Answer
Alkenes are the organic functional group that participate in the Heck reaction along with aryl halides. This reaction is a palladium-catalyzed carbon-carbon bond-forming reaction that involves the coupling of an aryl or vinyl halide with an alkene. The reaction proceeds via a catalytic cycle involving oxidative addition, migratory insertion, and reductive elimination, resulting in the formation of a new carbon-carbon bond between the aryl or vinyl group and the alkene.