C−H Bond Activation and Subsequent C−C Bond Formation Promoted by Osmium:  2-Vinylpyridine−Acetylene Couplings

Complex OsH₂Cl₂(PⁱPr₃)₂ promotes the C−H activation of 2-vinylpyridine and subsequently couples the activated substrate with a second 2-vinylpyridine and two acetylene molecules. In the absence of 2-vinylpyridine, the activated substrate is coupled with an acetylene unit to afford a 2-butadienylpyridine derivative.