Stereoselective Synthesis of Cis- and Trans-Tetrasubstituted Vinyl Silanes Using a Silyl-Heck Strategy and Hiyama Conditions for Their Cross-Coupling.

We report a palladium-catalyzed, three-component carbosilylation reaction of internal symmetrical alkynes, silicon electrophiles, and primary alkyl zinc iodides. Depending on the choice of ligand, stereoselective synthesis of either cis- or trans-tetrasubstituted vinyl silanes is possible. We also demonstrate conditions for the Hiyama cross-coupling of these products to prepare geometrically defined tetrasubstituted alkenes.