(S)-iPr-PHOX, or (S)-2-[2-(diphenylphosphino)phenyl]-4-isopropyl-4,5-dihydrooxazole, is a chiral, bidentate, ligand derived from the amino alcohol valinol.

It is part of a broader class of phosphinooxazolines ligands and has found application in asymmetric catalysis.

(S)-iPr-PHOX is prepared using the amino alcohol valinol, which is derived from valine.

This yields an air stable zinc complex which must be treated with bipyridine in order to obtain the free ligand.

Iridium complexes incorporating (S)-iPr-PHOX have been used for asymmetric hydrogenation.