Bipyridine Ligand-Promoted cis-Selective Hydroboration of Alkynes with Chromium Catalysis

The chromium-catalyzed hydroboration of alkynes under mild conditions was reported. Low-cost chromium(III) chloride combined with 4,4'-di-tert-butyl 2,2'-bipyridine as the ligand and magnesium as the reductant shows high reactivity, which can catalyze and promote the hydroboration of alkynes with pinacolborane, thereby providing a strategy to form borylated olefins at ambient temperature.