalently bonded to an alkoxy group. Common silyl ethers are: trimethylsilyl (TMS), tert-butyldiphenylsilyl (TBDPS), tert-butyldimethylsilyl (TBS/TBDMS) and triisopropylsilyl (TIPS).
Is TBS a protecting group?
The most popular and commercially available silyl-protective groups are trimethylsilyl (TMS), triethylsilyl (TES), tert-butyldimethylsilyl (TBS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS) as well as the diol-protective groups DTBS and TIPDS (Figure 1).
How do you Deprotect a TBS group?
Most common deprotection methods
- TMS groups are susceptible to cleavage upon treatment with HF-based reagents. Tetrabutylammonium fluoride (Bu4NF) in THF. Fluorosilicic acid (H2SiF6)
- Treatment with HCl in THF/water solution.
How do I Deprotect silyl?
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.
How do you remove silyl ether?
Removal of silyl ether protecting groups Reaction with acids or fluorides such as tetra-n-butylammonium fluoride removes the silyl group when protection is no longer needed. Larger substituents increase resistance to hydrolysis, but also make introduction of the silyl group more difficult.
Are silyl ethers good leaving groups?
An alkoxy group is a notoriously poor leaving group. But if you first protonate the ether to form an alkyloxonium ion, you have a much better leaving group. This is why silyl ethers make good protecting groups. They are exceptionally stable in base solution.
What is the purpose of a silyl ether?
Silyl ether groups, typically used to protect alcohol functions in organic synthesis, offer good control over the rate and mechanism of their cleavage through judicious choice of silicon substituents.
Is OTBS a good leaving group?
Let’s finish up by seeing some specific examples of Ts and Ms in action. As they contain a good leaving group, alkyl tosylates or mesylates can perform all of the substitution and elimination reactions of alkyl halides.
Which is the best suitable protecting group for alcoholic Oh?
silyl ethers
The most common protecting groups for alcohols are the silyl ethers. Here is the idea behind it. We take a silyl chloride, do a substitution using the alcohol as a nucleophile and then the alcohol converted into a silyl ether can be used in the presence of any strong base including the Grignard reagent.