Silver- or mercury salt

Potassium nitroacetate 53a reacts with Me3SiCl in aprotic solvents to give SENA (51a) in moderate yield. At the same time, the introduction of yet another electron-withdrawing group (N02 or CC>2Me) stabilizes the anion of salt (53) to an extent that it does not react with Me SiCl by the Sm mechanism without electrophilic assistance. Hence, K or Na salts 53b, C are inert with respect to halosilanes, and silver or mercury salts are required for the preparation of the corresponding nitronates. The latter salts are much safer to use as diox-anate complexes. These complexes react with halosilanes in inert aprotic solvents... 

Fluoxuridine Fluoxuridine, 5-fluoro-l-(2-deoxyribofuranosyl)-pyrimidin-2,4-(l//,3//)-dione (30.1.3.5), is a pyrimidine nucleotide made by reacting fluorouracil (30.1.3.3) with 2-deoxyribofuranosylbromide in the presence of silver or mercury salts [29-33]. 

O-Glycosylation. Traditional glycosylation catalysts are silver or mercury salts. Recently silver zeolite2 has been recommended as the catalyst for preparation of 1,2-cw-glycosides. The thallium zeolite is useful when the glycosyl bromide is unstable in the presence of silver catalysts.1 Example ... 

Allenic alcohols with a variety of allene substitution patterns form 2-alkenyltetrahydropyrans by a 6-exo ring closure upon cyclization with silver or mercury salts (equation 91 ).209 The organosilver intermediate undergoes protiodemetallation under the reaction conditions, while the vinylmercury... 

The A-chloro compound 176, obtained from the corresponding meth-oxyamide with f-butyl hypochlorite, was cyclized to l-methoxy-2-indolone 163 by silver carbonate in trifluoroacetic acid (87% yield) (84JA5728), or by other silver or mercury salts (87T2577), and more conveniently by anhydrous zinc acetate in 1,2-dichloroethane (91% yield) (87CL1771). The reaction proceeds through the spiro intermediate 177, followed by both possible 1,2-shifts. 

In a similar way, 6-evo-iodo or bromo-2-azabicyclo [2.2.0]hexanes rearranged into 5,6-difunctionalized 2-azabicyclo[2.1.1]hexanes on treatment with silver or mercury salts. An aziridinium intermediate was probably formed in the presence of silver ions. Opening of this aziridinium then occurred in a stereocontrolled manner by addition of the silver counterion (Scheme 3.10).21... 

A methylthiomethyl (MTM) group is removed by acid or can be cleaved by mild treatment with aqueous silver or mercury salts (neutral mercuric chloride) to which most other ethers are stable as a result, the selective deprotection of polyfunctional molecules becomes possible using MTM ethers for the hydroxy groups. 

Decarboxylation of an aliphatic acid to the hydrocarbon is best effected by the so-called salt degradation method. That method is to treat the silver or mercury salt of, preferably, an aliphatic or alicyclic carboxylic acid with bromine in an inert solvent a halogenated hydrocarbon is then formed, together with carbon dioxide and the metal bromide, usually in an exothermic reaction, and the bromine can then usually be readily removed either cata-lytically or by means of a Grignard reagent (the Hunsdiecker reaction) ... 

Thallittm z oIile , 4A and 13X, The catalyst is prepared from a mixture of TliCOj and the crushed molecular sieves in water at 45, and then washed with acetone and dried at 190. Co or Cd zeolites arc prepared similarly with CoCO or CdCO). 0 Glyto lation. 1 raditional glycosylation catalysts ate silver or mercury salts. Recently silver zeolite has been recommended as the catalyst for preparation of 1.2-ciS glyooside. The thallium zeolite is useful when the glycosyl hromide is unstable in the presence of silver catalysts. ... 

Nitrobenzene reacts explosively with nitric acid. Reaction with nitrogen tetrox-ide produces explosive products. Violent reactions may occur when combined with finely divided metals. Many metal perchlorates, such as silver or mercury salt, form shock-sensitive adducts with nitrobenzene. 

Pyridinethiol esters are readily reduced with Sodium Boro-hydride in the presence of isopropanol. Activation of 2-pyridinethiol esters with lodomethane allows for mild trapping with alcohols or benzenethiol, yielding esters or thiolesters. In these cases the use of iodomethane avoids the need for thiophilic silver or mercury salts and allows for transthiolesterification. 

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