Dialkylphosphinates

Flotation Reagents. Only one sulfide mineral flotation collector is manufactured from phosphine, ie, the sodium salt of bis(2-methylpropyl)phosphinodithioic acid [13360-78-6]. It is available commercially from Cytec Industries Inc. as a 50% aqueous solution and is sold as AEROPHINE 3418A promoter. The compound is synthesized by reaction of 2-methyl-1-propene [115-11-7] with phosphine to form an iatermediate dialkylphosphine which is subsequently treated with elemental sulfur [7704-34-9] and sodium hydroxide [1310-73-2] to form the final product (14). The reactions described ia equations 10 and 11... 

Dialkylphosphinous acids react with perfiuoroalkenes under free radical conditions to form carbon-phosphorus bonds [10] (equation 7)... 

When a surplus of aldehyde or ketone is used, a considerable proportion of dialkylphosphine is formed, as shown in Eq. (100) ... 

Bulky dialkylphosphines (HPR2, where R /-butyl, cyclohexyl, 1-adamantyl, 2-norbornyl, and the like) were used together with simple CO- and CN-palladacycles for cross-coupling of unactivated chloroarenes with arylboronic ligands (Pd L=1.5, K3PO4, dioxane, reflux),413 thus apparently having a similar activity as trialkylphopshines. 

Danesi, P. R. Reichley-Yinger, L. Mason, G. Kaplan, L. Horwitz, E. P. Diamond, H. Selectivity structure trends in the extraction of cobalt(II) and nickel(II) by dialkyl phosphoric, alkyl alkylphosphonic, and dialkylphosphinic acids. Solvent Extr. Ion Exch. 1985, 3, 435 152. 

Reasonable yields (55-85%) of dialkylphosphinic acids have been reported from a complex reaction system beginning with red phosphorus, iodoalkane, and elemental iodine.26 Presumably, the phosphorus trihalide is generated as an intermediate. The reaction is worked up with a nitrous acid system from aqueous HCl/NaN02. 

Kudryavtseva, L.I., Alkylation of phosphorus iodides. V. Preparative method for dialkylphosphinic acids, Zh. Obshch. Khim., 60, 833, 1990. 

Razumov, A.I, Mukhacheva, O.A., and Sim-Do-Kem, Some esters of alkaneth-iophosphonic, alkeneselenophosphonic, dialkylphosphinic, and alkane-phosphonous acids and the mechanism of the addition reactions of these esters, Izv. Akad. Nauk S.S.S.R., 894, 1952. 

A group at IGEN raised antibodies to the dialkylphosphinic acid [107]. These were screened for their ability to hydrolyse four alkyl esters and four primary amides at pH 5.0,7.0, and 9.0. Just one out of 68 antibodies, 13D11, hydrolysed the C-terminal carboxamide stereospecifically of only the (/ )-substrate [108], which was rendered visible by the attachment of a dansyl... 

The molecular ion appears to retain its cyclic structure, but several ions with two or three phosphorus atoms can be detected.192 The fragmentation patterns of a number of dialkylphosphines (157) show initial loss of an alkyl group as a neutral particle formed by the transposition of hydrogen.193 Some six-membered cyclic phosphites (158 X = OEt, OPh, or Cl) have been studied.194 The mass spectra of a wide variety of phosphine sulphides (159 Z = Ph, Me, CH2Ph, COPh, NH2, N=CHPh, or... 

Like the divalent metal phosphinates they are often insoluble. However, soluble polymers have been obtained with long chain dialkylphosphinic acid such as A1(02P(C8Hi7)2)3 and the copolymers Al(02PCH2C6H5,C4H9) (02P(C8Hi7)2)2 and Cr(02PMePh)2(02P(C4H9)2 [87]. 

Dialkylphosphine oxides are another class of highly efficient ligands for coupling reactions using Pd or Ni (equation 85). Electron-poor fluoroazines and -diazines react already in the presence of NiClafdppp) , while hindered and electron-rich P(Bu-t)3 and (t-Bu)2P(S)H can be used for the coupling of unactivated aryl chlorides in the presence of Ni. 

A convenient procedure for preparing dialkylphosphinic acids 62 involves addition of H-phosphinic acids and esters to conjugated double bonds via the silyl 87-89 or metal phos-phonite 61,[90 94] as illustrated in Scheme 21. The silyl phosphonite intermediates 61 (M = TMS) are typically formed either from phosphinic acids or esters using chlorotri-methylsilane or bis(trimethylsilyl)acetamide. The metal phosphonite intermediates 61 (Y = Li, Na, etc.) are prepared by deprotonation of the acids with a base such as sodium hydride, sodium methoxide, or lithium diisopropylamide. The conjugated double bonds are typically acrylic acids and esters substituted in the a-position with the appropriate amino acid side chain. After appropriate protecting group manipulations, additional amino acids... 

Zhu, Y., Song, C., Jiao, R. 1995. Partitioning studies in China and the separation of americium and fission product rare earths with dialkylphosphinic acid and its thio-sub-stituted derivatives. Global 1995 International Conference on Evaluation of Emerging Nuclear Fuel Cycle Systems, September, Versailles, France. 

The addition of 0.01 mol L 1 dialkylphosphinic acids and alkylphosphonic acids in a nonirradiated 30% TRPO-kerosene system had no effect on the extraction of Pu(IV) with TRPO. Thus, these acids were not complexing materials for plutonium. The polymeric species were responsible for plutonium retention and emulsification in contact with NaOH or deionized water. The effective elimination of these compounds was obtained by vacuum distillation of the irradiated TRPO-kerosene (67,167). 

Dialkyl-ligated tropocoronand complexes, with Hf(IV), 4, 811 Dialkylphosphine oxides, and Grignard reagent reactivity,... 

An air-stable ferrocenyl-dialkylphosphine is an effective catalyst for the Baylis-Hillman reaction chiral analogues have also been developed to render it enantioselec-tive.171... 

Synthesis of (Silylamino)phosphines. In a typical preparation, addition of one molar equivalent of PCI3 to a stirred solution of LiN(SiMe3)2 in ether at -78°C followed by one or two equivalents of an alkyl Grignard or lithium reagent at 0°C gives the corresponding mono- or dialkylphosphine. This proce-... 

Oxidative Phosphinylation A New Route to Dialkylphosphinic Acid Derivatives... 

The most reactive in this reaction were N-phosphorylated salts of isoquinoline, which hetarylated indole even at room temperature. Pyridine and particularly quinoline are less reactive. With these heterocycles the reaction took place only in the presence of the more active dialkylphosphinic acid chlorides. The steric effects of the substituents at the phosphorus atom have a definite role. It was found that substituents with smaller molecular mass and less branched substituents made it possible to conduct the reaction under milder conditions and lead to an... 

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