Phosphonium alkyltriphenyl

Fluoroolefins may he prepared by the reaction of Wittig reagents and other pho sphorus-containtng y tides with fluorinated carbonyl compounds. (A discussion of the fluorinated Wittig reagents or other fluonnated phosphorus reagents with nonfluorinated carbonyl compounds is on page 581.) Tnphenylphosphoranes, derived from alkyltriphenyl phosphonium salts, react with 1,1,1-trifluoroacetone [3/] or other trifluoromethyl ketones [32, iJ] (equation 26) (Table 10). 

The fluorescence of a range of polycyclic aromatic hydrocarbons is found to be quenched in the presence of alkyltriphenyl-phosphonium salts via electron-transfer from the hydrocarbon to... 

Wittig reactions.1 Potassium carbonate can function as a solid-liquid transfer catalyst for Wittig reactions of aliphatic or aromatic aldehydes with alkyltriphenyl-phosphonium bromides in dioxane containing a trace of water. K2CO3 is superior to NaOH because it does not catalyze aldol condensation. As expected, the (Z)/(E) ratio is 70 30. 

Triphenylphosphine, (CgHs P Reacts with primary alkyl halides to yield the alkyltriphenyl-phosphonium salts used in Wittig reactions (Section 19.11). 

Electrochemically-promoted reversible interconversion of alkyltriphenyl-phosphonium salts and the related ylides has been shown to occur in the presence of benzophenone oxime O-methyl ether as a mediator, providing an example of electrochromism. Nucleophilic addition to vinylphosphonium salts has again been widely used as a means of generating ylides, and for the synthesis of heterocyclic systems" New developments include the catalysis of addition of... 

The order found can be ascribed mainly to differences in solvation energies of anions in organic solvents and water and applies to ammonium as well as alkyltriphenyl [5] or tetraphenyl phosphonium salts [6], at least in dilute solutions. 

The Wittig reaction, using deprotonated alkyltriphenyl phosphonium salts, converted aldehydes and ketones to alkenes. 

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