Tri-n-butylphosphine oxide

Compared with the variety of existing carbon or nitrogen nucleophiles that were subjected to nucleophilic addition to there are few examples for phosphorus nucleophiles. Neutral trialkylphosphines turn out to be to less reactive for an effective addihon to Cjq even at elevated temperatures [114], Trialkylphosphine oxides show an increased reactivity. They form stable fullerene-substituted phosphine oxides [115] it is not yet clear if the reaction proceeds via a nucleophilic mechanism or a cycloaddition mechanism. Phosphine oxide addition takes place in refluxing toluene [115], At room temperature the charge-transfer complexes of with phosphine oxides such as tri-n-octylphosphine oxide or tri-n-butylphosphine oxide are verifiable and stable in soluhon [116],... 

To the Co complex (1.28 g, 2.32 mmol) in heptane (23 mL, purged with carbon monoxide for 3 h before use) was added tri-n-butylphosphine oxide (506 mg, 2.32 mmol). The solution was sealed in a screw-cap resealable tub under an atmosphere of CO and heated to 85°C (over glyme heated at reflux) for 71 h. After cooling, the solution was applied directly to a bed of Fluorisil and eluted with ethyl acetate-petroleum ether 95 5 to 50 50) giving the tricyclic enone 304 mg, 45%) as a colorless oil [a]D 22 +116° (c 2.47, CHC13). 

In the mid-1960s liquid—liquid extraction processes were introduced and today all large-scale commercial production is done in this way. An aqueous solution of the Ln3+ ions is extracted in a continuous countercurrent process into a nonpolar organic liquid containing tri-n-butylphosphine oxide or bis(2-ethylhexyl)phosphinic acid (DEHPA). Typical separation factors for adjacent rare earths using DEHPA are 2.5 per extraction step so that under automatic multistep or countercurrent conditions purities of 99 to 99.9% are routinely achieved. 

Dihydrofiirans have seen considerable use as substrates in the Pauson-Khand reaction. The parent compound reacts in excellent yield with acetylene, terminal and internal alkynes. Yields in this system respond very well to the use of catalytic reaction conditions (equation 4). Another unusual experimental modification has also been found by Pauson to be useful in this system addition of tri-n-butylphosphine oxide nearly doubles the product yield in certain cases (equation 37). The role of the added substance is unclear. Addition of phosphine oxide does not always improve reaction efficiency at this time there are no guidelines to indicate when its use might be beneficial. Substituted dihydrofurans give somewhat lower but still acceptable yields the poor regioselectivity in unsymmetrical cases is the more significant difficulty with these substrates (equation 38). 

Epoxide-carbonyl rearrangement.2 Lithium bromide effects facile rearrangement of epoxides to aldehydes and/or ketones in benzene solution. The salt is insoluble in benzene but addition of 1 mole of HMPT or tri-n-butylphosphine oxide per mole of lithium bromide affords a soluble complex which effects the epoxide rearrangement. Evidence suggests a mechanism involving the salt of the bromohydrin as an intermediate. 

Solvation and Shift Reagents.—The solvation parameters for a series of alcohols have been determined using the n.m.r. chemical shift of tris-n-butylphosphine oxide. Ion pair association between tetraphenylboron and cationic centres was used to study the electronic structure of aminonaphthylphosphonium salts (24 X = Ph4B ). Shift reagents have been used in the conformational analysis of adenosine phosphates and aromatic solvent induced shifts to probe the stereochemistry of butadienylphosphonates and their polymers. The geometries of difluorophosphine derivatives were evaluated from liquid crystal n.m.r. studies with the aid of electron diffraction. ... 

Thio ethers. The reagent reacts with primary and secondary alcohols at 20° in the presence of tri- -butylphosphine (triphenylphosphine is not so effective) to form phenyl thioethers, tri-n-butylphosphine oxide, and succinimide. The reaction proceeds with inversion. It is limited to N-(aryIthio)succinimides, since N-(alkyIthio)succinimides are desulfurized by phosphines. 

Hassan and Thoria have developed an amplification procedure for the determination of organo-phosphorus compounds (triphenyl phosphine, tritolylphosphate, diethylbenzyl phosphates, tri-n-butylphosphine oxide, and triphenyl phosphate). The method is based on combustion of the organic compound in an oxygen-filled flask and the formation of the secondary form phosphate by adjustment of the pH value of the combustion product. Calcium iodate is then added and the lOT released is treated with I to obtain an amplification factor of 12. 

TBP, but not necessarily with the same solvation number for all elements. Tri-n-octylphosphine oxide (TOPO) and tri-n-butylphosphine oxide (TBPO) extract Pu(IV) and Pu(VI) as the di-solvate.The data of Martin andOckenden is ven in Figs. 9 and 10 for extraction of several elements into 0.1 M TOPO in cyclohexane from HNOg and... 

Ejxjxi des react with LiBr and tri-n-butylphosphine oxide to form carbonyl systems32 g... 

Phosphorus(V) from phosphorus(lll) compounds. Tribulylphosphine added at 25° under Ng during 30 min. with water-cooling to N,N-diethyl-2,2,2-trichloro-acetamide, and kept an additional 4 hrs. at 50-55° N,N-diethyl-l,2,2-trichloro-vinylamine (startg. m. f. 442) (Y 82.5%) and tri-n-butylphosphine oxide (Y 72.6%).—This new reaction appears to be general for tert. phosphines and trialkyl phosphites. It also represents a novel method for the prepn. of a new class of vinylamines. F. e., also with trialkyl phosphites, which are oxidized to trialkyl phosphates, s. A. J. Speziale and R. G. Freeman, Am. Soc. 82, 903 (1960). 

Fig. 4. Lewis bases that form adducts with rare-earth tris / -diketonates. Abbreviations bipy = 2,2 -bipyridine phen = 1,10-phenanthroline terpy = 2,2, 6, 2"-terpyridyl bath = bathophenanthroline or 4,7-diphenyl-l,10-phe-nanthroline Hpbm = 2-(2-pyridyl)benziraidazole tppo = triphenylphosphine oxide tbpo = tri-n-butylphosphine oxide topo = tri-n-octylphosphine oxide tbp = tributylphosphate dmso = dimethylsulfoxide.

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