Xantphos

Xantphos is an organophosphorus compound derived from the heterocycle xanthene. It is used as a bidentate ligand and is noteworthy for having a particularly wide bite angle. Such ligands are useful in the hydroformylation of alkenes. Illustrative of its wide bite angle, it forms both cis and trans adducts of platinum(II) chloride.

The ligand is prepared by di-lithiation of 9,9-dimethylxanthene with sec-butyllithium followed by treatment with chlorodiphenylphosphine.