Phosphorus tris amide

The other approach to P-ylides based on the nucleophilic addition of phosphorus(HI) reagents to the terminal carbon atom of 1,2-diaza-1,3-butadienes has continued to find application. The reaction with dialkyl-phosphonites or phosphorus(III) amides under solvent-free conditions (and in the presence of atmospheric moisture) was found to be a convenient approach to a-phosphanylidene hydrazones (42). The linear ylides (42) in THF solution undergo further intramolecular transformations to give 1,2,3X -diazaphospholes (43) in the case of phenylphosphinite as a starting substrate or 5-oxo-4-phosphoranyidene-4,5-dihydro-l/f-pyrazoles (44) using tris(dialkylamino)phosphine. 

Stephens, F.H., 2004. Activation of white phosphorus by molybdenum- and uranium tris-amides. 

The alcoholysis and transamination of various aminophosphines have been studied as functions of the basicity of the attacking nucleophile and the substituents on phosphorus. As might be expected the reaction is facilitated by electron-withdrawing groups on phosphorus. The hydrolysis of tris(dimethylamino)phosphine (90) to phosphorous acid has been investigated using thin-layer chromatography and the amides (91) and (92) have been identified as intermediates. 

A method for the preparation of 1,3,2-diazaphospholidine heterocydes has been described by Deng and Chen (Scheme 6.225) [402], The authors found that treating hindered 1,2-diamino substrates such as a-amino acid amides with tris(diethylami-no)phosphine as reagent/solvent under open-vessel microwave conditions at 250 °C for 1 min furnished a trivalent phosphorus intermediate. Subsequent thiation of this intermediate with elemental sulfur in refluxing benzene provided the target l,3,2-diazaphospholidin-4-ones in good overall yields. The yields were much improved compared to those achieved by standard thermal methods. 

Trivalent phosphorus compounds are capable of removing vicinal halogens from organic compounds and thus represent a useful alternative method to dehalogenations with metals. Phosphorus agents employed include triphenylphosphane,112 and phosphorus acid esters (triethyl phosphite154 and tributyl phosphite155) and amides [tris(dimethylamino)phosphane 56 and tris(diethylamino)phosphane 57,158]. 

Tri- and tetrazole aromatase inhibitors Mandelic amide Biaryl compounds Biaryl compounds Polycyclic aromatics Sulfur compounds Phosphorus compounds Nitrogen and cyano compounds... 

Such condensation reactions are also promoted by certain trTvalent phosphorus compounds, e.g. triphenyl phosphite (2) or diphenyl ethylphosphonite (3), or to a lesser extent by pFosphonate esters, e.g. diphenyl n-butylphosphonate (3). "Bates reagent," p-oxobi s[tri s(cTi methyl ami no)phosphoni urn] bi s-tetra-f1uoroborate (2) may also be used to activate the carboxyl function towards amide bond formation during peptide synthesis (4) and to bring about the Beckmann rearrangement of ketoximes (F). 

First, dibromodifluoromethane and hexamethylphosporous amide form a phosphonium salt. The intermediate thus formed reacts with tris(dimethyl-amino)phosphine to give dibromotris(dimethylamino)phosphorane and an ylide with difluoromethylene group attached to phosphorus, difluoro-methylenetris(dimethylamino)phosphorane. 

Tri-ort/io-cresyl phosphate, the contaminant in a homemade liquor called Ginger Jake , which is responsible for delayed neuropathy and paralysis of the legs, is bioactivated to a form that inhibits neuropathy target esterase but not acetylcholinesterase (Casida and Quistad, 2004 Glynn, 2006). Large structures with a 12-20 carbon alkyl chain on the phosphorus atom inhibit fatty acid amide hydrolase but not acetylcholinesterase (Casida and Quistad, 2004). These examples clearly show that OPs which do not affect... 

Schrock discovered that the r-butylalkylidene complex of tantalum (and in lower yield, niobium) was a structural analog to the phosphorus ylide. The complex proved to be a reagent for r-butylalkene formation. Of the Wittig-type reactions tried, most notable was the ability of the complex to react with esters and amides to form the corresponding r-butylalkenes in good yields. 

The third group is water-immiscible organic species with electron donor or acceptor properties, or solvating carriers. They include carbon-oxygen compounds (amides, ethers, ketones) phosphorus-oxygen compounds (tri- -butylphosphate (TBP), dibutyl-phosphate (DBP) or-phosphonate (DBBP) phosphine oxides (tri- -octylphosphine oxide (TOPO) phosphine sulfides (Cyanex 471) alkyl sulfides (dihexyl, diheptyl sulfides) nitrogen containing compounds (CLX 50), and so on [1-7, 81, 83]. All of them are known as selective extractants, but few of them are tested as carriers in LM processes. 

In general, Lawesson s reagent (and, in principle, other dithioxophosphorane dimers) is a powerful agent for simple thiations at both carbonyl and phosphoryl functions, for the preparation of sulphur- and of phosphorus-sulphur-containing heterocyclic compounds (these last being fundamentally derivatives of 4-methoxyphenylphosphono(di, tri)thioic acids and for the coupling of acids and amides, particularly in peptide synthesis. 

Phosphonic mono- and di-amides have been widely examined as substrates in the WEH reaction with the considerable success in the use of their carbanions in the non-stereose-lective synthesis of (j5-hydroxyalkyl)phosphonic diamides the result of decreased elec-trophilicity of the phosphorus atom. The fission of such diamides occurs when they are heated in a high-boiling solvent the separated threo and erythro stereoisomers from, for example, benzylic phosphonic diamides undergo decomposition into ( )- and (Z)-alkenes, respectively, although the exact mechanism is unclear The successful release of alkene from the thiophosphinic amide 175 is possible after methylation to 176 the yields of unsymmetrical disubstituted alkenes are 50 99%, and even for tri- and tetra-substituted alkenes yields of 53-93% are achievable . 

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