Arylgruppe

Arylgruppe, in English aryl group, is a functional group in organic chemistry consisting of an aryl ring attached to the rest of a molecule through a single covalent bond. It is formed by removing one hydrogen from an aromatic hydrocarbon. The most common aryl group is the phenyl group, C6H5–, derived from benzene. Other aryl groups arise from larger aromatic rings, such as naphthyl (from naphthalene) or more complex aryl fragments used in substituted forms like tolyl (methylphenyl) or anisyl (methoxyphenyl).

Properties and characteristics: Aryl groups retain the aromatic ring and are typically sp2-hybridized at the attachment carbon. They are planar and can participate in conjugation with adjacent pi systems, influencing the electronic and steric properties of the molecule. Substituents on the ring can donate or withdraw electron density, modifying reactivity and stability. The attachment via an aromatic carbon often restricts rotation relative to the rest of the molecule, contributing to rigidity in some compounds.

Nomenclature and reactions: In names, aryl substituents are indicated with the prefix aryl- or by specific names such as phenyl, naphthyl, tolyl, or anisyl. Aryl groups arise widely in synthesis and applications, acting as leaving groups, stabilizing moieties, or conduits for conjugation. They participate in reactions typical of aromatic systems, including electrophilic aromatic substitution, and in modern methods such as cross-coupling reactions (for example, Suzuki–Miyaura and Negishi) when paired with appropriate partners.

See also: Aryl ether, aryl halide, aromatic compounds.