Silylether

Silyl ethers are chemical compounds belonging to the group of ethers and containing a silicon atom and an alkoxy group, which are connected to each other by an atomic bonding. An important subset of the silyl enol ether, which are used as intermediates in organic synthesis chemistry use.

The basic structure is R1R2R3Si -O- R4, wherein R4 represents an alkyl or aryl group.

Frequently used silyl ethers are:

• Trimethylsilyl - derivatives ( TMS)
• Tert- butyldiphenylsilyl derivatives ( TBDPS )
• Tert-butyldimethylsilyl derivatives ( TBS / TBDMS )
• Triisopropylsilyl derivatives ( TIPS)

Silyl ethers are used as a protecting group in organic synthesis, which prevent the course of a multistep synthesis react with functional groups present reagents used. The special feature of protecting groups is the ability to add them reversible without great effort and secede again.

Education

There are some known methods for the formation of silyl ethers, two are particularly common:

• The reaction of the alcohol with a silyl chloride, and an amine at room temperature
• The reaction of the alcohol with a silyl triflate and an amine base at a low temperature

An example is the formation of silyl ethers using chlorotrimethylsilane.

Silyl enol ethers can be prepared analogously by the reaction of the carbonyl with silylchloride of aldehydes and ketones in the presence of an amine base can be obtained.

The cleavage can be effected by means of fluoride ion (eg tetrabutylammonium fluoride, hexafluorosilicic acid, or in a polar aprotic solvent such as THF).