From Halogenophosphines and Organometallic Reagents

1 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 

Conventional aryl Grignard procedures have been used in the 

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. 

Triarylphosphines with formyl or acetyl groups substituted into the aromatic rings can be prepared by a Grignard reaction using ethylene keta derivatives. The resulting phosphines (1) are treated with toluene-p-sulphonic acid. The acetyl derivatives may also be prepared by oxidation of the ethyl derivatives (2) followed by reduction with trichlorosilane.  

A series of phosphines (3) containing alkenyl groups has been prepared by reaction of the chlorophosphine with the appropriate Grignard reagent. Tertiary arylethynylphosphines, e.g. (4), can be easily prepared by heating 

Organosilylphosphines, e.g. (5), are obtained directly from the reaction of chlorophosphines and trimethylchlorosilanes in the presence of magnesium.  

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.  

Direct metallation of cross-linked polystyrenes, using the n-butyl-lithium-TMED A reagent, followed by treatment with chlorodiphenylphosphine, affords an improved 

Two unusual fluorinated phosphines, (6) and (7), have been prepared by the reactions of organolithium reagents with appropriate halogenophosphines.  

The sterically bulky phosphines (8) have been prepared by the Grignard method from chlorodi(t-butyl)phosphine and chlorodicyclohexylphosphine. In certain iridium(i) complexes, metallation of these phosphines occurs on the terminal olefinic carbon atom. Treatment of a, )-dialkynyl-lithium reagents with chlorodi-(t-butyl)-phosphine gives the diacetylenic diphosphines (9), which form large ring compounds when they form complexes with transition metals.  

Interest in the synthesis of compounds containing the P(CHaC02R) grouping continues, and routes involving the reactions of chlorophosphines with sodium enolates of acetate esters and Reformatsky reagents have been reported. A range 

The reactions of various halogenophosphines, PCl Ph3 (n = 1—3), with organolithium reagents have given rise to the alkynylphosphines (7), the o-fluorophenylphosphines (8), and the heteroarylmethylphosphine (9).  

The generation of organolithium reagents by o-lithiation of alkyl phenyl ethers, dialkylaminobenzenes, and benzyldialkylamines followed by their reaction with halogenophosphines has afforded a range of new substituted arylphosphines, e.g., (10) and the chiral phosphine (11). Directed-lithiation of 1-dimethyl-aminonaphthalene, followed by treatment with chlorodiphenylphosphine, affords a more direct route to the phosphine (4). The diphosphines (12) are formed in the reactions of chlorodiethylphosphine with u-lithio lithium phenolate 

2 Preparation of Phosphines from Metallated Phosphines.- The generation of arylphosphide reagents by the reductive cleavage of carbon-phosphorus bonds using alkali metals has received detailed study for a wide range of functionalised triarylphosphines and related 

Silylphosphide reagents have generated considerable interest over the past year. Alkali metal bis(trimethylsilyl)phosphides are useful building blocks for the synthesis of isotetraphosphines PfPRjlj (R = Ph or cyclohexyl) via their reactions with 

The reactions of lithiophosphide reagents with alkyl halides or sulphonate esters have continued to find wide application in the synthesis of new phosphines. A series of phosphino-ethers, e.g., (22), has been prepared from the reactions of chloromethyl-substituted ethers with lithium diphenylphosphide. A one-step synthesis of macrocyclic phosphino-ethers and -thioethers (23) is afforded by the reactions of dilithio-organophosphides with bis(j8-chloroethyl)-ethers and -thioethers derived from ethane-1,2-diol and ethane-1,2-dithiol, respectively. A new family of water soluble phosphonio-phosphine ligands (24) has been prepared by the reaction of a,o)-dihaloalkanes with one mole of lithium diphenylphosphide, followed by quatemisation of the intermediate w-haloalkylphosphine with trimethylphosphine. The new ligand system (25) has been prepared by the reaction of chloromethylbenzene-chromium tricarbonyl with 

Organophosphorus Chemistry, Volume 32 The Royal Society of Chemistry, 2002 

Both organolithium and Grignard reagents have been employed in a stepwise synthesis of the chiral phosphine (46) from ( —)menthyl chloride. The 

Metallation of the bis(bromovinyl)benzene 7 with t-butyllithium, followed by treatment with phenyldichlorophosphine, provides a route to the benzo- 

Ortho-lithiation of an O-protected m-fluorophenol, followed by treatment with phosphorus tribromide and aqueous acid deprotection, has given the phosphino-phenol 18. In the presence of potassium t-butoxide in an aprotic solvent, this is converted into the non-planar system 19, which exhibits pyroelectric properties. An organolithium route to the alkynylphosphine 20 has been developed. The same paper also reports a new route to the lithiated alkynylphosphine 21 and a study of its reactivity towards electrophiles. Diastereoselective lithiation of 

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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. ... 

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... 

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