Phosphonium derivatives

Very few examples of bridging non-cyclic methanides of gold are known. Among them the complex 79 has been reported as the result of the reaction of phosphine-phosphonium derivatives with acetylacetonate derivatives of gold(I) [103,104]. The complexes 80 [89,98], already seen in previous paragraphs, cor-... 

On 100% acrylic materials the quaternary ammonium retarders are used almost exclusively. Other types have been evaluated, however. For example, saturated alkylamines (RNH2 R = C10, C12, C14 and C16 hydrophobes) were found to be just as effective as the quaternary types although other factors, such as aqueous solubility at the optimal dyebath pH and resistance to subsequent discoloration, favour the quaternary compounds [34]- On the other hand, bis (hydroxyethyl) coco amine (12.10) had relatively little effect and the amphoteric carboxymethyldimethylcocoamine (12.11) none at all, although dimethyl-cocoamine oxide (12.12) was quite an effective retarder [34]- Other cationic compounds used [43,44] have included alkylpyridinium salts, imidazoles and imidazolinium salts, alkyldiamines, alkylpolyamines, as well as sulphonium and phosphonium derivatives. 

However, in the presence of a suitable Lewis base the polymerization becomes living, due to the nucleophihc stabilization of the growing cation generated by the added base. (3) Initiator, strong Lewis acid and onium salt as additive The previous method cannot be easily applied in polar media. In this case the living cationic polymerization is promoted by the addition of salts with nucleophihc anions, such as ammonium and phosphonium derivatives. 

The mercuration of phosphonium derivatives has also been observed. The methylene group of the dimeric palladium complex 63 substituted by a carbonyl and a phosphonium functionality is readily mercurated upon reaction with Hg(OAc)2 to afford complex 64 (Equation (22)).7 Further studies demonstrated that the presence of a triphenylphosphonium group alone is sufficient to promote proton-mercury exchange. For example, the reaction of... 

Sulfides (111) can be obtained by the interaction of sulfur with betaines (103), (104) [Eq. (98)] (80IZV1438 84IZV2089). Such reaction is not typical to phosphonium derivatives of oxyalkylphosphines. 

E/Z stereochemistry of a,/ -ethylenic phosphonium derivatives is essentially governed by steric factors apart from when there is extra stabilization, as is the case with betaines87. Z->E isomerization may be performed using sterically crowded amines (so that any Michael-type addition would be prevented)192,193. Spectrometry allows the progress of the reaction to be observed (Section I.C). 

Phosphonium derivatives of aza crown ethers were effective as neuromuscular blocking agents in both in vitro and in vivo experiments198 Analgesic properties were also found199. 

A convenient route to the 1,3-selenazole nucleus uses a polyfunctional reagent such as the vinylphosphonium salt (110), which with sodium hydrogen selenide gives the ylide (111) (Scheme 33). Cyclization of (111) yields the phosphonium derivative (112). A variety of compounds have been prepared by this method [182-184],... 

Other most successful durable treatment is based on tetrakis (hydroxymethyl) phosphonium derivatives. Very well-known brand marketed as Proban CC (Rhodia, previously Albright Wilson) involves padding of tetrakis (hydroxymethyl) phosphonium chloride (THPC) urea solution onto the cotton fabric, curing with ammonia in a specially designed reactor to generate a highly cross-linked three-dimensional polymer network. The fabric is then treated with hydrogen peroxide, which converts P3+ to the P5+ state. The reactions are shown in Scheme 24.2. Other similar commercial product is Thor s Aflammit P. In literature many combinations of tetrakis (hydroxymethyl) phosphonium derivatives with other salts have been reported,50 but the most successful so far has been the THPC-urea-NH3 system discussed earlier. 

Treatment of P-oxido ylides with electrophiles other than proton donors provides a route to stereospecific trisubstituted alkenes. For example, trapping the P-oxido phosphonium ylide B with formaldehyde (generated from paraformaldehyde) leads to dioxido phosphonium derivative D to yield, after elimination of triphenylphosphine oxide, the trisubstituted allylic alcohol... 

Formally related reagents for peptide synthesis are uronium derivatives such as (7.86) (Knorr et al., 1989 Chen and Xu, 1992). Like the phosphonium derivatives, this type of reagent causes very little enantiomerisation. 

Minami 1, Inada T, Sasaki R et al (2010) Tribo-chemistry of phosphonium-derived ionic liquids. Tribol Lett 40 225-235... 

Enhancer for 1,2-dioxetane derivatives is composed of hydrophobic compound and fluorescent dye. We tested a variety of enhancers and found a better enhancer for this substrate, namely tetra-alkyl phosphonium derivative as hydrophobic... 

A significant increase in the volume of published work in the area of phosphine and related chemistry has been noted. Worthy of special mention are the first example of chiral resolution of a secondary phosphine which is chiral at phosphorus and, for followers of chemical fashion, inevitably the first phosphonium derivative of Buckminsterfullerene (C ) has been described. 

The substitution of the chloro group of CMF with triphenylphosphine gives a phosphonium derivative 38 which reacts with base to give annulene 1,4-oxide macrocycles 39 [143] and conjugated poly(2,5-furanylvinylene) polymers 40... 

In more recent years phosphonium derivatives such as Bates reagent (Bates et ai. 1975)... 

These highly air-sensitive complexes apparently owe their high stability to the incorporation of chelating phosphorus yhde ligands. The neutral complexes show dynamic behavior in solution producing dimeric, trimeric and polymeric species in addition to the monomers. This could be demonstrated with the di-tert-butyl phosphonium derivative of lutetium (Schumann and Reier, 1982a) ... 

In 2009, the phosphonium-derived catalyst 122 was utilized by Maruoka and co-workers [66]. The group aimed to construct chiral quaternary carbon centers and set out to explore the scope of these particular phase-transfer catalysts, since they successfully employed chiral quaternary phosphonium salts before. The catalyst... 

Scheme 5.49 Construction of chiral quaternary carbon centers with phosphonium-derived catalyst 122...

Amino-substituted (quasi-phosphonium) derivatives are produced in reaction (6.373) and by reaction of tertiary phosphines with chloramine or hydrazoic acid (6.104,6.105), or by the reaction of phosphonous diamides with chloramine or alkali metal halides (7.196). 

The highly significant stereochemical implications of the Wittig reaction are discussed in Chapter 3.3. Aza-Wittig and Phospha-Wittig reactions are known (6.457, 6.458). Betaine-like structures (3.112) are found in some quasi-phosphonium derivatives. 

Phosphonium derivatives may be made directly by reacting ethylene dibromide with an appropriate phosphine. Either cis or trans isomers may be obtained, depending upon whether the starting material is a meso or a racemic phosphine (6.840, 6.841). 

Dehydrohalogenation may be carried out directly upon phosphonium derivatives in the method due to Mathey [52]. 

Another area of interest in recent years is that of dendritic structures (dendrimers) to which P compounds have made a significant contribution. Following the discovery in 1990 of dendrimers based on phosphonium derivatives, various phosphorus compounds have now been obtained. These contain P groups which act as initiator cores or as subsequent branching points (12.254), (8.356) [102-106]. 

The reactivities of analogous aminium and phosphonium derivatives are essentially equivalent. However, aminium-based reagents can, if used inappropriately, cause capping of resin-bound amino groups through formation of N-terminally guanidinated peptides 23 (38). This side-reaction occurs most... 

The elimination of triphenylphosphine oxide from the phosphonium derivatives (106) (Scheme 23) of tu-hydroxyacids has been shown to give macrolides, but yields are variable. 

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