Phosphine sulfide, with

The use of other phosphorus-sulfur reagents for heterocyclic synthesis appears rare. It would be interesting to investigate in more detail the reaction of compounds, such as the phosphine sulfides, with organic substrates. Triphenylphosphine sulfide is an effective sulfur transfer agent, as it converts oxiranes into thiiranes in good yield. The reaction proceeds with retention of configuration.128... 

Other related compounds are the diphosphine disulfides R2P(S)P(S)R2 14, which contain a direct phosphorus-phosphorus bond, and polysulfur fe(dior-ganophosphine sulfides) R2P(S)-S -P(S)R2 in which the two phosphorus centres are connected by a chain of one of more sulfur atoms. R2P(S)P(S)R2 compounds are accessible from heating secondary phosphine sulfides with thiophosphinic chlorides (Equation 10) or by reaction of fephosphines with... 

Menoyo, B., Elizalde, M.R, Almela, A. 2002. Determination of the degradation compounds formed by the oxidation of thiophosphinic acids and phosphine sulfides with nitric acid. Anal. Sci. 18 799-804. 

Phosphine sulfides, with trinuclear Ru clusters, 6, 748 Phosphinidene-bridged ditantalum(IV) complexes, preparation, 5, 183 Phosphinidenes... 

Thiophosphinic halides behave differently purely aliphatic members of this series give only tertiary phosphine sulfides with either alkyl or aryl Grignard... 

This procedure also incorporates the use of bis(3-dimethylamino-propyl)phenylphosphine as a combined amine-phosphine reagent. The merits of using this basic phosphine as opposed to a tertiary amine and a phosphine lies in the ease of workup. Excess phosphine and phosphine sulfide can be removed by extraction with aqueous dilute acid. 

Examples of the intermolecular C-P bond formation by means of radical phosphonation and phosphination have been achieved by reaction of aryl halides with trialkyl phosphites and chlorodiphenylphosphine, respectively, in the presence of (TMSlsSiH under standard radical conditions. The phosphonation reaction (Reaction 71) worked well either under UV irradiation at room temperature or in refluxing toluene. The radical phosphina-tion (Reaction 72) required pyridine in boiling benzene for 20 h. Phosphinated products were handled as phosphine sulfides. Scheme 15 shows the reaction mechanism for the phosphination procedure that involves in situ formation of tetraphenylbiphosphine. This approach has also been extended to the phosphination of alkyl halides and sequential radical cyclization/phosphination reaction. ... 

Reaction of cyclic tetrasulfido complexes of heavier group 14 elements bearing bulky substituents such as Tbt(Ar)MS4 (M=Si, Ar=Tip M=Ge, Ar=Tip M=Sn, Ar=Ditp) with 3 equivalents of phosphines afforded the successful isolation of the first stable double-bonded compounds between heavier group 14 elements and sulfur atom (heavy ketones), Tbt(Ar)M=S, accompanied by the quantitative formation of the corresponding phosphine sulfides (Scheme 40) [13, 15, 112, 113]. On the other hand, their lead an-... 

Phosphine sulfides or selenides are well-known ligands in gold(I) chemistry. With monophosphine complexes of the type [AuX(SPR3)] (X = C1, Br, CN PR3 = PPh3, PCy3, PPh2Py,... 

Other complexes with phosphine sulfides are the three coordinate [Au (S-PPh2)2C(PPh2S) (PPh2Bun)],302 the /i4-phospha-l-thiethane compound [Fe3(CO)9(/i4-PS)(AuPPh3)2] (558),3 27 and the gold(I) dendrimers containing P=NP=NP=S or P=NP=S groups as (559).3028... 

Gold(I) complexes with P,S (or Se) donor ligands are in many cases derived of phosphine sulfides or selenides as [Au2(PPh2CH2PPh2Se)2](C104)2,3140 and [Au(PPh2CH2PPh2Se)2]+ (595),1403,3141 [Au2(PPh3)2(p-SPPh2Py)](BF4)2,1427 or phosphine thioethers such as... 

Tertiary phosphine sulfides are generally stable compounds and are not easily oxidised by air, although they can be oxidised by hydrogen peroxide or dilute nitric acid. The analogous tertiary phosphine selenides and tellurides are however, more reactive to oxidation. Similar to the sulfides they can be prepared from the direct reaction of elemental chalcogen with a tertiary phosphine (Equation 1). Tertiary phosphine selenides are also accessible from tertiary phosphines using KSeCN as the selenium source instead of the element itself. 

Larger chalcogen-phosphorus heterocycles, although less common in the literature, are accessible via a variety of synthetic routes.2,83,84 For example, the cyclic trimer (SPR)3 (R = 2,4,6-tri-tert-butylphenyl) contains a puckered six-membered P3S3 ring and is produced in the reaction of a phosphinic chloride with lithium sulfide (Equation 73).98 Additionally (R P)3Se5 (R = 2,4-di-tert-butyl-6-wopropoxyphenyl), synthesised from the oxidation of a primary phosphine with three equivalents of elemental selenium (Equation 74), has... 

The Reactions of Phosphine Sulfides and Selenides with Iodine... 

A mixture of diphenyl-3-(2-morpholino-l-cyclohexenyl)phosphine sulfide (3.25 g, 8.5 mmol) and triethylamine (0.91 g, 9 mmol) in benzene (20 ml) was added to a solution of phosphorus tribromide (2.30 g, 8.5 mmol) in benzene (20 ml). After 2 h, a mixture of methanol (0.55 g, 17 mmol) and triethylamine (1.82 g, 18 mmol) in benzene (20 ml) was added with stirring to the solidified mass. After 1 h, the mixture was filtered, the filtrate was evaporated, and the residue was ground with petroleum ether. There was thus isolated pure dimethyl 3-dip henylthiophosphoryl-2-morpholino-l-cyclohexenylphospho-nous acid of melting point (mp) 193-196°C (3.14 g, 78%). 

Commercially available tetraphenyldiphosphine adds to terminal alkynes in the presence of a radical initiator (V-40) and Ph2PCl in refluxing benzene (Equation (63)).164 After treatment of the reaction mixture with sulfur, phosphine sulfides are obtained as a mixture of stereoisomers. 

The key issues reduce to these (a) given that a phosphine sulfide is the product, at what positions do phosphine atoms attack in the transition state (b) What is the role for pyridine (c) Although 21 is formed from 20, with excess phosphine 23 results given that 21 -23 is slower than 20 23 and 23 -21, is 21 an intermediate along the pathway of the 20— 23 reaction ... 

For monosulfonation of PPh3 the reaction mixture can be heated for a limited time [1-3] while multiple sulfonation is achieved hy letting the solution stand at room temperature for a few days [4-10], In this simplest way of the preparation several problems may arise. Under the harsh conditions of sulfonation there is always some oxidation of the phosphine into phosphine oxide and phosphine sulfides are formed, too. Furthermore, selective preparation of TPPMS (1) or TPPDS (2) requires optimum reaction temperature and time and is best achieved by constantly monitoring the reaction by NMR [10] or HPLC [7]. Even then, the product can be contaminated with unreacted starting material. However, 1 can be freed of both the non-sulfonated and the multiply sulfonated contaminants by simple methods, and in the preparation of TPPTS (3) contamination with PPh3, 1 or 2 is usually not the case. Direct sulfonation with fuming sulfuric add was also used for the preparation of the chelating diphosphines 34-38, 51, 52. 

Tris(trimethylsilyl)silane reacts with phosphine sulfides and phosphine selen-ides under free radical conditions to give the corresponding phosphines or, after treatment with BH3-THF, the corresponding phosphine-borane complex in good to excellent yields (Reaction 4.45) [82]. Stereochemical studies on P-chiral phosphine sulphides showed that these reductions proceed with retention of configuration. An example is given in Reaction (4.46). 

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