Triphenylphosphine and

An elegant synthesis method which is specific to sulfone polymers containing phenyl—phenyl linkages (such as PPSF) is the nickel-catalysed coupling of aryl dihahdes. The scheme for this synthesis involves a two-step process. First, an aromatic dihaUde intermediate is formed which carries the backbone features of the desired polymer. This aromatic dihahde intermediate is then self-coupled in the presence of sero-valent nickel, triphenylphosphine, and excess sine to form the biphenyl- or terphenyl-containing polymer. AppHcation of this two-step scheme to PPSF can be depicted as follows ... 

Inter and Intramolecular nucleophiKc displacement o< alcohols wHh inversion by means of cHethyi azo cartMxylate (DEAD)-triphenylphosphine and a nucleophile. Also dehydration, esterification of alcohols or alkylallon of phenols,... 

Eastman Kodak Co. white label triphenylphosphine and Matheson Co. methyl bromide were used. Triphenylphosphine is available from the Metal and Thermit Corp., Rahway, New Jersey. 

More recent examples have employed a milder reagent system, triphenyl-phosphine and dibromotetrachloroethane to generate a bromo-oxazoline, which is subsequently dehydrohalogenated. Wipf and Lim utilized their method to transform intermediate 11 into the 2,4-disubstituted system of (+)-Hennoxazole k Subsequently, Morwick and coworkers reported a generalized approach to 2,4-disubstituted oxazoles from amino acids using a similar reagent combination, triphenylphosphine and hexachloroethane. ... 

Reaction of lithium 2,5-dimethylpyrrolate ion with [RhCl(CO)2]2 leads to formation of 84 (88PAC1193 90P1503). This is the first example of the mixed mode, when the ti N) and ti (C=C) coordination are realized simultaneously. Nucleophilic addition of triphenylphosphine and triphenylarsine gives 85 (E = P, As). The iridium analogs of 84 and 85 have also been synthesized. 

Complex 105 enters the pyrazoleAriphenylphosphine ligand substitution reaction with PPha to give 108 (910M3123). Further reaction with triphenylphosphine and silver tetrafluoroborate gives the heterodinuclear complex 109 (94IC2196). 

The N-coordinated compound [AuCljL] (L= l-ethyl-2-phenylimidazole) with silver tetrafluoroborate gives the cycloaurated species 102, which on further reaction with triphenylphosphine and sodium tetrafluoroborate or ammonium hexafluorophosphate forms the cationic complexes 103 (X = BF., PF,) (00JCS(D)271). 

The mechanistic pathway" " can be divided into three steps 1. formation of the activating agent from triphenylphosphine and diethyl azodicarboxylate (DEAD) or diisopropyl azodicarboxylate (DIAD) 2. activation of the substrate alcohol 1 3. a bimolecular nucleophilic substitution (Sn2) at the activated carbon center. 

The conversion of an alcohol to an amine can be achieved in a one-pot reaction the alcohol 1 is treated with hydrazoic azid (HN3), excess triphenylphosphine and diethyl azodicarboxylate (DEAD). The initial Mitsunobu product, the azide 14, further reacts with excess triphenylphosphine to give an iminophosphorane 15. Subsequent hydrolytic cleavage of 15 yields the amine—e.g. as hydrochloride 16 ... 

The following procedure is described in U.S. Patent 3,475,407. A solution of 50 g of lincomycin hydrochloride, 120 g of triphenylphosphine, and 500 ml of acetonitrile in a 3 liter flask equipped with a stirrer was cooled in an ice bath and 500 ml of carbon tetrachloride was added in one portion. The reaction mixture was then stirred for 18 hours without addition of ice to the cooling bath. The reaction was evaporated to dryness under vacuum on a 50° to 60°C water bath, yielding a clear, pale yellow viscous oil. An equal volume of water was added and the mixture shaken until all of the oil was dissolved. The resulting suspension of white solid (03PO) was filtered through a sintered glass mat and discarded. The filtrate was adjusted to pH 11 by addition of 6N aqueous sodium hydroxide. A solid precipitated. 

Figure 4.1-13 Comparison of the experimental without (—) and with (—) triphenylphosphine at (solid line) and fitted (dashed line) (a) EXAFS 80 °C and in the presence of triphenylphosphine and (b) pseudo-radial distribution functions and reagents at 50 °C for 20 min (—). Repro-...

In the presence of triphenylphosphine and four equivalents of chloride, (1-butyl-3-methylimida2olylidene)bis(triphenylphosphine)palladium(II) chloride is formed (Scheme 6.1-4). 

Like tellurophene the fused compound forms 1,1-addition products with halogens (73BSF2468), but further bromination of such a 1,1-dibromo species gave 1,1,2-tribromobenzo[/>]tellurophene, which was able to be reduced to 2-bromobenzo[b]tellurophene. The 3-chloro and -bromo compounds were isolated following reaction of triphenylphosphine and the appropriate carbon tetrahalide with 2,3-dihydro-3-oxobenzo[b]telluro-phene (80BSB763). 

Cydization of P-hydroxy-a-amino esters under Mitsunobu reaction conditions is an alternative approach to aziridine-2-carboxylic esters [6b, 13-16], In this case the P-hydroxy group is activated by a phosphorus reagent. Treatment of Boc-a-Me-D-Ser-OMe 13 (Scheme 3.5) with triphenylphosphine and diethyl azodicarboxylate (DEAD), for example, gave a-methyl aziridinecarboxylic acid methyl ester 14 in 85% yield [15]. In addition to PPh3/DEAD [13b, 15], several other reagent combi-... 

Trioxymethylene, condensation with nitromethane, 41, 67 Triphenylcinnamylphosphonium chloride, from triphenylphosphine and cinnamyl chloride, 40, 36... 

Void-free phenolic-epoxy networks prepared from an excess of phenolic novolac resins and various diepoxides have been investigated by Tyberg et al. (Fig. 7.37).93 -95 The novolacs and diepoxides were cured at approximately 200°C in the presence of triphenylphosphine and other phosphine derivatives. Network densities were controlled by stoichiometric offsets between phenol and... 

Phosphines behave similarly, and compounds of the type R3P and R4P X can be so prepared. The reaction between triphenylphosphine and quaternary salts of nitrogen heterocycles in an aprotic solvent is probably the best way of dealkylating the heterocycles, for example, ... 

The 1,1-dimetallic compounds, R2C(SnMe3)ZnBr, were oxidized by dry air at —10 to 0°C in the presence of Me3SiCl to give aldehydes or ketones, R2C=0. In a related indirect method, arylthallium bis(trifluoroacetates) (prepared by 12-21) can be converted to phenols by treatment with lead tetraacetate followed by triphenylphosphine, and then dilute NaOH. Diarylthallium trifluoroacetates undergo the same reaction. ... 

B. Nucleophilic Attack on Halogen.- (/ )-( +)-2,2-dimethylpropan( H)ol has been converted to the chloride with inversion of configuration using triphenylphosphine and carbon tetrachloride. The corresponding reaction using carbon tetrabromide gave the bromide with considerable racemiza-tion. ... 

The use of triphenylphosphine and 2,2 -bipyridyl disulphide in oxidation-reduction condensations has been extended to the phosphorylation of alcohols and phosphates, and to the preparation of 5 -(2-pyridyl) phosphorothioates (60) which have been used for the synthesis of pyrophosphates (see Chapter 6, Section 1). 

C. Miscellaneous.—Treatment of the phosphonium bromide (114) with one equivalent of butyl-lithium gave triphenylphosphine and benzylidene-methylamine via a Hofmann-like decomposition, whereas reaction with two equivalents of butyl-lithium resulted in the production of butyltriphenyl-phosphonium bromide. ... 

Pyran-2-ones were obtained in low yield on heating /8-diketones, e.g. (52), with the ester phosphorane (53) under severe conditions. In refluxing benzene the cyclopropenones (54) with the phosphoranes (55) gave triphenylphosphine and the pyran-2-ones (58) (50%). At room... 

The seven-membered exocyclic phosphorane (111) with the fluorene-aldehyde (112) gave triphenylphosphine and the aldehyde (114) instead of the expected olefin. Compound (114) could have been formed as shown, the phosphorane functioning as a base to generate the anion (113). 

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