Silver trifluoroacetate/iodine

Glacial acetic acid is a suitable solvent for use with silver acetate and CC14 or, up to 150°, nitrobenzene for use with silver trifluoroacetate. The Hunsdiecker reaction (see p. 1005) may intervene as competing reaction 377 trifluoroiodo-methane, for example, may be formed when iodine, silver trifluoroacetate, and nitrobenzene are heated in the absence of a substance that can be iodinated CF3COOAg + I2 ------------------------ CF3I + Agl + C02... 

Iodine silver trifluoroacetate a-Diketones from ketones s. 16, 321... 

Oxidations with iodine/silver trifluoroacetate Aldehydes from prim, alcohols a-Diketones from ketones... 

Free-radical acyloxylation of aromatic substrates has been accomplished with a number of reagents including copper(II) acetate,benzoyl peroxide-iodine, silver(II) complexes, and cobalt(III) trifluoroacetate. ... 

Vicinal iodo carboxylates may also be prepared from the reaction of olefins either with iodine and potassium iodate in acetic acid/ or with N-iodosuccinimide and a carboxylic acid in chloroform. " A number of new procedures for effecting the hydroxylation or acyloxylation of olefins in a manner similar to the Prevost or Woodward-Prevost reactions include the following iodo acetoxylation with iodine and potassium chlorate in acetic acid followed by acetolysis with potassium acetate reaction with iV-bromoacetamide and silver acetate in acetic acid reaction with thallium(III) acetate in acetic acid and reaction with iodine tris(trifluoroacetate) in pentane. ... 

Filimonov et al. reported a synthesis of 3,6-diiodocarbazole (387) by iodination of carbazole (1). For the iodination, the required electrophilic iodine was generated by reacting iodine monochloride (ICl) with silver trifluoroacetate (CFsCOOAg) in acetonitrile. Following this procedure, 3,6-diiodocarbazole (387) was obtained in almost quantitative yield (871) (Scheme 5.270). 

The addition of iodine trifluoroacetate (produced by reaction of iodine with silver trifluoroacetate) to unsaturated carbohydrates has been investigated.134 Treatment of 5,6-dideoxy-l,2-0-isopropylidene-a-D-xylo-hex-5-enofuranose (89) with silver trifluoroacetate and iodine in acetonitrile gave 3,6-anhydro-5-deoxy-5-iodo-l,2-0-iso-propylidene-a-D-gluco(and /3-L-ido)furanose (91) and 5-deoxy-5-iodo-l,2-0-isopropylidene-6-0-(trifluoroacetyl)-o -D-gluco(and/or /3-L-ido)-furanose (92), with the former preponderating. Component 91 was converted into 3,6-anhydro-5-deoxy-l,2-0-isopropylidene-a-D-xj/io-hexofuranose (94) by hydrogenation over Raney nickel (see also, Section III,3 p. 299), and component 92 was converted into 5-deoxy-l,2-0-isopropylidene-a-D-xy/o-hexofuranose (95) by treat-... 

Another strategy for the synthesis of 5-deoxyhexoses involves the anti-Markovnikov hydration of a 5,6-alkene derivative, as first developed by Wolfrom.97,100 Since that report, the same approach has been followed by several authors, and conditions for the key step have been improved. For example, starting from tosylate 43, treatment with sodium iodide resulted in the alkene 44. Addition of iodine trifluoracetate (produced in situ by the reaction of silver trifluoroacetate and iodine) to 44, followed by hydrogenation over... 

A photochemical preparation of a Cephalotaxus alkaloid synthon (20) has been reported (Scheme 2).10 The readily accessible maleimide (17) was iodinated with iodine and silver trifluoroacetate, in 71% yield, and the resulting compound was transformed in two steps (70% overall yield) into the methylene-pyrrolone (18) by the action of methylmagnesium iodide followed by dehydration. Irradiation of (18) afforded (19) (46% yield), which, by successive hydrogenation and reduction with lithium aluminium hydride, gave the dihydro-pyrrolo[2,l-b][3]benzazepine (20). This derivative has served as a key intermediate in the total synthesis of cephalo-taxine described previously (see Vol. 7 of these Reports). 

Potassium permanganate. Dimethyl sulfide-Chlorine. Dimethyl sulfoxide. Dimethyl sulfoxide-Chlorine. Dimethylsulf-oxide Sulfur trioxide. Dipyridine chro-mium(VI) oxide. Iodine. Iodine-Potassium iodide. Iodine tris(trifluoroacetate). Iodosobenzene diacetate. Isoamyl nitrite. Lead tetraacetate. Manganese dioxide. Mercuric acetate. Mercuric oxide. Osmium tetroxide—Potassium chlorate. Ozone. Periodic acid. Pertrifluoroacetic acid. Potassium ferrate. Potassium ferricyanide. Potassium nitrosodisulfonate. Ruthenium tetroxide. Selenium dioxide. Silver carbonate. Silver carbonate-Celite. Silver nitrate. Silver oxide. Silver(II) oxide. Sodium hypochlorite. Sulfur trioxide. Thalli-um(III) nitrate. Thallium sulfate. Thalli-um(III) trifluoroacetate. Triphenyl phosphite ozonide. Triphenylphosphine dibromide. Trityl fluoroborate. 

Silver trifluoroacetate. For use in combination with iodine for the 4-iodination of veratrole," the salt is prepared by adding trifluoroacetic acid to a suspension of precipitated silver oxide in water, filtering, and evaporating the filtrate to dryness. Extraetion of the dry salt with ether in a Soxhiet and evaporation of the solvent gives colorless, crystalline material in 88% yield. 

The preferred procedure for iodination of veratrole employs silver trifluoroacetate. An aqueous solution of the salt is prepared from the acid and silver oxide, filtered, and evaporated to dryness the salt is purified by Soxhlet extraction with ether. A solution of iodine in chloroform is added with stirring under reflux to a mixture of... 

Olefin addition. Addition of iodine and A -cholestene to a solution of silver trifluoroacetate in methylene chloride generates iodine trifluoroacetate which adds to the olefin to give 3a-iodo-2 -trifluoroacetatoxycholestane in 72% yield. Lithium aluminum hydride effects reduction and deacetylation to cholestane-2/3-ol. D. E. Janssen and C. V. Wilson, Org. Syn., Coll. Vol., 4,547 (1963)... 

Trifluoroacetyl hypohalites, CFaCOzX. Prepared by interaction of bromine or iodine with silver trifluoroacetate. ... 

Hydroxylation Lead tetra(trifluoroacetate). Osmium tetroxide. Silver acetate-iodine. Silver chlorate. 

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