Sodium diphenylphosphide

Chloroprop-l-yne reacts with sodium diphenylphosphide in liquid ammonia to give diphenyl prop-1-ynyl phosphine (19). However, when the addition is carried out in THF a mixture of the prop-2-ynylphosphine... 

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... 

The reaction of (-)-menthyl chloride with sodium diphenylphosphide in tetra-hydrofuran requires 48-54 hr at reflux temperature for completion. The elimination side reaction is still observed. However, by-products (isomeric menthenes and diphenylphosphine) arising from the elimination reaction are easily removed by distillation. The overall conversion of (-)-menthyl chloride to (+)-NMDPP is about 34%, not counting the (+)-NMDPP oxide produced during a typical work-up. The (+)-NMDPP ligand is rather sensitive to air oxidation in solution and (+)-NMDPP oxide can be a very tenacious impurity, but careful crystallization of the phosphine from deoxygenated ethanol gives (+)-NMDPP in 95% (or higher) purity. 

The reaction of sodium diphenylphosphide with (+)-neomenthyl chloride (Fig. 14) gives (-)-menthyldiphenylphosphine (MDPP). The overall conversion of (+)-neomenthyl chloride to (-)-MDPP in a typical experiment is 25-30%.s The yield of (-)-MDPP was lower than the yield of (+)-NMDPP because elimination is a more serious competitive process for (+)-neomenthyl chloride than for (-)-menthyl chloride, the MDPP ligand is easily purified by crystallization from ethanol, and a purity of 98% (2% oxide) is attainable with one crystallization. 

In conjunction with the syntheses of (+)-NMDPP the relative effectiveness of lithium, sodium, and potassium diphenylphosphides was determined. Under a standard set of conditions the reaction of (-)-menthyl chloride with sodium diphenylphosphide gave the highest yield of (+)-NMDPP. The ratios of the yields of (+)-NMDPP were 1.0 1.55 1.16 for lithium, sodium, and potassium diphenylphosphide, respectively (17,32). 

A previous description of the synthesis of (CH3)3SiP(C6H5)2 in Inorganic Syntheses1 involves the initial preparation of sodium diphenylphosphide from diphenylphosphinous chloride. This method of preparation of the diphenylphosphide anion requires rigorous conditions and long reaction times. At least two other easier methods of preparation of the diphenylphosphide anion (lithium counterion) are known. One synthesis uses diphenyl-phosphine and n-butyllithium2 as reactants, whereas the second uses triphenylphosphine and elemental lithium.3,4 The second method is described here. 

Using equipment similar to that employed in the preparation of sodium diphenylphosphide, chlorotrimethylsilane (49.5 g., 0.45 mole, 59 ml.) dissolved in 100 ml. of dry w-butyl ether is added drop by drop to the refluxing, stirred suspension of sodium diphenylphosphide over a 2-hour period. After refluxing for an additional hour, the mixture is filtered and washed under nitrogen by means of a filtering stick similar to one previously described.11 The solvent is removed by distillation at atmospheric pressure, and the residual oil is fractionally distilled at 1 mm. pressure in a nitrogen atmosphere. In a typical experiment a 24.0-g. (62%) fraction is collected as product (b.p. 126-127°/1 mm., 1.600). 

Sodio-organophosphine reagents have also found considerable use in the past years. Aminyl radicals, R2N, are involved in the photo-assisted radical-nucleophilic substitution reactions between sodium diphenylphosphide and N-cyclopropyl-A-ethyl-/ -toluenesulfonamide in liquid ammonia, which after oxygenation, leads to the aminoalkyldiphosphine dioxide (80) as the principal product. The reactions of sodio-organophosphide reagents with chloroalkyl... 

The chiral phosphines (7) and (8) have been obtained by the reaction of sodium diphenylphosphide with menthyl chloride and neomenthyl chloride, respectively. ... 

Dihalogenoethyl cyanides undergo dehalogenation to acrylonitrile on reaction with either secondary or tertiary phosphites, presumably through initial attack of phosphorus on halogen. Surprisingly, bis(diphenylphosphinyl)-amine (65) is the product of the reaction of sodium diphenylphosphide and... 

Many applications of sodium and potassium organophosphides have been reported in the past year. The reaction of sodium diphenylphosphide with tosylates has been employed in the synthesis of steroidal phosphines. This reagent has also been used in the synthesis of a range of carbohydrate-derived phosphines, and in the synthesis of the phosphine (26), which can be linked to a silica support by treatment with acid. The reaction of sodium diphenylphosphide with o-difluorobenzene affords a convenient, one-pot synthesis of o-bis(diphenyl-phosphino)benzene. Sodium dimethylphosphide has been used to convert... 

The more effective methods of preparation of polymer-bound triarylphosphine for Wittig reactions are 1) lithiation of the polymer followed by reaction with chlorodi-phenylphosphine, and 2) reaction of brominated polystyrene with lithium or sodium diphenylphosphide as shown in Scheme 3. 

Sodium diphenylphosphide reacts with 3-bromopropyne in liquid ammonia to furnish propyne and aminodiphenylphosphine (37), even though 3-... 

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