vinylstannane

Vinylstannane is an organotin compound in which a vinyl group is bonded to tin through a carbon–tin bond. The general structure is R3Sn–CH=CH–R′, where R groups on tin are typically alkyl or aryl substituents; a common example is Bu3Sn–CH=CH2 (vinyltributyltin).

Preparation methods for vinylstannanes mainly rely on the hydrostannation of alkynes. Tributyltin hydride (Bu3SnH) adds across a carbon–carbon triple bond in a radical process to give vinylstannanes in anti-Markovnikov fashion. For terminal alkynes, this yields Bu3Sn–CH=CH–R, while internal alkynes can furnish substituted vinylstannanes. Variants using photochemical initiation or radical initiators such as AIBN are common. Other routes include tin–lithium exchange starting from vinyl halides or related vinyl tin precursors, though hydrostannation remains the principal method.

In organic synthesis, vinylstannanes are valuable reagents for Stille cross-coupling, where they act as nucleophilic vinyl partners with aryl or vinyl halides under palladium catalysis. The vinyl group is transferred to form new C–C bonds, enabling construction of extended conjugated systems and complex natural product targets. They are also used in multistep sequences where selective vinyl transfer is desirable.

Safety and handling: organotin compounds, including vinylstannanes, can be toxic and environmentally persistent. They are typically handled under inert atmosphere in fume hoods, with careful waste disposal following institutional and regulatory guidelines.