Dialkylphosphinate complexes

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. 

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,... 

Several heteroatom nucleophiles, for example, amines, alcohols, thiols, carboxylates, and dialkylphosphines, undergo Michael addition reactions with alkene- and alkyne-substituted carbene complexes. Reaction of alkyne-substituted chromium carbenes with urea affords products derived from Michael... 

Zirconium(iv) monobutyl phosphate, Zr(Bu0P03)2, has been prepared and characterized by i.r. spectroscopy. The dialkylphosphinous acid complexes [ R2P(0)H 2ZrX4] (R = Bu,Ph, or cyclohexyl X = Cl or Br) have been prepared from ZrX4 R2P(0)H in benzene and their i.r. spectra reported. "... 

Complexes of diorganophosphinous acids, R2P(0)H, with tin(iv) chloride have been reported. Co-ordination of the dialkylphosphinic and dialkyl-phosphinothioic acids to tin in the complexes [R R P(0)YH]2,SnX4 (Y = O or S) is effected through the phosphoryl oxygen in both cases. The phosphinic acid complexes lose hydrogen chloride at 120—140 °C to form the compounds [R R P(0)0]2SnCl2, which appear to be chain polymers of the type (18.) ... 

The reactivity of palladium complexes can be enhanced by using more electron-rich aryl-dialkylphosphines, or even trialkylphosphines. The most general method for performing the SM reactions, employing Pd2(dba)3 and Pt-Bu3, with aryl iodides. 

Further improvements in the latter class of ligands have been introduced by appropriate immobilization of well established aryl-dialkylphosphines on the suitable polymers. Buchwald and coworkers [140] have developed ligand 326 supported on the Merrifield s peptide resin 343. This forms the highly active palladium complex with Pd(OAc)2 or Pd2(dba)3, wide apphcable in several palladium-catalysed reactions including the SM reactions with unreactive aryl iodides, bromides and chlorides. Thus sterically demanded and deactivated bromo-p-xylene (344) and 2-tolylboronic acid (286) were reacted at 0.5 mol% of paUadium-loading to produce 2,5,2 -trimethyl biphenyl (345) in essentialy quantitative yield [140], respectively. Scheme 45. 

Palladium complexes are able to assist in the Z/ -isomerization and migration of a variety of olefins. Heteroatoms in the olefin and trialkyl- or dialkylphosphines as ligands for palladium support isomerization [134]. 

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