SUMMARY:  Palladium-catalyzed underexplored atroposelective hydrophosphination of sterically hindered internal alkynes with secondary phosphines has been realized, affording C-N axially chiral trisubstituted olefins (vinylphosphines) in excellent regioselectivity, (E)-selectivity, and enantioselectivity. The axial chirality was constructed via integration of hydrophosphination and dynamic kinetic transformation of the alkynes, with both symmetrical and nonsymmetrical secondary phosphines being applicable.