Chiral phosphorus compounds are widely employed as organocatalysts or ligands for enantioselective transition-metal catalyzed transformations.^[1] Most commonly, the chirality comes from a stereogenic carbon, an axis of chirality, or a chiral plane. One might expect a better relay of chirality during catalysis with P-stereogenic phosphorus ligands due to a closer proximity to the transition metal. However, this area of research remains under explored due to challenges associated with P-stereogenic ligand synthesis.

Herein we report the first example of a chiral cyclopentadienyl^[2] Rh(III)-catalyzed asymmetric synthesis of P-stereogenic phosphinamides. For prochiral phosphinamide substrates, enantioriched heterocycles were accessed via annulation with internal alkynes.^[3] In contrast, with chiral phosphinamide substrates, kinetic resolution yielded both the cyclic phosphamides and unreacted starting materials, with selectivity-factors up to 50. Kinetic studies reveal that a concerted-metalation-deprotonation is the stereo-determining step when an inorganic base is employed, in contrast to previous reports from our group.^[4]

[1] Phosphorus Ligands in Asymmetric Catalysis: Synthesis and Applications, Vols. 1-3 (Eds. : A. Börner), Wiley-VCH, Weinheim, 2008.
[2] C. G. Newton, D. Kossler, and N. Cramer, J. Am. Chem. Soc. 2016, 138, 3935.
[3] Y. Sun, N. Cramer, Angew. Chem. Int. Ed. 2017, 56, 364.
[4] B. Ye, N. Cramer, Acc. Chem. Res. 2015, 48, 1308.