Intermolecular Coupling Involving Hydrometallation or C-H Bond Activation

Intermolecular Coupling Involving Hydrometallation or C-H Bond Activation 

3-Dienes have been synthesized by cross-coupling of alkenes and alkynes involving other types of mechanisms, such as initial hydrometallation or C-H bond activation. 

Conjugated dienes were thus selectively obtained by hydrovinylation of alkynes catalyzed by a cationic ruthenium alkylidene complex [43] (Eq. 31). This reaction is thought to be promoted by the ruthenium hydride species resulting from the deprotonation of the 5-methyl group of the metallic precursor, followed by the sequential insertion of alkyne and ethylene into the metal-hydride and metal-vinyl bonds. 

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