Palladium® chloride-silver® acetate

METHYL KETONES 1-Chloro-l-(trimethylsilyl)ethyllithium. Palladium(II) chloride-Silver(I) acetate. Platinum t-butyl peroxide trifluoroacetate. 

Palladium(ll) acetate, 389-392 Palladium(II) acetate-1,2-bis(diphenylphosphino)ethane, 391-392 Palladium acetate-triphenylphosphine, 392 Palladium catalysts, 392-393 Palladium(II) chloride, 393-394 Palladium(II) ehloride-eopper(I) cloride, 346 Palladium(II) chloride-silver(I) acetate, 396-397... 

ALLYLIC ACETOXYLATION Palladium(II) chloride-Silver(I) acetate. 

Abstraction of chloride from a vinylpalladium complex by silver acetate has been reported,45 as well as halide abstraction by silver triflate from arylpalladium halides.46 More interestingly in the context of creating C-C bonds, silver perchlorate was able to promote the reaction of (r -aryl)palladium bromide with dienes. Silver-promoted bromide abstraction led to the formation of (r 1-r 2-enyl)palladium complexes, which evolved further through the regioselective formation of a C-C bond between the aryl group and the former diene. Reactions with nonconjugated dienes suggested that the reaction proceeds via carbometallation of the less crowded double bond. Isomerization and (3 elimination led to a (ri3-allyl)palladium complex (Scheme 10.26).47... 

Another method that has been developed for benzoic acid arylation by aryl iodides involves use of a combination of catalytic palladium acetate with stoichiometric silver acetate in acetic acid (Scheme 14) [61], This method is tolerant of chloride and bromide substitution and most likely proceeds through a Pd(II)-Pd(IV) coupling cycle. Moderately electron-poor to electron-rich benzoic acids are reactive,... 

KETONES 1,3-Benzodithiolylium perchlorate. Benzyl(chloro)bis(triphenyl-phosphine)palladium. Chlorobis-(cyclopentadienyl)hydridozirconium. Iron carbonyl. Manganese(ll) iodide. Silver acetate. Thionyl chloride. Tosylmethyl isocyanide. Tri-p-carbonylhexacarbonyldiiron. 

The conversion of acetylenes into olefinic esters by use of addition reactions has been illustrated by the following two examples, (i) 1-Alkenyl boranes, which are readily prepared by the hydroboration of alkynes, are converted into a,fi-unsaturated carboxylic esters in good yield by reaction with carbon monoxide in the presence of palladium chloride and sodium acetate in methanol the process is carried out at atmospheric pressure and occurs with retention of configuration with respect to the alkenyl borane. (ii) Carboxylic acids add to acetylenes in the presence of silver carbonate to provide a novel synthesis of enol esters, which are formed in an 8 2 mixture of isomers. ... 

Related Reagents. Palladium(II) Chloride-Copper(I) Chloride PaUadium(n) Chloride-Copper(II) Chloride Palladium(II) Chloride-Silver(I) Acetate. 

Silver acetate promoted iodine removal and palladium-catalyzed coupling of aryl iodides and (V-acylated anilides produced ortho-aryl acylated anilides, which were then hydrolyzed to give 2-aryl or 2,6-diarylanilines. This silver-ion assisted palladium-catalyzed aryl-aryl coupling was general (53-96% yields) and showed functional group tolerance for chloride and bromide substituents in either the aryl iodides or anilides (eq 16).i ... 

The reaction is a sensitive one, but is subject to a number of interferences. The solution must be free from large amounts of lead, thallium (I), copper, tin, arsenic, antimony, gold, silver, platinum, and palladium, and from elements in sufficient quantity to colour the solution, e.g. nickel. Metals giving insoluble iodides must be absent, or present in amounts not yielding a precipitate. Substances which liberate iodine from potassium iodide interfere, for example iron(III) the latter should be reduced with sulphurous acid and the excess of gas boiled off, or by a 30 per cent solution of hypophosphorous acid. Chloride ion reduces the intensity of the bismuth colour. Separation of bismuth from copper can be effected by extraction of the bismuth as dithizonate by treatment in ammoniacal potassium cyanide solution with a 0.1 per cent solution of dithizone in chloroform if lead is present, shaking of the chloroform solution of lead and bismuth dithizonates with a buffer solution of pH 3.4 results in the lead alone passing into the aqueous phase. The bismuth complex is soluble in a pentan-l-ol-ethyl acetate mixture, and this fact can be utilised for the determination in the presence of coloured ions, such as nickel, cobalt, chromium, and uranium. 

Another limitation is seen when extra strain is included in the compound to be reduced. Dehalogenation of 3,3-dichlorobicyclo[2.2.0]hexan-2-one with zinc/ammonium chloride in methanol gave, at best, a 25% yield of 3-chlorobicyclo[2.2.0]hexan-2-one (14) together with cyclohexenone and 6-chlorohex-5-enoic acid.128 The best results were achieved with the zinc/ acetic acid system, while addition of water, silver-promoted zinc reduction in methanol, tri-butyltin hydride reduction or hydrogenolysis with palladium in methanol did not result in formation of 14, but various other ring-opened products. 

Palladium/silver-catalyzed Heck reactions have usually involved vinyl or aryl halides and alkenes, but these reaction conditions were also extended to allenes. Indeed, Zenner and Larock65 showed that simple alkyl allenes readily reacted with aryl and vinyl iodide derivatives in the presence of palladium acetate or chloride and silver phosphate. Moreover, the reaction could be rendered asymmetric using chiral ligands the best one was a bisoxazolidine derivative (Scheme 10.37). 

Separation of Pd with a collector. To the sample solution (-100 ml) in 0.1 M HCl, containing not more than 50 pg of Pd and heated to 80°C, add a macerated filter paper and 1 ml of 5% oxalic acid solution. Keep the solution at 80°C for 1 h, then allow it to cool. Filter off the precipitate of elemental gold and silver chloride together with the paper. To the filtrate add successively 2 mg of nickel (as its sulphate solution), 2 ml of 20% potassium sodium tartrate solution [to mask Fe(IIl), Al, Ti, etc.], 2 g of sodium acetate, 1 ml of 0.1 A/ EDTA, and 2 ml of the H2Dm solution (pH -6.5). After 30 min, filter off the precipitate of nickel- and palladium dimethylglyoximates. Wash the precipitate from the filter paper into a beaker, add 1 ml of cone. HCl, and evaporate to 5-10 ml, depending on the quantity of Pd in the solution. 

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