[2966-50-9] · C2AgF3O2 · Silver(I) Trifluoroacetate · (MW 220.89)
(mild Lewis acid with a high affinity for aliphatic halides)
Physical Data: mp 257-269 °C (dec).
Solubility: sol benzene, diethyl ether, water.
Form Supplied in: white solid; widely available.
Analysis of Reagent Purity: contents of Ag can be assayed conveniently by volumetric titration of AgI.
Preparative Method: can be prepared by extraction of an aqueous solution of Silver(I) Nitrate and NaOCOCF3 with ether.1
Handling, Storage, and Precautions: should be protected from light.
Like other silver(I) salts, this reagent has been used for solvolysis of reactive halides. Thus treatment of methoxyallyl bromide with AgOCOCF3 yields the corresponding allyl cation which can be captured as its cycloadduct with furan (eq 1).2
Geminal dibromocyclopropanes, as well as dibromocyclobutanes, are easily hydrolyzed using this reagent.3,4 In the case of substrates containing a side-chain with a nucleophilic hydroxy or carboxylic acid group, products from ring opening of the cyclopropane followed by nucleophilic ring closure (eq 2) have been observed.5
Primary and secondary iodides,6 as well as allylic bromides,7 react with silyl enol ethers in the presence of AgOCOCF3 to give products of alkylation (eq 3). In the case of 2-trimethylsilyloxyfuran, exclusive attack on the 5-position is observed (eq 4).8,9
Thiol esters can be converted into O-esters on treatment with the corresponding alcohol and AgOCOCF3, HgOCOCF3, or copper salts (eq 5).10 Similarly, b-keto thioesters react with amines in the presence of AgOCOCF3 to give b-keto amides (eq 6).11
Propargylic esters rearrange to 1,3-dienyl esters in the presence of a catalytic amount of AgOCOCF3 (eq 7).12,13 For similar transformations, see Silver(I) Tetrafluoroborate.
Newman and Reid found that AgOCOCF3 is an excellent reagent for the oxidation of aromatic dihydrazones into 1,2-diarylacetylenes (eq 8).14
Nycomed Innovation, Malmö, Sweden