Phosphinooxazolines

Phosphinooxazolines (often abbreviated PHOX) are a class of

• When X = fluorine coupling involves anionic displacement with a alkali metal diphenylphosphide.^[3]
• 2-Bromoaryl oxazolines can be converted into a
  copper iodide-catalysed reaction.^[5]
• Aryl oxazolines undergo directed ortho lithiation, and the resulting 2-lithio derivative then can be treated with chlorodiphenylphosphine.^[6]

Of these methods, the

Phosphinooxazoline complexes have been widely tested in homogeneous catalysis.^[8][9][10]

Allylic substitutions

PHOX-based palladium complexes catalyse enantioselective allylic substitutions.

Substitutions include allylic alkylations (Tsuji-Trost reaction),^[11] aminations,^[12] and sulfonylations.^[13]

Heck Reaction

Palladium complexes containing chiral phosphinooxazolines are efficient catalysts for the Heck reaction.^{[14] [15]} Pd-PHOX catalysts have also been used for intramolecular Heck reactions and examples exist where they have been shown to be superior to more common ligands such as BINAP.^[16]

Asymmetric Hydrogenation

In asymmetric hydrogenation iridium complexes of phosphinooxazolines catalyse 'classic' hydrogenation.^[17] Related ruthenium and palladium catalysts effect transfer hydrogenation.^[1] In addition to theoretical studies,^[18] the structural^[19] and kinetic properties^[20]

See also

Other oxazoline based ligands

• (S)-iPr-PHOX - A specific PHOX ligand
• Bisoxazolines (BOX)
• Trisoxazolines (TRISOX)

Structurally related ligands

• Trost ligand
• Diphenyl-2-pyridylphosphine

References