Organocatalytic Atroposelective Hydroselenation of Alkynes To Access Axially Chiral Vinyl Selenides

While the catalytic asymmetric hydrofunctionalization of unsaturated hydrocarbons has been widely investigated, the asymmetric hydrofunctionalization of alkynes, which yields atropoisomeric products, remains significantly underexplored. Herein, we showcase an unprecedented organocatalytic atroposelective hydroselenation of alkynes with selenols, leading to the formation of axially chiral vinyl selenides. This organocatalytic, atom-economic process occurs under mild conditions and exhibits high enantio-, regio-, and E-stereoselectivity, despite the relatively low racemization barrier (Delta G double dagger = similar to 27 kcal/mol) of the formed axially chiral vinyl selenides. Insights from detailed Density Functional Theory (DFT) studies elucidate the origins of these high selectivities.