14311-22-9Relevant articles and documents
Selective homo- and heterodehydrocouplings of phosphines catalyzed by rhodium phosphido complexes
Han, Li-Biao,Tilley, T. Don
, p. 13698 - 13699 (2007/10/03)
Reactions of the rhodium complex (dippe)Rh(η3-CH2Ph) (1, dippe = iPr2PCH2CH2PiPr2) with ArPH2 (Ar = Ph, Mes) proceed via P-H oxidative additions to the phosphido complexes (dippe)Rh(μ-PHAr)2Rh(dippe) (3a, Ar = Ph; 3b, Ar = Mes). The corresponding reaction of Ph2PH occurs similarly, via the intermediate (dippe)Rh(PPh2)PHPh2 (4), to (dippe)Rh(μ-PPh2)2Rh(dippe) (3c). Complexes 3a-c and 4 are catalysts for the catalytic dehydrodimerizations of the corresponding phosphines to diphosphanes. Complex 1 is a more active dehydrocoupling catalyst, and substituent effects suggest that the active catalyst is mononuclear. Efficient dehydrocouplings of 2-EtC6H4PH2, 2-iPrC6H4PH2, and 2,4,6-iPr3C6H2PH2 were also observed. Complex 1 also catalyzes the heterocoupling of Ph2PH with PhSH (to Ph2P-SPh), and stoichiometric reactions in this system allowed isolation of (dippe)Rh(μ-SPh)2Rh(dippe) (6) and (dippe)Rh(SPh)PHR2 (7a, R2PH = MesPH2; 7b, R2PH = Ph2PH). Copyright
The Kinetics and Mechanism of the Reaction of Tricoordinate Phosphorus Compounds with Diaryl Trisulfides
Hall, C. Dennis,Tweedy, Bruce R.,Kayhanian, Robert,Lloyd, John R.
, p. 775 - 779 (2007/10/02)
Kinetic data and activation parameters are reported for the reaction of a series of tricoordinate phosphorus compounds, , with diaryl trisulfides.The second-order rate coefficients for series of arylphosphines, phosphinites and phosphonites, correlate with the Hammett ? constants of the aryl substituents with ρ values of -1.1, -1.1 and -1.1 respectively and these results are discussed in terms of a biphilic mechanism analogous to that proposed for the reaction of tricoordinate phosphorus with S8.
PHOSPHORORGANISCHE VERBINDUNGEN 90 Methodische Ausgestaltung der P-C und P-S-Cyanolyse am Beispiel einiger Heterophosphoniumsalze
Horner, Leopold,Jordan, Manfred
, p. 215 - 220 (2007/10/02)
Treatment of allylamido-phosphonium salts with dry tetrabutylammonium cyanide in methylenechloride delivers after removal of the allyl group phosphinous acid amides with retention of configuration (P-C-cyanolysis).Allyl-O-alkylphosphonium salts undergo the Arbosov reaction under the above conditions, while allyl-S-alkyl phosphonium salts undergo fission of the P-S bond (P-S cyanolysis).Equally good results were obtained using KCN in methylene chloride accompained by catalytic amounts of 18-crown-6 ether; thus optically active benzyl-methyl-phenyl-phosphine-sulfid gave the corresponding phosphine with retention of configuration.Dithiophosphinic acid esters and thiophosphinic acid amides, after conversion to the corresponding quasiphosphonium salts via S-alkylation and subsequent treatment with tetrabutylammonium cyanide in methylenechloride, also give the corresponding thiophosphinous acid ester and phosphinous acid amide respectively.Thiophosphinic acid O-alkyl esters (R2P(S)OR') give however the thiophosphinic S-alkyl ester (R2P(O)SR') via an Arbusov reaction.The P-C cyanolysis of allyl-triphenylphosphoniumbromide using KCN/18-crown-6 or tetrabutylammonium cyanide in aprotic medium stops at the stage of the intermediary red-coloured ylide; addition of a proton-donor then results in the subsequent rearrangement to the corresponding propenyl-phosphonium salt.
