Hydrobismuthation: Insertion of Unsaturated Hydrocarbons into the Heaviest Main Group Element Bond to Hydrogen.

The bismuth hydride (2,6-MesHC)BiH (, Mes = 2,4,6-trimethylphenyl), which has a Bi-H H NMR spectroscopic signal at δ = 19.64 ppm, was reacted with phenylacetylene at 60 °C in toluene to yield [(2,6-MesCH)BiC(Ph)=CH] () after 15 min. Compound was characterized by H, C NMR, and UV-vis spectroscopy, single crystal X-ray crystallography, and calculations employing density functional theory. Compound is the first example of a hydrobismuthation addition product and displays Markovnikov regioselectivity. Computational methods indicated that it forms via a radical mechanism with an associated Gibbs energy of activation of 91 kJ mol and a reaction energy of -90 kJ mol.