Vinyliodid

Vinyliodid, also known as vinyl iodide, is an organoiodine compound with the molecular formula C2H3I. It consists of the vinyl group CH2=CH– bonded to an iodine atom at the vinylic position. The compound has no geometric isomerism because the double bond bears two hydrogens on one carbon and a hydrogen and iodine on the other. In English literature it is typically called vinyl iodide, while vinyliodid appears in some non-English sources.

Physical and safety properties are typical of volatile halogenated alkenes. Vinyliodide is a colorless, flammable, and reactive liquid or gas at room temperature, with irritant properties. It reacts with air and moisture and can polymerize under light or in the presence of impurities. It should be handled in a well-ventilated fume hood with appropriate protective equipment, stored away from oxidizers and moisture, and kept under inert atmosphere if possible.

Preparation and availability are mainly through industrial or laboratory methods for vinyl halides. A common preparation route is the hydroiodination of acetylene, which adds iodine across the triple bond to yield vinyl iodide as a Markovnikov product. It can also be prepared from other vinylic precursors via halogenation or substitution reactions. Commercial supply is variable, and handling often requires controlled conditions due to its reactivity and lachrymatory nature.

Applications in organic synthesis center on the vinyl iodide unit as a versatile electrophilic partner. It serves as a substrate in palladium-catalyzed cross-coupling reactions (such as Suzuki, Negishi, and Stille couplings) to form substituted alkenes. It can also participate in other vinylation and coupling processes, enabling efficient construction of complex molecules. See also vinyl group and iodides.