Triphenyl phosphorane

Ethyl (triphenylphosphoranylidene)acetate is available from FIuka AG and Trldom Chemical Inc. under the name (ethoxycarbonylmethylene)triphenyl-phosphorane and from Aldrich Chemical Company, Inc. under the name (carbethoxymethylene)triphenylphosphorane. The reagent may be prepared from triphenyl phosphine and ethyl bromoacetate by the following procedure. ... 

Phosphorane (dichloromethylene) TRIPHENYL 1, 46, 33 Phosphorous triamide, hexamethyl, 46, 42... 

Phenylcyclopent[c]azcpine (33a) and 6,7-fused cyclopentazepines 33b-d are formed in moderate yields in a one-pot, two-stage process involving initial condensation of triphenyl-[(l-phenylvinyl)imino]phosphoranes 32 with 6-(dimethylamino)fulvene-2-carbaldehyde (30), followed by an intramolecular aza-Wittig reaction of the iminophosphorane with the pendant aldehyde function.5 The method fails with the unsubstituted vinylphosphorane 32 (R1 = R2 = H). 

Triphenyl[(pheny1imino)ethylidene]phosphorane (91) reacts with... 

The study of [4.4.0] ring systems has resulted primarily from the study of various other aspects of phosphorus chemistry. An investigation into the effect of nitrogen donor action on the increase in coordination at phosphorus in a series of oxyphosphoranes led Holmes and co-workers <1998IC4945> to compounds 24 and 25. The compounds were fully characterized by NMR spectroscopy and X-ray diffraction. Compound 24 was heated for 30 min at 140°C in an NMR tube. The reaction was followed by 31P NMR spectroscopy which indicated that conversion to a phosphorane 26 and a small amount of phosphate had taken place (Equation 4). The pentaoxyphosphorane 25 was successfully produced via an oxidative addition reaction between the diol 27 and triphenyl phosphate in the presence... 

Finally, a reaction should be mentioned in which a nucleophile gives support to another reacting species without appearing in the final product. Diphenyl cyclopropenone interacts with 2,6-dimethyl phenyl isocyanide only in the presence of tri-phenylphosphine with expansion of the three-ring to the imine 344 of cyclobutene-dione-1,2229,230 Addition of the isocyanide is preceded by formation of the ketene phosphorane 343, which can be isolated in pure formss 231 it is decomposed by methanol to triphenyl phosphine and the ester 52. 

Phosphorane, (dichloromethylene) TRIPHENYL-1, 46, 33 Phosphorus pentachloride, for conversion of D,L-10-camphorsulfonic acid to acid chloride, 46,14 reaction with styrene, 46, 99 Photolysis of substituted stilbenes to phenanthrenes, 46, 91... 

IV. OTHER ORGANOLITHIUM COMPOUNDS A. Lithiation of Triphenyl((trimethylsilyl)imino)phosphorane, Ph3P=NSiMe3... 

Involvement of 625 in a Wittig reaction with 4-carboxybutyl(triphenyl)phosphorane dissolved in dimethyl sulfoxide generates a mixture of double bond isomers rich in 623. 

The 2-vinyl derivatives 256-258 were obtained by standard Wittig methylenation of the corresponding aldehydes <1996GCC888, 1997CCC1468> (Equation 5) with methylene(triphenyl)phosphorane in 54-78% yield after chromatographic purification. 

Imino-ethenyliden)-phosphorane wie l-Pheny]imino-2-(triphenyl-phosphoranyliden)-ethen I lagern sich an NH-Bindungen an und bilden Phosphorane II, die mit Aldehyden weiter zu einer Vielzahl von Alkenen III kondensieren. Mit Benzimidazol erhalt man z. B.527 ... 

Kohlensaure-anilid-(2-benzoyl-hydrazid) reagiert mil Dichlor-triphenyl-phosphoran/Triethyl-amin iiber Benzonitril-(anilinocarbonyl-imin) in einer 1,5-Elektrocyclisierung zu 2-Anilino-5-phenyl-1,3,4-oxadiazol (87% Schmp. 21 4 2 1 5 )420 ... 

Ethoxycarbonyl-l-hydroxy-benzimidazol wird offensichtlich auch bei der Umsetzung von Benzofurazan-l-oxid mit (Ethoxycarbonyl-methylen)-triphenyl-phosphoran als Zwischenpro-dukt durchlaufen nach weiterer Reaktion mit (Ethoxycarbonyl-methylen)-triphenyl-phospho-ran wird letztlich ein Gemisch aus J-Ethoxy-2-ethoxycarbonyl- und 2-Ethoxycarhonyl-henz-imidazol erhalten299. 

Eine neuere Methode arbeitet mit Bis-[2,2,2-trifluor-ethoxy]-triphenyl-phosphoran als Reagenz (aus Dibrom-triphenylphosphoran und Natrium-2,2,2-trifluor-ethanolat in Ether bei 0°) und ergibt gute Ausbeuten an sekundaren Aminen3 ... 

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