Samarium iodine

Samarium iodide selectively cleaves trifluoracetylated hydrazines. Since direct cleavage of the N-N bond in 30 did not work with samarium iodine, it was necessary to trifluoracetylate the carbamate first. 

Ethyl sulfate Flammable liquids Fluorine Formamide Freon 113 Glycerol Oxidizing materials, water Ammonium nitrate, chromic acid, the halogens, hydrogen peroxide, nitric acid Isolate from everything only lead and nickel resist prolonged attack Iodine, pyridine, sulfur trioxide Aluminum, barium, lithium, samarium, NaK alloy, titanium Acetic anhydride, hypochlorites, chromium(VI) oxide, perchlorates, alkali peroxides, sodium hydride... 

The radionuclides commercially available and most commonly used for a number of the foregoing applications include anhmony-125 banum-133, 207 bismuth-207 bromine-82 cadmium-109, 115 m calcium-45 carbon-14 cerium-141 cesium-134, 137 chlorine-36 chromium-51 cobalt-57, 58, 60 copper-64 gadolimum-153 germanium-68 gold-195. 198 hydrogen-3 (tritium) indium-111, 114 m iodine-125, 129, 131 iron-55, 59 krypton-85 manganese-54 mercury-203 molvbdenum-99 nickel-63 phosphorus-32. 33 potassium-42 promethium-147 rubidium-86 ruthenium-103 samarium-151 scandium-46 selenium-75 silver-110 m sodium-22, strontium-85 sulfur-35 technetium-99 thallium-204 thulium-171 tin-113, 119 m, 121 m. titamum-44 ytterbium-169, and zinc-65. 

Both tram- and c7r-[l,2,5]trithiepan-4,6-dicarboxylates 402 and 403 were obtained by the reductive ring opening and rearrangement of l,2,3-thiadiazole-4-carboxylates 401 upon reaction with samarium and iodine (Scheme 84). The expected thiadiazoline 404 was not obtained in this reaction <20040BC2870>. 

Representative procedure - preparation of Smf using Imamoto s procedure. Samarium powder (1.00 g, 6.65 mmol) was placed in a reaction flask under an inert atmosphere and thoroughly degassed THF (55 ml) was added. Iodine (1.41 g,... 

In recent years, exposing the preparation of the reagent from samarium metal and an oxidant to different stimuli has led to significant improvements in reaction time. Concellon utilized the sonication of samarium metal and iodoform at room temperature to give a solution of Sml2 in THF in approximately 5 min (Scheme 2.3).5 This approach was also used by Flowers to synthesise other Sm(II) species.6 It was also reported that using different oxidants, such as 1,2-diiodoethane, diiodomethane and iodine, works just as well with this technique.5... 

Hilmersson7 achieved similar results by heating the reaction to 180 °C under microwave conditions for 5 min (Scheme 2.3). Although this method is compatible with all of the oxidants described above, formation of Sml2 from samarium metal and iodine is preferred as no gas evolution accompanies the reaction.7... 

There exists also a synthesis of cyclopentadecanone (VII/81) and ( )-mus-cone, based on a three-carbon annulation of cyclic ketones followed by the regioselective radical cleavage of the zero bridge of the so formed bicyclic system [44], The synthesis of cyclopentadecanone is summarized in Scheme VII/16. The cyclization of VII/78 to the bicyclic alcohol VII/79 proceeds best (94 % yield) with samarium diiodide in the presence of hexamethylphosphoric acid triamide and tetrahydrofuran [45], The oxidative cleavage of VII/79 to the ring expanded product VII/80, was performed by treatment with mercury(II)-oxide and iodine in benzene, followed by irradiation with a 100 Watt high pressure mercury arc. Tributyltinhydride made the de-iodination possible. 

The exploration of Lnl2(THF) c, in particular, Sml2(THF)4, which is prepared by the reaction of samarium metal with ICH2CH2I in THF [96], or the reaction of iodine with an excess of samarium metal in THF, provides appropriate starting materials for divalent organometallic complexes (Equation 8.29). 

Samarium diiodide is very conveniently prepared by oxidation of samarium metal with organic di-halides or with iodine (equations 10-12). Deep blue solutions of SmI (0.1 M in THF) are generated in virtually quantitative yields by these processes. This salt can be stored as a solution in THF for long periods when it is kept over a small amount of samarium metal. Tetrahydrofuran solutions of SmI are commercially available as well. If desired, the solvent may be removed to provide Sml2-(THF)n as a powder. For synthetic purposes, Smh is typically generated and utilized in situ. 

A slightly different approach has been utilized for the three-carbon expansion in a system which does not contain a carboalkoxy group. The initial intramolecular addition step is carried out separately with butyllithium or samarium diiodide to give a bicyclic alcohol (Scheme 78). The radical-induced fiag-mentation step is carried out photochemically in the presence of mercury(II) oxide and iodine to provide the expanded iodo ketone. 

FP-2 (iodine, cesium, rubidium, strontium, barium, europium, samarium)—are removed during the reduction step by extraction into the salt phase. There will be an accumulation of FP-2 fission products in the salt which is controlled by a continuous salt bleed. For 1000 kg of fuel, 2000 kg of salt are required. 

Reaction of SmCl3(THF)3 with lithium and 1,4-diphenyl-1,3-butadiene led to [Li(THF)4][Sm(l,4-Ph2C4H4)2]. One more samarium complex (l,4- p-MeC6H4 2C4H4)SmI(THF)3 was obtained by reaction of metallic samarium with l,4- />-MeC6H4 2C4H4 in the presence of iodine (Scheme 26).168... 

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