The Reduction of Aryl Diethyl Phosphate Esters with Lithium Di-tert-butylbiphenylide Radical Anion: Aromatic Hydrocarbons via the Deoxygenation of Phenols

Abstract

The reduction of aryl diethyl phosphate esters by lithium 4,4′-di-tert-butylbiphenylide (LiDTBB) in THF at 0 °C is described. The reactions can be carried out either stoichiometrically (3.0 equiv LiDTBB) or with only a catalytic amount of DTBB (0.25 equiv) in the presence of lithium (2.1-3.0 equiv) and the phosphate. Products are separated from DTBB by solubility differences, by acid/base vs. neutral extraction, or by flash chromatography.

Key words

reduction - phosphates - deoxygenation - phenols - arenes

References

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14

Ar should be used rather than N₂ as the inert atmosphere because lithium reacts slowly with nitrogen to form lithium nitride, which coats the lithium surface and can slow the reaction with DTBB.