Diaryl-2.2-diiodide

The reaction was subsequently taken up by Antonchick, who developed suitable conditions for a reaction catalytic in iodine(lll) [6]. Initially, the authors could demonstrate that a combination of diacetoxyiodobenzene [Phl(OAc)2] in 1,1,1,3,3,3-hexafluoroisopropanol provided the corresponding carbazole 4 from precursor 3 in 81 % isolated yield. Subsequent development of a catalytic transformation identified the sterically congested l,l-diaryl,2,2-diiodide 7 as the optimum catalyst precursor. This compound is oxidized by peracetic acid tmder the reaction... 

Reduction of diaryltellurium dichlorides with samarium diiodide (typical procedure). Diaryl tellurium dichloride (1 mmol) was added to the deep blue solution of Sml2 (2.2 mmol) in THF (22 mL) at room temperature under nitrogen with stirring. The deep blue colour of the solution disappeared immediately and became yellow. The resulting solution was stirred at room temperature under nitrogen for 30 min. To the solution was added dilute hydrochloric acid, and the mixture was extracted with ether. The ethereal solution was washed with brine and dried over MgS04. The solvent was evaporated in vacuo, and the residue was purified by preparative TLC on silica gel (petroleum ether-methylene dichloride as eluent). 

Diaryltellurium dihalides (general procedure) The diaryl telluride dissolved in a small amount of benzene or CHCI3 is treated dropwise, while cooling (ice bath) and stirring, with a solution of an equimolar amount of SO2CI2, Br2 or I2 in the same solvent (in the case of SO2CI2, evolution of SO2 is observed). By addition of a large excess of petroleum ether at 30-60°C (50 mL for 1 mmol) the dihalide precipitates as a crystalline solid (the dichlorides are colourless, the dibromides yellow and the diiodides red). The yields are quantitative. 

Diaryl tellurium diiodides afford the iodocyclization of 4-pentenoic acid after 5 and 4 days reflux in CHCI3 in the presence of pyridine. ... 

Typical procedure A solution of 4-pentenoic acid (0.0500 g, 0.500 mmol), bis(p-chlorophenyl)tellurium diiodide (0.302 g, 0.500 mmol) and pyridine (0.040 g, 0.500 mmol) was heated at reflux in 20 mL of chloroform for 5 days. The reaction mixture was concentrated in vacuo, and the residue was purified via chromatography on silica gel eluted with 1 1 hexane/ethyl acetate to give 0.073 g (66%) of the iodolactone and 0.140 mg (80%) of diaryl telluride. 

In the synthesis of concave 1,10-phenanthroline cyclophanes 21 (Scheme 4), the aryl bridgeheads could be easily introduced by the addition of two aryl lithium moieties 16 to 1,10-phenanthroline (15). Although aryl lithium compounds may also be added to pyridine [23], this approach could not be realized for the construction of concave pyridine cyclophanes 29 yet [24]. Therefore another route for the synthesis of the concave pyridines 29 was used (Scheme 5) the cyclization of 1,5-diaryl substituted Cj-units 23 or 27 with ammonia. The resulting 2,6-bis(2,6-dimethoxyphenyl)pyridine 24 [25], the pyridine analogue to the tetramethoxy-1,10-phenanthroline derivative 17, was then treated in the same way. After liberation of the phenol functions, the four OH groups of 28 were reacted with two equivalents of diiodides 19 [25]. As in the synthesis of the concave 1,10-phenanthroline cyclophanes 21, two macrocycles were formed in one reaction step. 

Diaryl bond formation from properly functionalized precursors has been achieved (1) photochemically, (2) by oxidative coupling, and (3) by intramolecular coupling of diiodides. 

Bis[arylthio] tellurium derivatives reacted with methyl iodide at room temperature forming dimethyl tellurium diiodide and diaryl disulfanes2. 

Excess methyl iodide refluxed with diaryl ditellurium derivatives produced aryl methyl tellurium diiodide and aryl dimethyl telluronium iodides. 

The reactivity of the tellurium trihalides decreases from the chlorides to the iodides. The aryl tellurium triiodides do not form diaryl tellurium diiodides and do not react with acetone6. 

Diaryl ditellurium compounds refluxed with an excess of methyl iodide are converted to aryl methyl tellurium diiodides. 

Because diaryl tellurium diiodides are not hydrolyzed by boiling water, the diaryl tellurium hydroxide iodides were prepared by treating the hydroxide chlorides or bromides with potassium iodide1. 

Diaryl tellurium arenesulfonimides and excess dry methyl iodide in a sealed tube at 100° produced diaryl tellurium diiodides and /V-methyl arenesulfonamides2. With wet methyl iodide, bis[diphenyl tellurium iodide] oxide was formed2 ... 

Diaryl polonides are converted to the dibromides when they undergo reaction with Ar2TeBr2, Essentially, this is an oxidation reaction in which Po is oxidized from Po to Po and tellurium is reduced from Te to Te. Also, diaryl polonides add elemental bromine to form the dibromides. Thus, treatment of (C9Hu)2Po or (q -CioH7)2Po in benzene with bromine yields the dibromides. They can be precipitated by the addition of petroleum ether and recrystallized from benzene/petroleum ether. In a manner parallel to that just described, p-tolyl and Q -naphthylpolonium diiodides, Ar2Pol2, have been obtained by the addition of I2 to the respective diaryl polonides. 

Diaryl tellurium diacetates heated with methyl iodide in a sealed tube at 100° yielded diaryl tellurium diiodides ... 

Diorganotetrahalotellurates were prepared by combining diaryl tellurium dihalides, pentamethylene tellurium diiodide or tetramethylene tellurium diiodide with onium halides. These compounds were found to be 2 1 electrolytes by conductivity and molecular mass measurements. ... 

Two known synthesis routes were used to convert short-chained perfluoroalkylene dicarboxylic acid and diiodide intermediates to diaryl intermediates. The copper-catalyzed coupling of aryl and fluorocarbon iodides described by McLoughlin and Thrower (12) provided convenient synthesis of short-chained diphenylperfluoroalkylene compounds when appropriate fluorocarbon diiodides were available. The preparation of diaryl intermediates via aryl ketone synthesis and subsequent SF4 fluorination reaction provided a satisfactory alternative synthesis of lower-molecular-weight intermediates (13). 

Both PPSe and PPTe turn black and undergo weight Increases of 20 and 150%, respectively, on exposure to Iodine, with the conductivity of the PPSe samples being no more than 10 H(ohm-cm) l while the PPTe samples had a conductivity range of 10 -10 ohm-cm)-- -. Electron transfer does not appear to be involved in the interaction of I2 with PPSe and PPTe since the solid state spectra show the maxima of the original polymers with long tails into the near infrared. In the case of PPTe, the interaction with iodine largely involves formation of a tetracoordinate diaryl tellurium diiodide (24). Reduction of this material with sodium sulfide (24) leads to-recovered PPTe, identified by its IR spectrum. 

---