Xantphos

Chembox new
ImageFile = Xantphos.png ImageSize =
ImageFile1 = Xantphos-3D-balls.png ImageSize1 =
IUPACName = 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene
OtherNames = Xantphos
Section1 = Chembox Identifiers
CASNo = 161265-03-8
PubChem = 24889800
SMILES =
Section2 = Chembox Properties
Formula = C₃₉H₃₂OP₂
MolarMass = 578.62 g/mol
Appearance = colourless solid
Density = 1.34 g/mL
MeltingPt = 224-228 °C
BoilingPt =
Solubility = organic solvents
Section3 = Chembox Hazards
MainHazards = flammable
FlashPt =
Autoignition =

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. [cite journal | author = Piet W. N. M. van Leeuwen, Paul C. J. Kamer, Joost N. H. Reek, and Peter Dierkes | title = Ligand Bite Angle Effects in Metal-catalyzed C-C Bond Formation | year = 2000 | journal = Chemical Reviews | volume = 100 | issue = | pages = 2741–2769 | doi = 10.1021/cr9902704] Illustrative of its wide bite angle, it forms both cis and trans adducts of platinum(II) chloride. A related bidentate ligand with a greater bite angle is spanphos.

The ligand is prepared by double directed lithiation of 9,9-dimethylxanthene with sec-butyllithium followed by treatment with chlorodiphenylphosphine. [cite journal | author = Mirko Kranenburg, Yuri E. M. van der Burgt, Paul C. J. Kamer, Piet W. N. M. van Leeuwen, Kees Goubitz, and Jan Fraanje | title = New Diphosphine Ligands Based on Heterocyclic Aromatics Inducing Very High Regioselectivity in Rhodium-Catalyzed Hydroformylation: Effect of the Bite Angle | year = 1995 | journal = Organometallics | volume = 14 | issue = | pages = 3081–3089 | doi = 10.1021/om00006a057]

References