2,6-Diphenyl-4- phenoxide

Fig. 4. Results of an X-ray analysis of 2,6-diphenyl-4-(4 bromophe-nyl)-N-(2,6-diphenyl-4-phenoxide)-pyridinium-betaine-mono-ethanolate(20).

Radical cyclization to triple bonds is used as the key step for the synthesis of oxygen heterocycles. This methodology can benefit from a Lewis acid, such as aluminum fns(2,6-diphenyl phenoxide) (ATPH), which forms a complex with the... 

The synthesis of oxygen heterocycles in which cyclization onto a pendant alkyne is a key step has also been achieved. Reaction (7.36) shows an example of iodoacetal 29 cyclization at low temperature that afforded the expected furanic derivative in moderate Z selectivity [47]. A nice example of Lewis acid complexation which assists the radical cyclization is given by aluminium tris(2,6-diphenyl phenoxide) (ATPH) [48]. The (3-iodoether 30 can be com-plexed by 2 equiv of ATPH, which has a very important template effect, facilitating the subsequent radical intramolecular addition and orienting the (TMS)3SiH approach from one face. The result is the formation of cyclization products with Z selectivity and in quantitative yield (Reaction 7.37). 

A general mediod for the synthesis of aryloxy(chloro)neopentylidene-tungsten complexes involves the reaction of WCl4(OAr)2 (OAr = 2,6-disubstituted phenoxide) [20] with 1 equiv or 1.5 equiv of MgNp2(dioxane) (Np=CH2C(CH3)3) [11, 21] (Scheme 1). The reaction proceeds via a double (or triple) kylation of tungsten followed by an a-H abstraction and elimination of neopentane [22]. In the particular case of the 2,6-diphenyl-phenoxide complexes, the activation of m ortho C-H bond in one of the phenyl substituents of the aryloxide ligands leads to the elimination of HCl with the formation of a cyclometalated compound (Scheme 2) [23, 24]. 

Nitrodiphenyl ether has been prepared by heating p-nitro-chlorobenzene with potassium phenoxide and phenoD and by the nitration of diphenyl ether. ... 

A variant for the synthesis of diaryl ethers—e.g. diphenyl ether 9, where an aryl halide and a phenoxide are reacted in the presence of copper or a copper-(I) salt, is called the Ullmann ether synthesis. ... 

Stepwise displacement of phenoxide from diphenyl carbonimidates (e.g., 2) is also possible, as in Scheme 3.6... 

Potassium 3,5-dinitro-2(l-tetrazenyl)phenoxide, 2249 Potassium 2,6-dinitrotoluene, 2717 Potassium diperoxomolybdate, 4654 Potassium diperoxoorthovanadate, 4662 Potassium O, (9-diphenyl dithiophosphate, 3475 Potassium dithioformate, 0377 Potassium ethoxide, 0857... 

The available rate data for the substitution reactions of phenol, diphenyl ether, and anisole are summarized in Table 5. The elucidation of the reactivity of phenol is hindered by its partial conversion in basic media into the more reactive phenoxide anion. Because of the high reaction velocity of phenol and the even greater reactivity of phenoxide ion the relative rates are difficult to evaluate. Study of the bromination of substituted phenols (Bell and Spencer, 1959 Bell and Rawlinson, 1961) by electrochemical techniques suitable for fast reactions indicates the significance of both reaction paths even under acidic conditions. 

The solvatochromic effects on UV/visible spectra of certain solutes are so large, that they can conveniently be employed as probes for certain solvating properties of the solvents. Those that have enjoyed widespread application in this capacity are discussed in Chapter 4. They include 2,6-diphenyl -4-(2,4,6-triphenyl-l-pyridino)-phenoxide, 4-methoxynitrobenzene, 4-(dimethylamino)-nitrobenzene, for the estimation of the polarity of solvents, acetylacetonato-N,N,N, N -tetramethylethylenediamino-copper(II) perchlorate, 4-nitrophenol, and 4-nitroaniline, for the estimation of the electron pair donicity of solvents, 4-carboxymethyl-l-ethylpyridinium iodide, 4-cyano-l-ethylpyridinium iodide, and bis-c/.v-1, lO-phenanthrolinodicyano-iron(II) for the estimation of the hydrogen bond donation abilities of solvents (Marcus 1993). 

Diphenyl Tellurium Bis[2-(uicthylcnciminoinethyl)-phenoxide]0.23 g (10 mmol) of sodium is reacted with 1.34 g (5 mmol) of Ar,7V -bis[2-hydroxybenzylidene]ethylenediamine in absolute methanol and then the methanol is evaporated under reduced pressure. The residue is suspended in 75 ml of benzene, the suspension is heated under reflux, and a solution of 1.76 g (5 mmol) of diphenyl tellurium dichloride in 75 ml of benzene is added dropwise. The mixture is heated under reflux for 4 h, precipitated sodium chloride is filtered off, and the filtrate is concentrated. Petroleum ether (b. p. 60-80°) is added to Ihe concentrate to precipitate the orange colored product which is recrystallized from benzene/petroleum ether) yield 1.8 g (67%) m.p. 110°. Similarly prepared were ... 

Diaryl tellurium benzenesulfonimide and 1,4-dihydroxybenzene reacted in dry chloroform to give diaryl 2,5-dihydroxyphenyl telluronium salts. With diphenyl tellurium arenesulfon-imides a diphenyl tellurium phenoxide was also isolated3. 

Average value obtained using 2,6-diphenyl-4-(2,4,6-triphenyl-l-pyridinio)phenoxide, 1-hexadecyl-4-[(oxocyclohexadienylidene)ethylidene]-l,4-dihydropyridine, l-hexadecyl-5-hydroxyquinoline and l-hexadecyl-6-hydroxyquinoline, average deviation <9 % calculated from [47d]. Abbreviations SDS = sodium dodecyl sulfate DBS = dodecyl benzenesulfonate CTAC = hexadecyltri-methylammonium chloride CTAB = hexadecyltrimethylammonium bromide DTAC = dodecyl-trimethylammonium chloride DTAB = dodecyltrimethylammonium bromide DHP = dihexadecyl phosphate DDDAB = didodecyldimethylammonium bromide DMPC = dimyristoylphosphati-dylcholine DPPC = dipalmitoylphosphatidylcholine POPC = l-palmitoyl-2-oleoylphosphati-dylcholine PCA = phosphatidic acid. 

Refluxing diphenyl tellurium oxide with bis[2-(methyleneiminomethyl)-phenol] in benzene yields the diphenyl tellurium phenoxide. ... 

Diphenyl tellurium oxide and imines prepared from 2-hydroxybenzaldehyde and ethy-lenediamine reacted in benzene to produce a diphenyl tellurium phenoxide. ... 

Figure 108. The Absorption Spectrum of REICHARDT s Dye [2,6-diphenyl-4-(2,4,6-tri-phenyl-l-pyridinio)phenoxide] at 25 °C. The formula of the dye is shown in the lower left comer of the diagram.

Diphenyl terephthalate (DPT) was prepared by interfacial reaction of sodium phenoxide in water and terephthaloyl chloride (TPC) in methylene chloride, using benzyl triethylammonium chloride as catalyst, followed by washing with hot water and recrystallization from toluene. The yield was usually 90% or higher. 

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