Silver tosylate

Heplanai (4). To silver tosylate (11 0 g, 38 mmol) in MeCN (100 mL) were added n-lodoheptane 3(7 0 g, 30 mmoO- The mixture protected from light was maintained 24 h at 20°, poured on ice, the product was extracted with El20 and the residua after removal of the solvenL i ias poured Into NasCOg (20 g) in DMSO (150 mL). After healing 5 mm at 1S0°C under N2, the akfehyda was separated as its 2.4-dimtrophenylhydrazone (DNPH) to afford 6.9 g of 4 DNPH (70%), mp 106-107 0. 

Oxidative homo-coupling of alkyl magnesium reagents possessing /3-hydrogens is achieved in the presence of silver tosylate (AgOTs, 1 mol%) as a catalyst and 1,2-dibromoethane as a reoxidant " . 

When dihalo-bicyclo[n. 1. OJalkanes are solvolyzed, ring-enlargement products are formed. In fact, this reaction is often the method of choice for the preparation of medium-sized rings. As far as the stereochemical outcome of the reaction is concerned, there are conflicting reports in the literature. Thus a mixture of (E)-and (Z)-2-bromocyclononenols has been obtained by solvolysis of 9,9-dibromo-bicyclo[6.1. OJnonane [169] in earlier reports only the (Z)-diastereomer was mentioned [170], and the solvolysis in aqueous acetone in the presence of silver tosylate apparently provides only the ( )-isomer [171]. 

In addition to a-ketoesters, a-iminoesters were successful as substrates, allowing the synthesis of a-amino acid derivatives [equation (7.9)].119 Exposure of 157 to gem-dimethylsilacyclopropane 89 and substoichiometric amounts of silver tosylate produced azasilalactone 158. In contrast to the above-mentioned synthesis of 154, hydrolysis of 158 was not observed on aqueous extraction. The authors attributed the enhanced robustness of 158 to the steric bulk of the anisidine group. 

More recently, this reaction was slightly modified using the more soluble silver tosylate as catalyst (1 mol%) and 1,2-dibromoethane as reoxidant (Scheme 10.2).13... 

One way to increase the nucleofiigacity of halides is to introduce silver ion. Komblum reported that primary unactivated chlorides, bromides and iodides could be oxidized by prior conversion to the tosyl-ate with silver tosylate, followed by reaction in DMSO (Scheme 4). ... 

A modification of the oxidation of alkyl halides to aldehydes is the transformation of the halides into alkyl tosylates on treatment with silver tosylate in acetonitrile at 0-5 °C followed by heating of the crude tosylates with dimethyl sulfoxide and sodium bicarbonate (equation 189) [1000],... 

Ordinarily the reaction of silver tosylate with a secondary or tertiary halide yields only products resulting from elimination. However, if the reaction is carried out at a temperature of —25° or below in a minimum amount of acetonitrile, esters of even tertiary alcohols can be isolated. ... 

Silver oxide, 527, 558, 683, 1011-1015 Silver perchlorate, 1187 N-Silver succinimide, 510 Silver sulfate, 1615 Silva tetrafiuoroborate 1015-1618 Silver p-toluenesulfonate, xe Silver to late Silver tosylate, 303,737,1618 Silva tfifluoroacetate, 495, 504,1618-1019, 1220,1227... 

Aldehydes N,N -Carbonylimidazole. Ethoxymethyleneaniline. Ethyleneimine. For-maldoxime. Imidazole. N-Methyl-N-phenylcarbamyl chloride. p-Nitro-N.N-dimethylaniline. Phosgene. Silver tosylate. Sodium ethoxide. Sodium hypophosphite. Sodium 2-nitropro-panenitronate. Trimethylamine oxide. 

So far I have demonstrated that metal ions play an important role in determining the solid-state structures of polyrotaxanes. Of course, this is not the only important factor. Counter anions also play an important role in determining the solid-state structures. As described above, when silver tosylate is reacted with PR44, ID polyrotaxane 14 is formed. However, when the counter anion is switched to nitrate ion, the same procedure yields a novel 2D polyrotaxane 18. The X-ray crystal... 

Silver tosylate [16836-95-6] M 279.1. The anhydrous salt is obtained by recrystallisation from H2O. Store it in the dark. [Claesson Wallin Chem Ber 12 1851 1879, Beilstein 11 H 97,99.]... 

The peak at 26.2 ml in Figure 1 having UV/ARI 8000 could be due to the complex produced by adding an oxazollne unit at one or both ends of PEG dltosylate. The absorbence of the tosylate ion is lower than that of the ester. [The molar extinction coefficient of ethyl tosylate is 440 and that of silver tosylate is 223 at 254 nm (20).1 However, oxazollnium ions also absorb strongly at 254 nm. 

Hoffmann11 states that silver tosylate can be prepared much more easily ere reaction (1) than (2). 

Silver oxide, 65, 218, 368 Silver (II) oxide, 369 Silver perchlorate, 220, 369-370 Silver tosylate, 370-371 Simmons-Smith reagent, 371-372 Sodium acetamide, 422 Sodium acetylide, 241, 398 Sodium aluminum chloride, 372 Sodium amalgam, 373 Sodium amide, 111, 158, 209, 337, 373-374, 418... 

Preparation. Correction 1, p. 1018, line 5. Read After one-half hour silver tosylate was isolated by filtration and evaporation of solvent, and dried in vacuum at 65°,... 

The Komblum oxidation was the first reported oxidation reaction using DMSO. a-Bromo ketones such as 23 were converted to the corresponding glycoxals in good yield.1 Less reactive halides, such as most benzylic halides and aliphatic halides, can be oxidised by conversion to the tosylate derivative with silver tosylate and then oxidising in situ with a sodium bicarbonate-DMSO mixture.17,18... 

Allylation. Silver tosylate is used in combination with urea, a Lewis base catalyst, to promote allylation of aldehydes with allyltrichlorosilane. 

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