Phosphine, tris ethyl

Phosphine, tris[(diphenylphosphino)ethyl]-, 995 Phosphine, tris(2-(diphenylphosphino)phenyl)-, 995 Phosphine, tris(methylamino)-sulfides... 

Tri-tert-butylphosphine Phosphine, tris(1,1-dimethy(ethyl)- (13716-12-6), 75, 81... 

Methylazoxymethyl acetate Tris[l-(2-methyl)aziridinyl]phosphine Tris[l-(2-methyl)aziridinyl]phosphine sulfide Methacrylamidopropyltrimethylammonium chloride Methylaluminium sesquichloride W,W -Methylenebisacrylamide A-(p-Methoxybenzylidene)-p-butylaniline 1 - Methyl-1 -benzyloxy ethyl... 

Tris(2-methylphenyl)phosphine Tris(3-methylphenyl)phosphine Tris(4-methylphenyl)phosphine Tris(2-methyl-2-propenoyl)-2-ethyl-2-hydroxymethyl-1.3-propanediol... 

Apart from tertiary amines, the reaction may be catalyzed by phosphines, e.g. tri- -butylphosphine or by diethylaluminium iodide." When a chiral catalyst, such as quinuclidin-3-ol 8 is used in enantiomerically enriched form, an asymmetric Baylis-Hillman reaction is possible. In the reaction of ethyl vinyl ketone with an aromatic aldehyde in the presence of one enantiomer of a chiral 3-(hydroxybenzyl)-pyrrolizidine as base, the coupling product has been obtained in enantiomeric excess of up to 70%, e.g. 11 from 9 - -10 ... 

The first examples of five-coordinate platinum(II) complexes of the type [Pt(PR3)L]2+ (L = tris(2-(diphenylphosphino)ethyl)phosphine R = Et, OMe, OEt) (104) containing only P-donor atoms have been prepared by the reaction of [PtClL]+ with an appropriate monodentate tertiary phosphine or phosphite ligand.284 Triaryl phosphines and phosphites do not react with the precursor complex, even at elevated temperatures, most probably due to the considerable steric interactions that would occur upon the approach of the P-donor ligand to the platinum(II) center. 

A tandem palladium catalyzed multi-component approach has been devised providing direct access to for instance trisubstituted thiophenes from the simple starting material 3-iodothiophene 41. In a representative experiment, the substrate 41 was converted to the product 42 by treatment with ethyl acrylate and iodobutane in the presence of a catalytic system consisting of Pd(OAc)2, tri(2-furyl)phosphine (TFP), norbomene, and a base. A mechanistic rationale accounting for this outcome was also proposed <06OL3939>. 

The 31P NMR spectra of 28-30 showed signals characteristic of their structural features. Dimeric species 28 with l,l,l-tri(diphenylphosphinomethyl)ethane affords two singlets at 23.0 and —28.6 ppm due to the coordinated and nonco-ordinated P donors, respectively. For trimeric species 29, two singlets occur at 24.3 and 14.4 ppm, ascribed to two classes of P donors in bis[2-(diphenylphos-phino)ethyl]phenylphosphine. Because of two types of P donors in tri[2-(diphenylphosphino)ethyl]phosphine, tetrameric species 30 exhibits two singlets at 16.4 and 24.0 ppm. 

A Michael-type addition reaction of phosphine generated from red phosphorus in concentrated aqueous KOH solution has been noted to provide moderate isolable yields of pure organophosphorus products.27 For example, tris-(2-cyanoethyl)phosphine is produced in 45% isolable yield from acrylonitrile, and tris-(2-[y-pyridyl]ethyl) phosphine oxide is isolated in 40% yield from 4-vinylpyridine under these conditions. Excellent yields of the tertiary phosphine oxide, tris-(2-cyanoethyl)phosphine oxide, have been reported using white phosphorus in absolute ethanol with KOH at ice/salt-bath temperatures.28 A variety of solvent systems were examined for this reaction involving a Michael-type addition to acrylonitrile. Similarly, tris-(Z-styryl)phosphine is produced from phenylacetylene under these conditions in 55% isolated yield. It is noteworthy that this last cited reaction involves stereospecific syn- addition of the phosphine to the alkyne. 

Tolman and co-workers (67) investigated a series of pyrazolyl-derived ligands for this reaction. Initial investigations centered on the use of tris(pyrazolyl) phosphine oxide (95) as a ligand with chirality derived from camphor. Diastereoselectivities with ethyl diazoacetate are poor, slightly favoring the cis isomer, and enantioselectivities are modest, Eq. 50. The BHT esters greatly increase the diastereoselectivity of this process (96 4) at the expense of enantioselectivity (10% ee for trans isomer). 

In a different approach [11] to access pure products, the use of strong oleum (65% SO3) for sulfonation of PPh3 resulted in quantitative formation of TPPTS oxide. This was converted to the ethyl suhbester through the reaction of an intermediate silver sulfonate salt (isolated) with iodoethane. Reduction with SiHCls in toluene/THF afforded tris(3-ethylsulfonatophenyl)phosphine which was finally converted to pure 3 with NaBr in wet acetone. In four steps the overall yield was 40% (for PPhs) which compares fairly with other procedures to obtain pure TPPTS. Since phosphine oxides are readily available from easily formed quaternary phosphonium salts this method potentially allows preparation of a variety of sulfonated phosphines (e.g. (CH3)P(C6H4-3-S03Na)2). 

All presently known phosphamethin-cyanines were prepared according to our original procedure (1964) in which two quaternary salts of a heterocyclic base (e. g. 4) are condensed with tris-hydroxymethyl-phosphine 5 in the presence of a proton-abstracting base The preparation ofbis-[N-ethyl-benzothiazole(2)]-phosphamethin-cyanine-tetrafluoroborate 6 illustrates the synthetic sequence. A mixture of 2 moles of N-ethyl-2-chlorobenzothiazolium-tetrafluoroborate 4 and 1 mole of tris-hydroxymethyl-phosphine 5 in dimethylformamide is slowly reacted with ethyl-di-isopropylamine or pyridine at 0 °C. Addition of water immediately affords the crystalline cyanine dye 6 in ca. 45% yield ... 

A convenient route to trivinylphosphine has been developed by thiol elimination from tris[2-(phenylthio)ethyl]phosphine oxide.56 The reaction mechanism involves a phosphoryl-stabilized carbanion, from which benzene thiolate anion is eliminated. 

Phosphine-catalysed annulation between aldehydes (RCHO) and ethyl allenolate (H2C=C=CHC02Et) gives 6-substituted 2-pyrones (52), proceeding via a zwitterionic (g) enolate.201 The product is derived from the -intermediate, which is favoured by the use of sterically demanding trialkylphosphines, such as tri(cyclopentyl). However, overdoing the phosphine bulk with, for example, the tri(r-butyl) derivative gives no yield. 

Tripodal tritertiary phosphines as 1,1,1-tris(diphenyl--phosphinomethy1)ethane, triphos, and tris(2-diphenylphosphino--ethyl)amine, np3 are capable a) to act as tridentate or tetradentate ligands b) to promote several reactions with formation of several types of metal complexes which are presented. 

Trimethyltin chloride Stannane, chlorotrimethyl- (1066-45-1), 68,116 Trimethylvinyltin Stannane, trimethylvinyl- (754-06-3), 68, 116 Triphenylphosphine Phosphine, triphenyl- (603-35-0), 68,130,138 69, 39 Tripropylaluminum (102-67-0), 66, 186, 188, 193 Tris(diethylamino)sulfonium difluorotrimethylsilicate Sulfur (1+), tris(N-ethyl ethanaminato)-, difluorotrimethylsilicate (1-) (59201-86-4), 69, 48, 49 Tris(tetrabutylammonium) hydrogen pyrophosphate trihydrate ... 

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