alk1enyl

Alkenyl, sometimes encountered as alkenyl in literature, is a chemical term for a substituent derived from an alkene by removing one hydrogen atom, yielding a carbon–carbon double bond within the substituent. The alkenyl group is unsaturated, meaning it contains a C=C bond that can participate in addition reactions. In IUPAC nomenclature, alkenyl groups are treated as substituents and named by indicating the position of the double bond and the attachment point on the parent molecule.

Common examples include ethenyl (vinyl), -CH=CH2, and prop-2-en-1-yl (allyl), -CH2-CH=CH2, which attaches through the terminal methylene group. More generally, alkenyl groups vary by chain length and double-bond location.

Alkenyl groups are reactive centers in organic synthesis. They participate in electrophilic and radical additions, hydrogenation, halogenation, and polymerization of vinyl monomers. They can be installed into molecules by several methods, including cross-coupling reactions (for example, vinyl or alkenyl halides in Heck or Suzuki-type couplings), hydrofunctionalization of alkynes, and elimination or dehydration strategies from appropriate precursors.

Applications of alkenyl-substituted compounds include polymers (polyvinyl derivatives), pharmaceuticals, agrochemicals, and materials science. Their unsaturation enables functionalization and further transformations that are central to synthetic planning.

Notes: The form "alk1enyl" appears to be a typographical variant or error; the standard term is "alkenyl."