Phosphine, triphenyl oxides

Triphenylphosphine oxide hydrobromide Phosphine oxide, triphenyl-, compd. with hydrobromic acid (1 1) (9) (13273-31-9)... 

Library Wiley6 Spectrum 145586 Name Phosphine oxide, triphenyl... 

The liberated iodine may be titrated using std thiosulfate soln, or, in trace analysis, detd by spectrophotometric methods. Other reducing agents commonly used in peroxide analysis are hydriodic acid, ferrous, titanous, stannous, and arsenious ions. Also (recently), triphenylphos-phine, which is oxidized to triphenyl phosphine oxide. The excess triphenyl phosphine may be detd gravimetric ally, tit rime trically, or spectro-photometrically... 

These polymers show lower water uptake than the analogous sulfonated poly(arylene ether sulfone) materials, possibly suggesting some interaction between the aromatic nitrile and sulfonic acid. The phosphine oxide functional moiety could also be used as a compatibilizer with other materials. Sulfonated poly(arylene ether phosphine oxide sulfone) terpoly-mers have been prepared both with sulfonated triphenyl phosphine oxide and with triphenyl phosphine oxide with 3,3 -disulfonate-4,4 —dichlorodiphenyl sulfone as the sulfonic acid bearing monomer. Block copolymers containing phosphine oxide appear to avoid the ether—ether interchange that results when non—phosphine oxide blocks are utilized, and this is being further pursued. ... 

A somewhat different problem occurs in the question of the structure of, say, the phosphine oxides, the phosphine methylenes or the sul-phoxides. Again in a 3s3p framework the structure of triphenyl phosphine oxide must be written with the oxygen attached by a conventional coordinate link. On the other hand the use of d-orbitals allows the removal of the excess negative charge on the oxygen atom by the formation of a t-bond (Fig. 3). 

Cyclohexene annelation.1 Reaction of ketone enolates with 2 equiv. of this salt results in two sequential Michael reactions to give a cyclohex-enyl(triphenyl)phosphonium bromide, which can be hydrolyzed to a cyclohex-enyl(diphenyl)phosphine oxide.1... 

However, they encountered a problem with the purification of 220 from the by-product, triphenyl phosphine oxide and therefore developed an alternative route for the cyclization. Thus, treatment of 219 in dichloromethane with 1.5equiv of methanesulfonyl chloride and 3equiv of TEA gave traces of product 220 along with O-mesylated intermediate 221 as the major product (Equation 27). 

Preparation of alkyldiphenylphosphine oxides. General procedure from phospho-nium salts. Triphenyl phosphine is heated under reflux with an excess of alkyl halide. The precipitated phosphonium salt is filtered off, washed well with ether, and then heated with 30 per cent w/w aqueous sodium hydroxide (c. 4 ml/g) until all the benzene has distilled out. The mixture is cooled and extracted with dichloromethane, and the extracts are dried (magnesium sulphate) and evaporated to dryness. In this way ethyldiphenylphosphine oxide is obtained from triphenyl phosphine (65.6 g, 0.25 mol) and iodoethane (42.9 g, 0.275 mol) in dry toluene (250 ml) to give first the phosphonium salt (102.4 g, 97.9%) after 3.5 hours, from which the phosphine oxide is obtained as needles (53.2 g, 92.5%), m.p. 123-124 °C (from ethyl acetate) p.m.r. 5 (CDC13, TMS) 1.9-13 (m, 10H, Ph2PO), 2.3 (m, 2H, CH2) and 1.2 (dt, 3H, JHm, = 7 Hz, JMeP = 17 Hz, Me). 

The [NdL4(C104)2]C104 complex has both ionic and bound perchlorate [218]. With L = triphenyl arsine oxide the complex types formed are [215] Ln(NCS)3L3, Ln(N03)3L2 Et0H, Ln(N03)3L3, Ln(NC>3)3L4. Triphenyl arsine oxide complexes appear to be stronger than the phosphine oxide based on the higher dipole moment of arsine. 

DMSO, dimethyl sulphoxide bipy, 2,2,-bipyridyl TPPO, triphenyl phosphine oxide GD, guanidinium DPAE, l,2-di(pyridine-2-aldimino)ethane EPAE, ethylenediaminetetraacetate. 

The stereochemistry of the alkene product in Wittig reactions is thought to be influenced by the reversibility of formation of the isomeric threo and erythro oxaphosphetanes (or betaines) which undergo stereospecific loss of triphenyl-phosphine oxide to give the trans (E) and cis (Z) alkenes, respectively (Scheme 4). Factors that enhance the reversibility of this initial step favour the threo intermediate and hence the (E) alkene. Stabilized phosphoranes give a predominance of the (E) alkene while non-stabilized phosphoranes give the (Z) alkene. In general, stabilized phosphoranes react readily with aldehydes (see Protocol 4) while non-stabilized phosphoranes will react with aldehydes, hemiacetals (see Protocol 5) and ketones.2,3... 

Synthesis of (-I-) calanolide A (Scheme 8-11) was achieved by enzyme catalyzed resolution of the aldol products ( )-53. Compound 7 with acetaldehyde by aldol reaction in the presence of LDA/TiCU stereoselectively produced a mixmre of ( )-53 and ( )-54 (94% yield), the ratio of which was 96 4. ( )-53 was then resolved by lipase AK-catalyzed acylation reaction in the presence of tert-butyl methyl ether and vinyl acetate at 40 °C to obtain 41% yield of (+)-55 and 54% yield of the acetate (—)-56. Mitsunobu cyclization of (+)-55 in the presence of tri-phenylphosphine and dielthyl azodicarboxylate afforded 63% yield of (-l-)-43 with 94% ee as determined by chiral HPLC. Luche reaction on (+)-43 with CeCla 7H2O and triphenyl phosphine oxide and NaBH4 in the presence of ethanol at 30 °C gave the crude product. It was purified by column chromatography on silica gel to give 78% yield of a mixture containing 90% of (+)-calanolide A and 10% (+)-calanohde B, which were further separated by HPLC. 

Fan, H., Liu, Y, Xu, G etal. (1988) Synthesis and structure of diperchlorato-tetrakis (triphenyl phosphine oxide) neodymium mono-perchlorate complex containing one ethanol molecule of salvation. Journal of Inorganic... 

Pyrazolone and its derivative are the most common ligands used for Tb(III) complexes in electroluminescence. In 1998 the first example of an electroluminescent device using a terbium pyrazolonate complex, tris(l-phenyl-3-methyl-4-isobutyl-5-pyrazolone)-bis-(triphenyl phosphine oxide) terbium [Tb(ip-PMP)3(TPPO)2] (Figure 11.20, compound 36),... 

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