Platinum complexes, preparation

It is worth mentioning that, in a related study, a chiral platinum complex prepared from bis(cyclooctadiene) platinum [Pt(COD)2] (5 mol %) and (f ,f )-Me-DuPhos (6mol%), also catalyzed the reaction of 63 c efficiently to provide the product (R)-65c... 

Sucralfate [54182-58-0] an aluminum salt of sucrose octasulfate, is used as an antacid and antiulcer medication (59). Bis- and tris-platinum complexes of sucrose show promise as antitumor agents (60). Sucrose monoesters are used in some pharmaceutical preparations (21). A sucrose polyester is under evaluation as a contrast agent for magnetic resonance imaging (mri) (61). Oral adrninistration of this substance opacifies the gastrointestinal tract and eliminates the need for purging prior to mri. 

Salts of neodecanoic acid have been used in the preparation of supported catalysts, such as silver neodecanoate for the preparation of ethylene oxide catalysts (119), and the nickel soap in the preparation of a hydrogenation catalyst (120). Metal neodecanoates, such as magnesium, lead, calcium, and zinc, are used to improve the adherence of plasticized poly(vinyl butyral) sheet to safety glass in car windshields (121). Platinum complexes using neodecanoic acid have been studied for antitumor activity (122). Neodecanoic acid and its esters are used in cosmetics as emoUients, emulsifiers, and solubilizers (77,123,124). Zinc or copper salts of neoacids are used as preservatives for wood (125). 

A derivative of cyclopentyne has been trapped in a matrix. Although cycloheptyne and cyclohexyne have not been isolated at room temperatures, Pt(0) complexes of these compounds have been prepared and are stable." The smallest cyclic allene" so far isolated is l-/err-butyl-l,2-cyclooctadiene 107." The parent 1,2-cyclooctadiene has not been isolated. It has been shown to exist transiently, but rapidly dimerizes." " The presence of the rert-butyl group apparently prevents this. The transient existence of 1,2-cycloheptadiene has also been shown," and both 1,2-cyclooctadiene and 1,2-cycloheptadiene have been isolated in platinum complexes." 1,2-Cyclohexadiene has been trapped at low temperatures, and its structure has been proved by spectral smdies." Cyclic allenes in general are less strained than their acetylenic isomers." The cyclic cumulene 1,2,3-cyclononatriene has also been synthesized and is reasonably stable in solution at room temperature in the absence of air." ... 

The generalized application of the aminolysis of halophosphanes has been the method of choice for the preparation of a wide variety of chiral phosphinous amides by starting from enantioenriched primary amines [36]. The aminolysis reaction occurs efficiently even when the halophosphane is placed in the coordination sphere of a metal, as in the palladium and platinum complexes of the type ds-M(Ph2PCl2)2Cl (M=Pd, Pt) [37,38]. 

Peng YL, Lai SL, Lin CC (2008) Preparation of polypeptide via living polymerization of Z-Lys-NCA initiated by platinum complexes. Macromolecules 41 3455-3459... 

C20-0115. In the 1890s, Alfred Werner prepared several platinum complexes that contained both ammonia and... 

When tetranuclear platinum complex (35) bridged by tetra(4-ethynylphenyl)-methane was used as the core (Fig. 6), dendrimers having more platinum atoms than those prepared from trinuclear platinum core 30 in the molecule were obtained up to the third generation. GPC analysis of these dendrimers revealed that the dendrimers with a tetraplatinum core have a similar molecular size to those with the triplatinum core 30. 

Several hydrido(phenoxo) complexes of nickel, trans-[NiH(OPh)L2] (6) (a L= P Prs b L = PCys c L = PBnj), have been prepared by the metathesis reaction of NaOPh with trans-[NiHClL2] (Eq. 6.6). The complex 6c was obtained as the phenol-solvated complex whose structure was determined by X-ray analysis [9]. An analogous platinum complex trans-[PtH(OPh)(PEt3)2] (7) was prepared by the reaction of trans-[PtH(N03)(PEt3)2] with NaOPh (Eq. 6.7). The complex 7 is air-stable but thermally sensitive and decomposes at room temperature. The structure was elucidated by X-ray analysis [10]. 

The stereoselective catalyzed addition of water or methanol to dimethyl acetylenedicarboxylate (DMAD) was reported to yield oxalacetic acid dimethylester or dimethyl methoxyfumarate. The catalyst precursor cis-[Pd(PMe2Ph)2(solvent)2] [BFJj was prepared from ds-[PdCl2(PMe2Ph)2] and AgBp4 (Eq. 6.54). The analogous platinum complex was not effective, however [99]. 

Hydrogen bonding between an SiOH group and fluorine occurs in the platinum complex 44 [prepared by hydrolysis of a bis(alkylidene)-silacyclopropane] in which the SbF6 anion hydrogen bonds to the platinum-containing cation (O - F distance 2.77(2) A) (249). The platinum complex 45 is not reported (250) to form hydrogen bonds, and a more recent study (210) has confirmed that there do not appear to be any OH OH or OH tt interactions. 

Platinum(IV) complexes have been known to be anticancer active since the original studies in this area by Rosenberg.447 Consequently numerous platinum(IV) complexes have been prepared for biological testing. Until recently, the great bulk of these were trans-dihydroxo complexes prepared... 

The cA-PtCl2(diphosphine)/SnCl2 constitutes the system mostly used in catalyzed hydroformylation of alkenes and many diphosphines have been tested. In the 1980s, Stille and co-workers reported on the preparation of platinum complexes with chiral diphosphines related to BPPM (82) and (83) and their activity in asymmetric hydroformylation of a variety of prochiral alkenes.312-314 Although the branched/normal ratios were low (0.5), ees in the range 70-80% were achieved in the hydroformylation of styrene and related substrates. When the hydroformylation of styrene, 2-ethenyl-6-methoxynaphthalene, and vinyl acetate with [(-)-BPPM]PtCl2-SnCl2 were carried out in the presence of triethyl orthoformate, enantiomerically pure acetals were obtained. 

Isomerization involving a square planar complex is also known. Because of the trans effect, it is easier to synthesize the trans isomer of many complexes than it is to prepare the cis complex. The following reactions lead to the formation of an unusual platinum complex ... 

D. Cole-Hamilton, Liverpool University Professor Gray, some of the platinum complexes that you have prepared at the same time as producing hydrogen contain, formally at least, Pt(III). Can these compounds act as oxidising agents, either thermally or photochemically ... 

Stone and co-workers (16) recently announced that they had isolated and characterized a novel class of crystalline platinum(II) complexes prepared at room temperature by oxidative addition of hydrogen or of R3SiH (R3 = Me2Et, Me2CH2Ph, Cl3, or Et3)to (cyclo-C6H1, P Pt (C2H4. All these complexes were found to be excellent catalysts for hydrosilation... 

In relation to the mechanistic proposal, an interesting reactivity of (boryl)(silyl)platinum(n) complex has been reported.223 The complex is prepared by the reaction of silylborane with Pt(cod)2 complex via oxidative addition (Scheme 46). The (boryl)(silyl)platinum complex undergoes insertion of alkynes at the B-Pt bond to give (/3-borylalkenyl)(silyl)platinum(n) complex in high yield. Importantly, the insertion takes place regioselectively, with Pt-G bond formation at the internal. -carbon atom. This result may indicate that the boron-transition metal bond is more prone to undergo insertion of unsaturated molecules. 

Platinum catalysts, 70 100 Platinum complexes, in silicone network preparation, 22 563... 

Much of the chemistry of palladium and platinum sulfoxide complexes has been discussed in previous sections and so only additional salient points will be mentioned here. A complete listing of all palladium and platinum sulfoxide complexes prepared would require a review article in itself. 

In contrast to the usual yellow, orange, red, or colorless platinum complexes, platinum-blues are unusual for their intense blue or purple colors. The first blue platinum compound was prepared by German chemists at the beginning of this century (19). This unusual material was prepared by the reaction of Ag2S04 with yellow cis-... 

Kneen has also used the ligand ortho-2-methallylphenyl-diphenyl-phosphine, mp, to prepare the chelate complexes PtBr2 (mp) and PdCl2 (mp). The platinum complex reacted with bromine to give a red oil which was not investigated further. 

Attempts to prepare platinum complexes in which the ligands behave as tridentate donors, (Fig. 37) by treating the complexes PtBraL with... 

Platinum tetrachloride is used to prepare chloroplatinic acid and many platinum complexes, particularly with ammonia. Such complexes were pre-... 

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