Advantages And Disadvantages Of Silylation

Advantages And Disadvantages Of Silylation

Advantages

i. Derivatives of alkylation are very stable ii. Some of these reactions can be done in aqueous solutions iii. Alkylation reagents are widely available iv. They are wither strong basic or acidic in nature.

Disadvantages

1. They are only limited to acid hydroxyl groups and amines

2. The reagents used are mostly toxic

Alkylating agents and how they act.

a. Boron trichloride in methanol or chloroethanol: an acidic hydrogen group undergoes esterification in the presence of boron trichloride an ester derivative. Acid BCl3

RCOOH + ClCH2CH2OH → RCOOCH2CH2Cl + H2O

b. Tetra–butyl–ammonium hydroxide (TBH): forms butyl ester with derivative or carboxylic acid that improves the retention time in the gas chromatography column. TBH ... Show more content on Helpwriting.net ...Reagents are sensitive to moisture

III. They also have odor and can be hazardous

IV. Acidic by–product is formed by the reagents which can damage the columns during Gas chromatography Acylating reagents used and their mechanism of action;

Reagents used in acylation are mostly halogenated or contain halogen compounds in their structures.

I. Fluorinated anhydrides react with amines, phenols, and alcohols to give highly volatile and stable derivative of the prior analyte to be used. Acid receptor or amines are needed to enhance the reaction.

II. Penta–fluoro–benzoyl Chloride can be used for stoically hindered functional groups. It is can also be used in the derivatization of secondary amines which are highly sensitive and alcohols. An acid by–product e.g. hydrochloric acid is formed during the process but can be neutralized with the use of sodium hydroxide. Chiral derivatization in Gas Chromatography

Special reagents are required for the derivatization of chiral compounds which are superimposable and grouped as enantiomers. The reaction of purely chiral reagents with enantiomeric compounds will proceed to the formation of a racemic mixture that is two derivative enantiomers of one compound and is separated using gas Chromatography to give separate diastereomers for each enantiomer. Chiral derivatization is in high demand due to research on chiral

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