(2-Bromophenyl)diphenylphosphine is an organophosphorus compound with the formula (CHBr)P(CH). It is a white crystalline solid that is soluble in nonpolar organic solvents. The compound is used as a precursor to the 2-lithiated derivative of triphenylphosphine, which in turn is a precursor to other phosphine ligands.
Preparation The compound has been prepared by several methods. An efficient route is the coupling reaction of diphenylphosphine and 2-bromoiodobenzene, which is catalyzed by palladium complexes (Ph = CH): CHBr(I) + HPPh + EtN → PhP(CHBr) + [EtNH]I
The compound is isomorphous with (2-tolyl)diphenylphosphine.
Lithiation with butyl lithium gives o-lithiated triphenylphosphine. The bromide also forms a Grignard reagent. These metallated phosphines are versatile reagents.Hartley, J. G., Venanzi, L. M., Goodall, D. C., "The preparation and complex-forming properties of one tritertiary and one tetratertiary phosphine", J. Chem. Soc. 1963, 3930. BrC6H4PPh2 + Mg → BrMgC6H4PPh2 2 BrMgC6H4PPh2 + PhPCl2 → PhP[C6H4PPh2]2 + 2 MgClBr
References