phenylmethyl

Phenylmethyl, commonly known as the benzyl group, is a substituent in organic chemistry with the formula C6H5-CH2-. It consists of a benzene ring attached to a methylene group, making it a benzylic substituent. The group is often written as Bn- or as -CH2-Ph. In systematic naming, phenylmethyl is used in some contexts, though benzyl is far more common.

The benzylic carbon is activated toward reactions such as oxidation, substitution, and radical processes because of resonance stabilization from the adjacent aromatic ring. As a substituent, the benzyl group is relatively hydrophobic and nonpolar. It is stable under many standard conditions but can be cleaved or transformed under strong oxidants, hydrogenolysis, or other specialized reagents.

Uses and derivatives: The benzyl group is widely used as a protecting group in organic synthesis. Benzyl carbamate (Cbz) protects amines, and benzyl ethers protect alcohols. Benzyl halides, such as benzyl chloride or benzyl bromide, are common reagents for introducing the benzyl group. Benzyl alcohol serves as a versatile solvent and intermediate, and benzylidene derivatives form acetals and related structures.

See also: Benzyl group; Toluene; Benzaldehyde; Acetophenone.