Triphenylphosphonium iodide

The present preparation illustrates a general and convenient method for the fnms-iodopropenylation of an alkyl halide.4 The iodopropenyl-ated material is not usually stable but is a useful synthetic intermediate. For example, it forms a stable crystalline triphenylphosphonium salt for use in the Wittig reaction, and under Kornblum reaction conditions (DMS0-NaHC03, 130°, 3 minutes) it gives an (E)-a,/9-unsaturated aldehyde.4 In addition to the phosphonium salt described in Note 15, the following have been prepared (4-p-methoxyphenyl-2-butenyl)-triphenylphosphonium iodide [Phosphonium, [4-(4-methoxyphenyl)-2-butenyl]triphenyl-, iodide], m.p. 123-127° (2-octenyl)triphenyl-phosphonium iodide [Phosphonium, 2-octenyltriphenyl-, iodide], m.p. 98° and (2-octadecenyl)triphenylphosphonium iodide [Phosphonium, 2-octadecenyltriphenyl-, iodide], m.p. 50°. 

H6]-Leukotriene A4 methyl ester, 17, has been synthesized14 by Wittig olefination of epoxy dienal 18 with the key reagent 3,4,6,6,7,7-[2H6]-(Z)-(3-nonen-1-yl)triphenylphosphonium iodide, 19 (equation 9). 17 is employed as stable isotope internal standard for the MS trace analysis of eicosanoids15-17. 

A thorough investigation has shown that the Tanigawa amination of alcohols, in which the corresponding alkoxide (282) is treated in DMF with A-methyl-A-phenylamino-triphenylphosphonium iodide (283) and a secondary amine at 80 °C, does not proceed at this temperature. In situ generation of the A.A-dimethylamino analogue (284) by reaction of (283) with dimethylamine, however, does lead to a smooth reaction at 90 °C. The proposed mechanism involves a pentacoordinated intermediate (285). " ... 

In the presence of dibutyl telluride, iodomethyl triphenylphosphonium iodide reacts with aldehydes, in accordance with a Wittig-type olefmation, giving methylenation products. ... 

Methylenation reaction (typical procedure) A mixture of iodomethyl triphenylphosphonium iodide (0.530 g, 1.0 mmol), dibutyl telluride (0.242 g, 1.0 mmol) and p-bromoben-zaldehyde (0.096 g, 0.5 mmol) in THF (5 mL) is heated under reflux for 30 h, then cooled and filtered. The residue is purified by TLC, giving p-bromostyrene (0.080 g (87%)). 

Photography, Photography (qv) represents one of the oldest industrial uses of iodide. The sensitive silver salt in rapid negative emulsions contains up to 7% or more silver iodide [7783-96-2], Agl. From 1969 to 1985 estimates on iodine consumption for this purpose varied from 150 to 270 t/yr (66). Triphenylphosphonium iodide is also among the iodine derivatives used in photography. This derivative permits faster development and higher contrast photography. 

We were able to direct the rearrangement 23—24 so that no disproportion into 9. and 30. occurred (13). The adducts 24 are stable and can now be used for hydroboration reactions whereby a suitable method for the elimination of triphenylphosphane from complex 24 must be used. This can be achieved with benzyl-iodide jjj. On a cIcTi-tion of the iodo compound 25 and an olefin 2 to a solution of 2 in tetrahydrofuran, the benzyl-triphenylphosphonium iodide precipitates and the free R-BH2 adds to the olefin 2 forming the tri-... 

This lipophilic cationic compound 267 has been synthesized410, as shown in equation 195, from / -iodoaniline via the triazene 268, reaction of the latter with triphenylphosphine and labelling the triphenylphosphonium iodide 269 with 125I. 267 is a potential agent for PDT (photodynamic therapy) for central nervous system malignancy411l-41 3. 

Dibutyl telluride 59 reacts with iodomethyl triphenylphosphonium iodide to give triphenylmethylidene phosphor-ane, which reacts with aldehydes leading to the methylenation products in good yields.119 The same reagent 59 also assists the reaction of dibromomalonates 60 with aldehydes and activated olefins affording alkylidene malonates 61 and cyclopropanes 62 derivatives, respectively (Scheme 30). 

Fleet, G W J, Shing, T K M, Enantiospecific synthesis of (35 -hydroxy-25 -methyl) butyl triphenylphosphonium iodide a precursor for the chiral side chain of pseudomonic acid. Tetrahedron Lett., 24, 3657-3660, 1983. 

Silylation of phosphorane 1 to [l-(trimethylsilyl)cyclopropyl]triphenylphosphonium iodide (14) can be achieved with chlorotrimethylsilane. ... 

A similar approach had been reported earlier by Bestmann and coworkers" in their synthesis of hexadeuteriated leukotriene A4 methyl ester. C-alkylation of the tetrahy-dropyranyl ether of 3-butyn-l-ol with 2,2,3,3-tetradeuterio-l-iodopentane, prepared in 4 steps from propargyl alcohol, and subsequent protective group removal afforded the tetradeuteriated acetylenic alcohol 46 (equation 30). Semideuteriation of the alkynol and further transformation by known methods produced the labeled key reagent 3,4,6,6,7,7-hexadeuterio-(Z)-(3-nonen-l-yl)triphenylphosphonium iodide (47). Wittig olefination of epoxy dienal 45 with the labeled ylide generated from 47 completed the synthesis of... 

Antipyrinylmethyl)triphenylphosphonium iodide 3 52 (Dimethylaminomethyl)antipyrine methiodide (3.87 g, 0.01 mole) and triphenylphosphine (3.93 g, 0.015 mole) in dimethyl-formamide (25 ml) are boiled under reflux for 3 h while nitrogen is passed through the solution, the trimethylamine evolved (95%) being absorbed in O.lN-hydrochloric acid. The reaction mixture is then freed from solvent, and the residue is powdered and boiled with benzene which removes unchanged phosphine. There remains a crude product (5.6 g, 96 %) which after recrystallization from water has m.p. 193-194° (3.9 g, 67%). 

This reagent is prepared in situ by treatment of (2-ethoxyl-l- ropenyl)-triphenylphosphonium iodide with -butyllithium. 

Preparative Methods can be prepared from (phenylthiomethyl) triphenylphosphonium iodide and A,A(-dimethylmethylene ammonium chloride in refluxing acetonitrile (eq 1). ... 

Srivastava, P. C., Knapp, F. F. 1984. [(E)-l-[I-123]iodo-l-penten-5-yl]triphenylphosphonium iodide— Convenient preparation of a potentially useful myocardial perfusion agent. J. Med. Chem. 27 978-981. 

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