Methylation

When methylation in organic chemistry, the transfer of methyl groups in a chemical reaction of a molecule to another designated ( donor-acceptor principle). The transfer of alkyl groups are called general alkylation reagent alkylating agent.

Suitable methylating reagents are used, for example, methanol, dimethyl sulfate, diazomethane or methyl halides; the use of methyllithium is possible. Here, diazomethane is only suitable for the methylation of acidic compounds such as phenols, carboxylic acids and enols. In less acidic substrates, such as alcohols, the methylation may possibly be catalyzed by Lewis acids such as zinc chloride or silica gel.

Under transmethylation is the transfer of a methyl group of methyl donors in the C-, O- or N- atoms of biomolecules under the catalytic action of methyltransferase. This happens for example in the synthesis of creatine, choline or betaine. The most important methyl group supplier is the essential amino acid methionine, which occurs in the form of adenosylmethionine ( active methyl).