Catalytic
asymmetric hydrofunctionalization of π-bonds has
been extensively studied, but the asymmetric hydrofunctionalization
of alkynes that affords atropoisometric products remains heavily underexplored.
We herein report [Rh(COD)OAc]2/Mg(NTf2)2-catayzed highly atroposelective hydroselenation of two classes
of 1-alkynylindoles using selenophenols, where the Mg(II) salt both
activates the Rh catalyst and provides a key NTf2 anion
essential for the catalytic activity and enantioselectivity, affording
C–N axially chiral trisubstituted olefins that bear a relatively
low racemization barrier (ΔG
‡ ∼ 27 kcal/mol). The catalytic system features high activity,
mild reaction conditions, good functional group tolerance, and high
regio-, (E)-, and enantioselectivity. The selenoether
moiety in the product framework can be readily functionalized to give
synthetically useful products.