Diphenyl phosphorane

Chlor-dibrom-diphenyl-phosphoran setzt sich mit 2-Amino-phenolen in Gegenwart von drei Molen Triethyl-amin in Benzol zu cyclischen Phosphinsiiure-ester-imiden um die Ausbeute z.B. an 2,2-Diphenyl-(benzo-1,3,2-Xs-oxuzuphusphul) betragt 537o 101 ... 

The Wittig reaction of diphenyl cyclopropenone with the phosphorane 68 failed to give the methylene cyclopropene instead a hydrocarbon of probable structure 67 was obtained71. ... 

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. 

In 1981, Appel et al. postulated the transient formation of the (diphenyl-phosphino)(trimethylsilyl)carbene 2e to explain the formation of the phos-phaalkene 4e, in the thermolysis of the P-chloromethylene phosphorane 3e.29 At that time, the authors did not recognize the carbene character of 2e and simply named the intermediate a A5-phosphaalkyne. 

Phosphorane Diphenyl-trifluoro-ElOa, 501 (Educt), S07/515 (P-CI -> PF3) ElOb,. 112 (Educt)... 

Die Umsetzung eines acylierten Diphenyl-ethoxy-methylen-phosphorans mit Benzyl-bromid liefert in quantitativer Ausbeute einen phosphorylierten Enolether, vermutlich iiber eine Alkoxyphosphoniumsalz-Zwischenstufe, die nach Art der Michaelis-Arbu-sov-Reaktion desalkyliert wird389 ... 

Alkyl-diphenyl-phosphanoxide mit weiteren Acceptorsubstituenten am Alkyl-Rest lassen sich in Methylen-phosphorane umwandeln. So liefert z.B. das aus Bis-[diphenylphos-phinyl]-methan und Natriumhydrid in Dimethylsulfoxid erhaltliche Carbanion bei der Alkylierung mit Alkylbromiden nicht das zu erwartende Kohlenstoffalkylierungspro-dukt (s. Bd. XII/1, S. 164), sondern ein Alkoxy-diphenyl-(diphenyIphosphinyl-methylen )-phosphoran 459. 

Bis-[diphenylphosphoryI]-amin (90%) wird auch durch Reaktion von Diphenyl-tri-chlor-phosphoran mit Ammoniumchlorid und partieller Hydrolyse des Primaraddukts mit Amcisensaure erhalten806 ... 

Beim Erhitzen von Diphenyl-trichlor-phosphoran mit N-(Perfluoralkyl-iminocarbonyl)-perfluorarylamidinen auf 97-100° entstehen unter Chlorwasserstoff-Abspaltung in guter Ausbeute 4,6-Bis- [perfluoralkyl] - 2,2-diary 1-1,3,5,2k5- triazaphos pho-... 

Mit N-Cyan-trichloressigsaure-amidin und Diphenyl-trichlor-phosphoran wird das 6-Chlor-2,2-diphenyl-4-trichlormethyl-l,3,5,2Xs-triazaphosphorin zu 87% erhalten"20. 

Difluor-diphenyl-(2-methyl-piperidino)-phosphoranS J Unter Stickstoff werden 8,5 g (50 mmol) (2-Methyl-pi-peridino)-trimethyl-silan unter Riihren bei 50° zu 12,2 g (50 mmol) Diphcnyl-trifluor-phosphoran gegeben. Nach 2 Stdn. Erhitzen auf 80 wird der Kolbenriiekstand destilliert Ausbeute 14,7 g (93%) Sdp. 16670,05 Torr (6,67 Pa). 

Diphenyl-trifluor-phosphoran iiberfuhrt Alkohole glatt in die zugehorigen Alkylfluori-de74 ... 

Arbeitsvorschrift Zur Ldsung der Hexafluoraceton-benzoylimine in wasserfreiem Hexan wird bei 0° die aqui-molare Menge Diphenyl-methoxy-phosphoran gctropft. Man laBt mehrcre Stunden bei 0° stehcn, trennt das aus-gefallene Produkt ab und kristallisiert aus Hexan. 

Dimethyl-2,4-diphenyl-2,2,4,4-tetrafluor-aus Heptamethyldisilazan und Phenyl-tetra-fluor-phosphoran E2, 860/861... 

Barton et al. have described a particularly mild method for the conversion of ketoximes into ketimines (aldoximes give nitriles instead). A mixture of tributylphosphine and diphenyl disulfide reacts under anhydrous conditions with ketoximes, probably by way of the phosphorane intermediates shown in Scheme 20, to give ketimines. The reagent is effectively a self-drying one since it reacts irreversibly with water. Chlorodiphenylphosphine is also capable of deoxygenating ketoximes with this reagent... 

C,H,N, Benzene, 2-isocyano-l,3-dimethyl-, iron complexes, 26 53 57 C,H jN, Benzenemethanamine, N,N-di-methyl-, lithium complex, 26 152 Iutetium complex, 27 153 palladium complex, 26 212 QHijP, Phosphine, cthylmethylphenyl-, lithium complex, 27 178 C,H,3P, Phosphorane, dimethylmethylene-diphenyl-, uranium complex, 27 177 C,H P, Phosphine, triisopropyl-, rhodium complex, 27 292 tungsten complex, 27 7 C,Hj7PSi3, Phosphine, tris(trimethylsilyl)-, 27 243... 

Bicvclic and Tricyclic Phosphoranes. - The reaction of phosphorocyanatidites (96ab) with alkylidene acetamide (97) proceed via the common intermediate (98) to form either (99, R= Me) by reaction with a second mole of (97) or (100) by dimerisation.30,31 An analogous dimerisation product (102) is also obtained with diphenyl carbodiimide (101)3 and the reactions of alkynylphosphonates with (101) are reported in the same paper. 

Amino Acids and Peptides. - Wasserman s method of one-carbon homologation of carboxylic acids to give a-ketocarboxylates involves reaction with cyanomethylenetriphenyl-phosphorane followed by ozone (Scheme 24) and has been used as a key step in a chemo-enzymatic synthesis of isotopically labelled L-valine, L-isoleucine, and o/fo-isoleucine. Alkylation of the carbanion derived from the imino-substituted methylphosphonate diphenyl ester (186) with indol-3-ylmethyl bromide followed by appropriate deprotection has been used to prepare the phosphonate analogue (187) of tryptophan (Scheme 25). The deprotected analogue (188) and derived peptides show activity as inhibitors of chymotrypsin. Two approaches to solid phase Wadsworth-Enunons reactions which have applications in combinatorial chemistry have been reported. In one diethylphosphonoacetamide is bound to PEG-PAL resin via a peptide link, while... 

Further evidence for a biphilic insertion mechanism is derived from a study of the reaction of the bicyclic phosphoramidites (115) and (116) with diethyl peroxide to form (117) and (118), respectively. The strained 1-phosphabi-cyclo[3.3.0]octane (115) reacts much faster than its l-phosphabicyclo[4.4.0]-decane analogue (116), but the opposite reactivity is found towards diphenyl disulphide. At room temperature (116) produced (120) within seconds, presumably via an intermediate phosphonium salt, whereas (115) gave (119) [S 3ip = —19 p.p.m.] after 1 h at 58 °C. As mentioned earlier, the latter appears to be the only phosphorane reported so far with two exocyclic P-S bonds. 

Na2Mo02 2H2O) and sodium methylamino- or ethylamino-dithiocarbamate. In THF, the Mo compound is treated with various simple diazoalkanes, e.g., phenyl-, diphenyl-, methylphenyl-, and secondary alkyl-diazomethanes. In this reaction (10-21), metalloazines of type 10.54 are formed as yellow crystals in a broad spectrum of yields up to 99%. The ratio of (Z)- to ( )-isomers was determined based on NMR spectroscopy. These metalloazines behave as active carbonyl equivalents in a Wittig-type reaction with phosphoranes (10-22) and form the corresponding ethene derivatives. 

The reaction of bicyclic phosphoramidites with alcohols offers a simple route to hydridophosphoranes. In particular the oxidative addition of a variety of alcohols (ROH) or phenol (PhOH) with bicyclic phosphoramidites of type (107) give a wide range of bicyclic phosphoranes of type (108) with the P-H bond in an equatorial position. A number of addition reactions with activated double (e.g. fumaric ester) and triple (e.g. acetylene dicarboxylic ester) bonds arc also dcscribcd. The reaction of hydridophosphoranes (109) with alcohols (1 lOa-0 takes a further step in the presence of diphenyl disulphide to generate the alkoxylated products (llla-f). ... 

PC9H13, Phosphorane, dimethylmethylene-diphenyl-, uranium complex, 27 177 PC9H21, Phosphine, triisopropyl-, platinum complex, 28 120 rhodium complex, 27 292 PC9H21, Phosphine, triisopropyl-, tungsten complex, 27 7... 

Other studies involving kinetics include a complex model for the synthesis of 0,0-dimethyl phosphorochloridothioate, the anilinolysis of diphenyl thiophosphinic chloride and of dimethyl and diethyl chloro(thiono) phosphates,and finally the isomerization of anti-apicophilic penta-coordinate phosphoranes having a chelating O-equatorial substituent. ... 

---