The Heck reaction is a chemical process that allows for the formation of carbon-carbon bonds. It typically involves the coupling of an aryl halide with an alkene in the presence of a palladium catalyst and a base. This reaction is valuable in organic synthesis for creating complex molecules, particularly in the pharmaceutical and materials industries. In the Heck reaction, the palladium catalyst facilitates the exchange of the halide group on the aryl compound with the alkene, resulting in a new carbon-carbon bond. The reaction conditions can be adjusted to optimize yields and selectivity, making it a versatile tool for chemists.