Metyli

Metyli, or the methyl group, is the simplest alkyl substituent in organic chemistry. It is composed of a carbon atom bonded to three hydrogen atoms (CH3). When attached to a larger molecule, the metyli group replaces one hydrogen and can influence polarity, hydrophobicity, and reactivity.

In naming, metyli is the methyl substituent; the prefix "methyl-" is used in IUPAC nomenclature. The group is ubiquitous in organic chemistry, present in countless molecules from methane and methanol to toluene and many pharmaceuticals.

Production and introduction: Methyl groups are introduced to substrates via methylation reactions, using reagents such as methyl iodide, dimethyl sulfate, or other methylating agents; methods include electrophilic methylation, SN2 on methyl halides, and radical methylation under photochemical or catalytic conditions. The metyli group is often used as a protecting group or as a handle to modify physical properties of molecules.

Biological and ecological relevance: In biology, methylation refers to the addition of methyl groups to DNA, proteins, and other biomolecules. DNA methylation, typically at cytosine residues, is a major epigenetic mechanism regulating gene expression, development, and genome stability. S-adenosylmethionine commonly serves as the biological methyl donor.

Safety and environment: Many methyl compounds are flammable and potentially toxic. Methyl iodide is a hazardous, possibly carcinogenic substance; methanol is toxic if ingested; appropriate ventilation, containment, and waste handling are required.