Arylgrupper

Arylgrupper, in English commonly called aryl groups, are substituent fragments derived from arenes by removal of a hydrogen atom. They function as attached aromatic moieties in a wide range of organic molecules. The most familiar example is the phenyl group (C6H5–). Other examples include naphthyl, anthryl, and various substituted arenes.

The aryl group is attached to the rest of the molecule via a carbon–carbon bond, usually at the ipso position of the ring. Aryl groups are based on sp2-hybridized carbons, are planar, and can participate in conjugation with adjacent pi systems. Substituents on the ring can modulate electronic and steric properties, making the aryl group either more activating or more deactivating toward further transformations.

In chemistry, aryl groups participate in a range of reactions, most notably carbon–carbon bond-forming cross-couplings such as Suzuki–Miyaura, Heck, and Sonogashira reactions, which enable construction of biaryl and polyaryl architectures. They can be installed by coupling reactions from aryl halides or from aryl boronic acids, among other methods. The presence of an aryl group often stabilizes carbanions and reactive intermediates through conjugation and can influence the physical properties of molecules, including lipophilicity and aromatic stacking.

Applications span pharmaceuticals, agrochemicals, dyes, and organic materials, where aryl groups serve to modulate binding, spectra, and stability. They are a common design element in medicinal chemistry and materials science.