15849-84-0Relevant academic research and scientific papers
Raney-Ni reduction of phosphine sulfides
Demchuk, Oleg M.,?wierczyńska, Wioletta,Dziuba, Kamil,Frynas, S?awomir,Flis, Anna,Pietrusiewicz, K. Micha?
, p. 64 - 68 (2016/12/24)
A variety of tertiary phosphine sulfides have been reduced by Raney-Ni to give the corresponding phosphineswith high efficiency and undermild conditions. Alkyl, aryl, acyclic, cyclic, aswell as sterically crowded phosphine sulfides are reduced with equal facility. Optically active P-stereogenic phosphine sulfides are reduced stereospecifically with clean retention of configuration at P. Reductions of unsaturated phosphinesulfides is not fully chemoselective and takes place with concomitant partial reduction of the double bond. Clean reduction of the unsaturated phosphine sulfides to the corresponding fully saturated phosphines can be achieved in one step by running the reduction under H2atmosphere (balloon).
Development of ruthenium catalysts for the enantioselective synthesis ofP-stereogenic phosphines via nucleophilic phosphido intermediates
Chan, Vincent S.,Chiu, Melanie,Bergman, Robert G.,Toste, F. Dean
supporting information; experimental part, p. 6021 - 6032 (2009/09/24)
This work details the development of ruthenium(ll) catalysts for the enantioselective alkylation of chiral racemic secondary phosphines. The reactions proceed through the intermediacy of nucleophilic phosphido species, which have low barriers to pyramidal inversion; this allows for a dynamic kinetic asymmetric alkylation. The initially discovered [((R)-/Pr-PHOX) 2Ru(H)][BPh 4] (6) catalyst was found to be effective in the reaction with benzylic chlorides; moreover, the alkylation displayed an unusual temperature dependence. However, the limited scope of alkylation of 6 motivated further studies which led to the development of two complementary chiral mixed ligand Ru(ll) catalysts of type [L 1L 2Ru(H)] +. These catalysts were derived from a combination of one chiral and one achiral ligand, where a synergistic interaction of the two ligands creates an effective asymmetric environment around the ruthenium center. The (R)-MeO-BiPHEP/dmpe (dmpe= 1,2-bis(dimethylphosphino)ethane) catalyst (10) was found to be effec tive for the asymmetric alkylation of benzylic chlorides, while the (R)-DIFLUORPHOS/dmpe catalyst (11) was optimal for the nucleophilic substitution of less activated alkyl bromides; the scope of the respective catalysts was also explored.
Highly atom-economic one-pot formation of three different C-P bonds: General synthesis of acyclic tertiary phosphine sulfides
Baccolini, Graziano,Boga, Carla,Mazzacurati, Marzia
, p. 4774 - 4777 (2007/10/03)
The reaction of benzothiadiphosphole 1 with an equimolar mixture of R 1MgBr and R2MgBr gave intermediate A′, which, after only 4-5 min, was treated with an equimolar amount of R3MgBr, giving the asymmetric phosphine PR1R2R3 in 45% overall yield (75-80% yield when R1 = R2 and 85-90% yield when R1 = R2 = R3) and the byproduct 6 in 90% yield. The treatment of 6 with PCl3 quantitatively regenerates the starting reagent 1. Treatment of the phosphines with elemental sulfur gave the corresponding sulfides.
Preparation of Alkylmethylphenylphosphines by the Method of Hewertson and Watson
Wolfsberger, Werner
, p. 295 - 298 (2007/10/02)
The reaction of C6H5(CH3)PNa with some alkyl halides in liquid ammonia was studied.The resulting phosphines were characterized by elemental analyses, NMR spectra, and by the reaction with trimethylsilyl azide giving trimethylsilylimino triorganophosphoranes. - Keywords: Alkylmethylphenylphosphines, N-Trimethylsilylimino Triorganophosphoranes, NMR Spectra
A Simple Synthesis and Some Synthetic Applications of Substituted Phosphide and Phosphinite Anions
Tsvetkov, E. N.,Bondarenko, N. A.,Malakhova, I. G.,Kabachnik, M. I.
, p. 198 - 208 (2007/10/02)
Based on data for the acidity relationship of phosphines and phosphinous acids and water in dimethyl sulfoxide and water, a simple method is reported for the generation of phosphide and phosphinite anions by the action of concentrated aqueous alkali on primary and secondary phosphines as well as phosphinous acids in dimethyl sulfoxide or other dipolar aprotic solvents.Alkylation of the anion yields secondary and tertiary phosphines, polyphosphines, functionally substituted phosphines as well as similarly substituted phosphine oxides.Phosphinous acids have beenalkylated in various solvents in two-phase systems containing concentrated aqueous alkali and tetrabutylammonium iodide as phase transfer catalyst.
Stereospecific Synthesis of Diastereoisomerically Pure (-)-(RP)-O-Mentyl Methylphenylphosphinite and Ethylphenylphosphinite: Key Intermediates in Synthesis of Chiral Tertiary Phosphines
Omelanczuk, Jan,Perlikowska, Wieslawa,Mikolajczyk, Marian
, p. 24 - 25 (2007/10/02)
The reaction of the diastereoisomerically pure (-)-(RP)-O-mentyl methylphenylphosphinite (9) and (-)-(RP)-O-mentyl ethylphenylphosphinite (2) with organolithium reagents has been found to give chiral tertiary phosphines (10) and (11) with a very high optical purity.
PHOSPHORORGANISCHE VERBINDUNGEN 92 Zur Stereochemie und zum chemischen Verhalten optisch aktiver Amidophosphoniumsalze und optisch aktiver Phosphinigsaereamide
Horner, Leopold,Jordan, Manfred
, p. 225 - 234 (2007/10/02)
Optically active amides of phosphinous acids R1R2PNR2 4 (R1 = Ph, R2 = Me, R = Et) may be obtained in high yield from the corresponding chiral amidophosphonium salts 1R2R3PNR2>X(R1 = Ph, R2 = CH3, Et, R3 = Bz or allyl, R = Et) via cathodic fassion or cyanolysis, both processes proceeding under retention of configuration at phosphorus.The optically active amidophosphonium salts (e.g. ethyl-methyl-phenyl-diethylamidophosphonium iodide 10 or benzyl-ethyl-phenyl-diethylamidophosphonium bromide 12 were prepared: a.) from the optically active tertiary phosphines (e.g.R-(+)-benzyl-methyl-phenyl-phosphine 6 or S-(-)-ethyl-methyl-phenyl-phosphine 13 on treatment with aryl or alkyl azides and subsequent alkylation of the ensueing phosphine imine 7. b.) from the chiral phosphinous acid amide 4 on alkylation.Methods a) and b) proceed under retention of configuration at phosphorus. c.) treatment of chiral phosphines with N-haloamines results in racemic amidophosphonium salts. Optically active amidophosphonium salts (eg.S-(+)-benzyl-methyl-phenyl-diethylamidophosphonium bromide 8 or R-(-) 10) are converted to the corresponding phosphine oxides 9 or 11 under inversion of configuration on treatment with aqueous alkali.LiAlH4 removes the amino ligand, converting amidophosphonium salts (eg.S-(+) 12) to the optically active phosphine under retention of configuration.Treatment of S(+)-ethyl-phenyl-diethylamidophosphonium bromide 5 with benzaldehyde gives stilbene and chiral ethyl-phenyl-phosphinic acid diethylamide 17 under retention of configuration; 7 is also obtained from R-(-) 4 on oxidation with H2O2.R-(-) 4 gives optically active ethyl-phenyl-thiophosphine acid diethylamide 18 on treatment with sulphur.Optically active 4 undergoes spontaneous racemization at 130 deg either in the neat phase or dissolved in hydrocarbons, zero order kinetics being observed.The racemization is proposed to occur through a cyclic bimolecular association, since compounds with different groups at phosphorus and nitrogen exchange ligands (forming crossed the phosphinous acid amides in approximately equal quantities) after three hours at 200 deg C.Phosphinous acid amides (eg. 4) form chiral charge-transfer complexes with nitrobenzene, which undergo racemization quickly even at room temperature.Optically active 4. when used as co-catalyst with (RhCl-hexa-1,5-diene), enables the homogeneous hydrogenation of α-ethylstyrene to 2-phenylbutane to be carried out with an optical yield of 34percent.
Preparation and (31)P nuclear magnetic resonance studies of chiral phosphines
Payne, Nicholas C.,Stephan, Douglas W.
, p. 15 - 21 (2007/10/02)
The reaction of Li metal with alkyldiphenylphosphines generates the alkylphenylphosphide anions, which can undergo subsequent reactions with alkyl halides to give chiral phosphines (RR'R''P).The (31)P nmr chemical shifts have been measured for these phosphines, and show greater deviations from the values predicted by the first order additivity model than do those of more symmetrical phosphines (i.e., R3P and R2R'P).The shifts for these chiral molecules, and for a wide range of other phosphines, can be accurately predicted using a second order pairwise additivity scheme.The dependence of the observed and calculated chemical shifts upon electronegativity and steric factors is discussed.
Phosphinegold (I) salts having antiarthritic activity
-
, (2008/06/13)
The compounds are (pyridine) (trisubstituted phosphine) gold(I) salts which have antiarthritic activity.
