From Halogenophosphine and Organometallic Reagent

Preparation.—From Halogenophosphine and Organometallic Reagents. The cyclo-pentadienylphosphines (1) have been obtained from the reaction of cyclopenta-dienylthallium with chlorophosphines in ether.1 Diphenyl(4-pyridyl)phosphine (2) is prepared from 4-pyridyl-lithium and chlorodiphenylphosphine,2 and an improved procedure for the synthesis of tri-(2-pyridyl)phosphine (3) from 2-pyridyl-lithium and phosphorus trichloride has been reported.3 

Treatment of phosphorus trichloride with an excess of the Grignard reagent (4) leads to the sterically hindered phosphine (5).4 A sample of 14C-labelled triethyl-phosphine has been synthesized from 14C-labelled ethylmagnesium iodide and phosphorus trichloride.5 The reaction of chlorodiphenylphosphine with the Grignard 

From MetallatedPhosphines. The synthesis of polymeric tertiary phosphines based on the reaction of lithium diphenylphosphide with chloromethylated polystyrenes continues to attract interest.9 10 Considerable breakdown of the carbon-carbon back-bone of PVC occurs on reaction with lithium diphenylphosphide in THF, and only oligomers of low molecular weight result.11 The potassium salt (9) reacts with chloromethylated polystyrene to form the polymeric diphosphine (10).12 

The w-chloroalkyldiphenylphosphines (11) have been prepared by the reaction of equimolar quantities of sodium diphenylphosphide with aco-dichloroalkanes. Whereas the phosphine (11 n = 3) can be converted into the Grignard reagent (12), which reacts with dimethylchlorophosphine to form the unsymmetrical diphosphine (13), the Grignard reagent (14) undergoes a -elimination reaction to regenerate diphenylphosphide ion.13 

Similarly, the chloroalkylarsine (15) (obtained from lithium diphenylarsenide and 1,2-dichloroethane) reacts with lithium diphenylphosphide to form the mixed phosphine-arsine (16).14 

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A. From Halogenophosphine and Organometallic Reagent.—Mesityl-magnesium bromide reacts with chlorodiethylphosphine and dichloroethyl-phosphine at — 10 °C in THF to yield mesityldiethylphosphine and dimesitylethylphosphine respectively. ... 

From Halogenophosphines and Organometallic Reagents.- A greatly improved route to tris-t-butylphosphine is afforded by the addition of a benzene solution of phosphorus trichloride to a pentane solution of t-butyllithium. Direct metallation of benzenechromiumtricarbonyl with butyllithium at -30°C, followed by... 

Preparation.—From Halogenophosphines and Organometallic Reagents. A series of trimethylsilylcyclopentadienylphosphines, e.g. (1), has been prepared from the appropriate trimethylsilylcyclopentadienyl-lithium and halogenophosphine. Similarly, the reaction of pentamethylcyclopentadienyl-lithium with chlorodimethyl-phosphine gives the phosphine (2), which is reported to be thermally stable. ... 

Preparation.—From Halogenophosphine and Organometallic Reagents. An improved synthesis of trimethylphosphine from phosphorus trichloride and methyl-lithium at —78 °C has been described. Another improved high yield synthesis of the same phosphine uses the reaction of triphenyl phosphate with methylmagnesium iodide. Other trialkylphosphines have also been prepared by this latter method. 

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