Heck reaction is a palladium-catalyzed cross-coupling that forms what from aryl or vinyl halides and alkenes?

Heck reaction is a palladium-catalyzed cross-coupling that forms what from aryl or vinyl halides and alkenes?

• A. Alcohols
• B. Aldehydes
• C. Substituted alkanes
• D. Substituted alkenes

Answer: (D)

Heck reaction is a palladium-catalyzed cross-coupling that forms substituted alkenes by joining an aryl or vinyl halide to an alkene. The aryl or vinyl piece becomes attached across the carbon–carbon double bond, giving a new C=C bond with substituents derived from both partners. Mechanistically, palladium(0) undergoes oxidative addition to the halide, the alkene coordinates and inserts, and then β-hydride elimination releases the substituted alkene and regenerates the palladium catalyst with a base recharging the cycle. This sequence yields products that are substituted alkenes, not alcohols, aldehydes, or saturated alkanes.

Heck reaction is a palladium-catalyzed cross-coupling that forms substituted alkenes by joining an aryl or vinyl halide to an alkene. The aryl or vinyl piece becomes attached across the carbon–carbon double bond, giving a new C=C bond with substituents derived from both partners. Mechanistically, palladium(0) undergoes oxidative addition to the halide, the alkene coordinates and inserts, and then β-hydride elimination releases the substituted alkene and regenerates the palladium catalyst with a base recharging the cycle. This sequence yields products that are substituted alkenes, not alcohols, aldehydes, or saturated alkanes.