1,2-Oxatellurolium chloride

High yields of 1,2-oxatellurolium chlorides 67 were achieved in the thermal- or AlCl3-catalyzed rearrangements of /3-(aryltelluro)propenoyl chlorides (83JA883 88MI4). 

Oxatellurolium compounds are stable in air as solids and in solution. They are not decomposed by light. Thermolysis at temperatures up to 300° and irradiation with unfiltered light from a Hanovia 450-V lamp failed to deposit tellurium. An X-ray structural study of 5-f4-methoxyphenyl)-3-phenyl-1,2-oxatellurolium chloride showed the Cl — Te —O bonds to be linear and to have bond orders of approximately 0.5. ... 

Naphthyl-3-phenyl-l,2-oxatellurolium Chloride 1.0 g (2.4 mmol) of 2-chlorocarbonyl-l-phenylethenyl 1-naphthyl tellurium is dissolved in 10 m/ of dry dichloromethane and the solution is cooled under nitrogen to — 78°. 0.35 g (2.6 mmol) of aluminum chloride arc added, the cooling bath is removed, and the mixture is allowed to warm to 20°. It is carefully poured into 200 ml of ice/water and extracted with three 50 ml portions of dichloromethane. The combined extracts are dried with anhydrous sodium sulfate, the solvent is evaporated, and the solid residue is recrystallizcd from methanol yield 0.82 g (82%) m.p. 135°. Examples of similarly prepared 1,2-oxatellurolium chlorides are ... 

Oxatellurolium chlorides (321) are produced by heating the acid chlorides... 

Diphenyl-l, 2-oxatelluroliuin Fluoride1 0.252 g (1.3 mmol) of sil ver tctrafhioroborate is dissolved in 20 ml of dry acetonitrile, 0.50 g (1.3 mmol) of 3,5-diphenyl-l,2-oxatellurolium chloride powder is added, and the resultant mixture is stirred at 20° under nitrogen for 3 h. The mixture is then filtered through a pad of Celite, the filtrate is concentrated, and the residue is dissolved in 50 ml of dichloromethane. This solution is washed with brine, dried with anhydrous sodium sulfate, filtered, and concentrated to cause the product to crystallize yield 0.16 g (33%) m.p. 88-90°. 

Methoxyphenyl)-3-phenyl-l,2-oxatelluroHum Trifluoroacetate1 0.20 g (1 mmol) of silver trifluoracetate is dissolved in 20 ml of dry benzene, 0.40 g (1 mmol) of 5-(4-methoxyphenyl)-3-phenyl-l, 2-oxatellurolium chloride powder is gradually added over 3 min, and the mixture is stirred at 20° for 1 h. The resultant mixture is filtered through a pad of Celite, and the filtrate is washed with brine, dried with anhydrous sodium sulfate, and evaporated. The residue is recrystallized from absolute ethanol yield 0.20 g (50%) m.p. 125-127°. 

Diphenyl-Tis-[1,2]oxatellurolo[2,3-b][l,2]oxatellurole was prepared from 3-methyl-5-phenyl-l,2-oxatellurolium chloride and benzoyl chloride in dichloromethane1. 

Methyl-5-plienyl-l,2-oxatellurolium Bromide 0.87 g (10 mmol) of anhydrous lithium bromide are dissolved in 20 ml of acetone, 0.61 g (2.0 mmol) of 3-methyl-5-phenyl-l,2-oxatellurolium chloride powder are added, and the mixture is heated under reflux for 10 min. The solvent is then evaporated under vacuum, the residue is shaken with a mixture of 40 ml of dichloromethane and 40 ml of water, and the organic phase is separated, dried with anhydrous sodium sulfate, filtered, and evaporated. The residue is recrystallized from acetonitrile yield 0.54 g (78%) m.p. 122°. 

Chlorocarbonylethcn-l-yl aryl tellurium derivatives, when dissolved in dichloromethane, isomerized in the presence of aluminum chloride to 1,2-oxatellurolium halides4. 

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